RetroArch/deps/dr/dr_flac.h

#ifndef dr_flac_h
#define dr_flac_h

#define DR_FLAC_NO_STDIO

#include <stdint.h>
#include <stddef.h>
#include <retro_inline.h>

typedef int8_t           drflac_int8;
typedef uint8_t          drflac_uint8;
typedef int16_t          drflac_int16;
typedef uint16_t         drflac_uint16;
typedef int32_t          drflac_int32;
typedef uint32_t         drflac_uint32;
typedef int64_t          drflac_int64;
typedef uint64_t         drflac_uint64;
typedef drflac_uint8     drflac_bool8;
typedef drflac_uint32    drflac_bool32;
#define DRFLAC_TRUE      1
#define DRFLAC_FALSE     0

/* As data is read from the client it is placed into an internal buffer for fast access. This controls the
 * size of that buffer. Larger values means more speed, but also more memory. In my testing there is diminishing
 * returns after about 4KB, but you can fiddle with this to suit your own needs. Must be a multiple of 8.
 */
#ifndef DR_FLAC_BUFFER_SIZE
#define DR_FLAC_BUFFER_SIZE   4096
#endif

#ifdef __cplusplus
extern "C" {
#endif

/* Check if we can enable 64-bit optimizations. */
#if defined(_WIN64)
#define DRFLAC_64BIT
#endif

#if defined(__GNUC__)
#if defined(__x86_64__) || defined(__ppc64__)
#define DRFLAC_64BIT
#endif
#endif

#ifdef DRFLAC_64BIT
typedef drflac_uint64 drflac_cache_t;
#else
typedef drflac_uint32 drflac_cache_t;
#endif

/* The various metadata block types. */
#define DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO       0
#define DRFLAC_METADATA_BLOCK_TYPE_PADDING          1
#define DRFLAC_METADATA_BLOCK_TYPE_APPLICATION      2
#define DRFLAC_METADATA_BLOCK_TYPE_SEEKTABLE        3
#define DRFLAC_METADATA_BLOCK_TYPE_VORBIS_COMMENT   4
#define DRFLAC_METADATA_BLOCK_TYPE_CUESHEET         5
#define DRFLAC_METADATA_BLOCK_TYPE_PICTURE          6
#define DRFLAC_METADATA_BLOCK_TYPE_INVALID          127

/* The various picture types specified in the PICTURE block. */
#define DRFLAC_PICTURE_TYPE_OTHER                   0
#define DRFLAC_PICTURE_TYPE_FILE_ICON               1
#define DRFLAC_PICTURE_TYPE_OTHER_FILE_ICON         2
#define DRFLAC_PICTURE_TYPE_COVER_FRONT             3
#define DRFLAC_PICTURE_TYPE_COVER_BACK              4
#define DRFLAC_PICTURE_TYPE_LEAFLET_PAGE            5
#define DRFLAC_PICTURE_TYPE_MEDIA                   6
#define DRFLAC_PICTURE_TYPE_LEAD_ARTIST             7
#define DRFLAC_PICTURE_TYPE_ARTIST                  8
#define DRFLAC_PICTURE_TYPE_CONDUCTOR               9
#define DRFLAC_PICTURE_TYPE_BAND                    10
#define DRFLAC_PICTURE_TYPE_COMPOSER                11
#define DRFLAC_PICTURE_TYPE_LYRICIST                12
#define DRFLAC_PICTURE_TYPE_RECORDING_LOCATION      13
#define DRFLAC_PICTURE_TYPE_DURING_RECORDING        14
#define DRFLAC_PICTURE_TYPE_DURING_PERFORMANCE      15
#define DRFLAC_PICTURE_TYPE_SCREEN_CAPTURE          16
#define DRFLAC_PICTURE_TYPE_BRIGHT_COLORED_FISH     17
#define DRFLAC_PICTURE_TYPE_ILLUSTRATION            18
#define DRFLAC_PICTURE_TYPE_BAND_LOGOTYPE           19
#define DRFLAC_PICTURE_TYPE_PUBLISHER_LOGOTYPE      20

typedef enum
{
    drflac_container_native,
    drflac_container_ogg,
    drflac_container_unknown
} drflac_container;

typedef enum
{
    drflac_seek_origin_start,
    drflac_seek_origin_current
} drflac_seek_origin;

/* Packing is important on this structure because we map this directly to the raw data within the SEEKTABLE metadata block. */
#pragma pack(2)
typedef struct
{
    drflac_uint64 firstSample;
    drflac_uint64 frameOffset;   /* The offset from the first byte of the header of the first frame. */
    drflac_uint16 sampleCount;
} drflac_seekpoint;
#pragma pack()

typedef struct
{
    drflac_uint16 minBlockSize;
    drflac_uint16 maxBlockSize;
    drflac_uint32 minFrameSize;
    drflac_uint32 maxFrameSize;
    drflac_uint32 sampleRate;
    drflac_uint8  channels;
    drflac_uint8  bitsPerSample;
    drflac_uint64 totalSampleCount;
    drflac_uint8  md5[16];
} drflac_streaminfo;

typedef struct
{
    /* The metadata type. Use this to know how to interpret the data below. */
    drflac_uint32 type;

    /* A pointer to the raw data. This points to a temporary buffer so don't hold on to it. It's best to
     * not modify the contents of this buffer. Use the structures below for more meaningful and structured
     * information about the metadata. It's possible for this to be null.
     */
    const void* pRawData;

    /* The size in bytes of the block and the buffer pointed to by pRawData if it's non-NULL. */
    drflac_uint32 rawDataSize;

    union
    {
        drflac_streaminfo streaminfo;

        struct
        {
            int unused;
        } padding;

        struct
        {
            drflac_uint32 id;
            const void* pData;
            drflac_uint32 dataSize;
        } application;

        struct
        {
            drflac_uint32 seekpointCount;
            const drflac_seekpoint* pSeekpoints;
        } seektable;

        struct
        {
            drflac_uint32 vendorLength;
            const char* vendor;
            drflac_uint32 commentCount;
            const char* comments;
        } vorbis_comment;

        struct
        {
            char catalog[128];
            drflac_uint64 leadInSampleCount;
            drflac_bool32 isCD;
            drflac_uint8 trackCount;
            const drflac_uint8* pTrackData;
        } cuesheet;

        struct
        {
            drflac_uint32 type;
            drflac_uint32 mimeLength;
            const char* mime;
            drflac_uint32 descriptionLength;
            const char* description;
            drflac_uint32 width;
            drflac_uint32 height;
            drflac_uint32 colorDepth;
            drflac_uint32 indexColorCount;
            drflac_uint32 pictureDataSize;
            const drflac_uint8* pPictureData;
        } picture;
    } data;
} drflac_metadata;


/* Callback for when data needs to be read from the client.
 *
 * pUserData   [in]  The user data that was passed to drflac_open() and family.
 * pBufferOut  [out] The output buffer.
 * bytesToRead [in]  The number of bytes to read.
 *
 * Returns the number of bytes actually read.
 *
 * A return value of less than bytesToRead indicates the end of the stream. Do _not_ return from this callback until
 * either the entire bytesToRead is filled or you have reached the end of the stream.
 */
typedef size_t (* drflac_read_proc)(void* pUserData, void* pBufferOut, size_t bytesToRead);

/* Callback for when data needs to be seeked.
 *
 * pUserData [in] The user data that was passed to drflac_open() and family.
 * offset    [in] The number of bytes to move, relative to the origin. Will never be negative.
 * origin    [in] The origin of the seek - the current position or the start of the stream.
 *
 * Returns whether or not the seek was successful.
 *
 * The offset will never be negative. Whether or not it is relative to the beginning or current position is determined
 * by the "origin" parameter which will be either drflac_seek_origin_start or drflac_seek_origin_current.
 */
typedef drflac_bool32 (* drflac_seek_proc)(void* pUserData, int offset, drflac_seek_origin origin);

/* Callback for when a metadata block is read.
 *
 * pUserData [in] The user data that was passed to drflac_open() and family.
 * pMetadata [in] A pointer to a structure containing the data of the metadata block.
 *
 * Use pMetadata->type to determine which metadata block is being handled and how to read the data.
 */
typedef void (* drflac_meta_proc)(void* pUserData, drflac_metadata* pMetadata);


/* Structure for internal use. Only used for decoders opened with drflac_open_memory. */
typedef struct
{
    const drflac_uint8* data;
    size_t dataSize;
    size_t currentReadPos;
} drflac__memory_stream;

/* Structure for internal use. Used for bit streaming. */
typedef struct
{
    /* The function to call when more data needs to be read. */
    drflac_read_proc onRead;

    /* The function to call when the current read position needs to be moved. */
    drflac_seek_proc onSeek;

    /* The user data to pass around to onRead and onSeek. */
    void* pUserData;


    /* The number of unaligned bytes in the L2 cache. This will always be 0 until the end of the stream is hit. At the end of the
     * stream there will be a number of bytes that don't cleanly fit in an L1 cache line, so we use this variable to know whether
     * or not the bistreamer needs to run on a slower path to read those last bytes. This will never be more than sizeof(drflac_cache_t).
     */
    size_t unalignedByteCount;

    /* The content of the unaligned bytes. */
    drflac_cache_t unalignedCache;

    /* The index of the next valid cache line in the "L2" cache. */
    drflac_uint32 nextL2Line;

    /* The number of bits that have been consumed by the cache. This is used to determine how many valid bits are remaining. */
    drflac_uint32 consumedBits;

    /* The cached data which was most recently read from the client. There are two levels of cache. Data flows as such:
     * Client -> L2 -> L1. The L2 -> L1 movement is aligned and runs on a fast path in just a few instructions. */
    drflac_cache_t cacheL2[DR_FLAC_BUFFER_SIZE/sizeof(drflac_cache_t)];
    drflac_cache_t cache;

    /* CRC-16. This is updated whenever bits are read from the bit stream. Manually set this to 0 to reset the CRC. For FLAC, this
     * is reset to 0 at the beginning of each frame. */
    drflac_uint16 crc16;
    drflac_cache_t crc16Cache;              /* A cache for optimizing CRC calculations. This is filled when when the L1 cache is reloaded. */
    drflac_uint32 crc16CacheIgnoredBytes;   /* The number of bytes to ignore when updating the CRC-16 from the CRC-16 cache. */
} drflac_bs;

typedef struct
{
    /* The type of the subframe: SUBFRAME_CONSTANT, SUBFRAME_VERBATIM, SUBFRAME_FIXED or SUBFRAME_LPC. */
    drflac_uint8 subframeType;

    /* The number of wasted bits per sample as specified by the sub-frame header. */
    drflac_uint8 wastedBitsPerSample;

    /* The order to use for the prediction stage for SUBFRAME_FIXED and SUBFRAME_LPC. */
    drflac_uint8 lpcOrder;

    /* The number of bits per sample for this subframe. This is not always equal to the current frame's bit per sample because
     * an extra bit is required for side channels when interchannel decorrelation is being used. */
    drflac_uint32 bitsPerSample;

    /* A pointer to the buffer containing the decoded samples in the subframe. This pointer is an offset from drflac::pExtraData. Note that
     * it's a signed 32-bit integer for each value. */
    drflac_int32* pDecodedSamples;
} drflac_subframe;

typedef struct
{
    /* If the stream uses variable block sizes, this will be set to the index of the first sample. If fixed block sizes are used, this will
     * always be set to 0. */
    drflac_uint64 sampleNumber;

    /* If the stream uses fixed block sizes, this will be set to the frame number. If variable block sizes are used, this will always be 0. */
    drflac_uint32 frameNumber;

    /* The sample rate of this frame. */
    drflac_uint32 sampleRate;

    /* The number of samples in each sub-frame within this frame. */
    drflac_uint16 blockSize;

    /* The channel assignment of this frame. This is not always set to the channel count. If interchannel decorrelation is being used this
     * will be set to DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE, DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE or DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE. */
    drflac_uint8 channelAssignment;

    /* The number of bits per sample within this frame. */
    drflac_uint8 bitsPerSample;

    /* The frame's CRC. */
    drflac_uint8 crc8;
} drflac_frame_header;

typedef struct
{
    /* The header. */
    drflac_frame_header header;

    /* The number of samples left to be read in this frame. This is initially set to the block size multiplied by the channel count. As samples
     * are read, this will be decremented. When it reaches 0, the decoder will see this frame as fully consumed and load the next frame.
     */
    drflac_uint32 samplesRemaining;

    /* The list of sub-frames within the frame. There is one sub-frame for each channel, and there's a maximum of 8 channels. */
    drflac_subframe subframes[8];
} drflac_frame;

typedef struct
{
    /* The function to call when a metadata block is read. */
    drflac_meta_proc onMeta;

    /* The user data posted to the metadata callback function. */
    void* pUserDataMD;


    /* The sample rate. Will be set to something like 44100. */
    drflac_uint32 sampleRate;

    /* The number of channels. This will be set to 1 for monaural streams, 2 for stereo, etc. Maximum 8. This is set based on the
     * value specified in the STREAMINFO block. */
    drflac_uint8 channels;

    /* The bits per sample. Will be set to somthing like 16, 24, etc. */
    drflac_uint8 bitsPerSample;

    /* The maximum block size, in samples. This number represents the number of samples in each channel (not combined). */
    drflac_uint16 maxBlockSize;

    /* The total number of samples making up the stream. This includes every channel. For example, if the stream has 2 channels,
     * with each channel having a total of 4096, this value will be set to 2*4096 = 8192. Can be 0 in which case it's still a
     * valid stream, but just means the total sample count is unknown. Likely the case with streams like internet radio. */
    drflac_uint64 totalSampleCount;


    /* The container type. This is set based on whether or not the decoder was opened from a native or Ogg stream. */
    drflac_container container;

    /* The position of the seektable in the file. */
    drflac_uint64 seektablePos;

    /* The size of the seektable. */
    drflac_uint32 seektableSize;


    /* Information about the frame the decoder is currently sitting on. */
    drflac_frame currentFrame;

    /* The position of the first frame in the stream. This is only ever used for seeking. */
    drflac_uint64 firstFramePos;


    /* A hack to avoid a malloc() when opening a decoder with drflac_open_memory(). */
    drflac__memory_stream memoryStream;


    /* A pointer to the decoded sample data. This is an offset of pExtraData. */
    drflac_int32* pDecodedSamples;

    /* Internal use only. Only used with Ogg containers. Points to a drflac_oggbs object. This is an offset of pExtraData. */
    void* _oggbs;

    /* The bit streamer. The raw FLAC data is fed through this object. */
    drflac_bs bs;

    /* Variable length extra data. We attach this to the end of the object so we can avoid unnecessary mallocs. */
    drflac_uint8 pExtraData[1];
} drflac;


/* Opens a FLAC decoder.
 *
 * onRead    [in]           The function to call when data needs to be read from the client.
 * onSeek    [in]           The function to call when the read position of the client data needs to move.
 * pUserData [in, optional] A pointer to application defined data that will be passed to onRead and onSeek.
 *
 * Returns a pointer to an object representing the decoder.
 *
 * Close the decoder with drflac_close().
 *
 * This function will automatically detect whether or not you are attempting to open a native or Ogg encapsulated
 * FLAC, both of which should work seamlessly without any manual intervention. Ogg encapsulation also works with
 * multiplexed streams which basically means it can play FLAC encoded audio tracks in videos.
 *
 * This is the lowest level function for opening a FLAC stream. You can also use drflac_open_file() and drflac_open_memory()
 * to open the stream from a file or from a block of memory respectively.
 *
 * The STREAMINFO block must be present for this to succeed. Use drflac_open_relaxed() to open a FLAC stream where
 * the header may not be present.
 *
 * See also: drflac_open_file(), drflac_open_memory(), drflac_open_with_metadata(), drflac_close()
 */
drflac* drflac_open(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData);

/* The same as drflac_open(), except attempts to open the stream even when a header block is not present.
 *
 * Because the header is not necessarily available, the caller must explicitly define the container (Native or Ogg). Do
 * not set this to drflac_container_unknown - that is for internal use only.
 *
 * Opening in relaxed mode will continue reading data from onRead until it finds a valid frame. If a frame is never
 * found it will continue forever. To abort, force your onRead callback to return 0, which dr_flac will use as an
 * indicator that the end of the stream was found. */
drflac* drflac_open_relaxed(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_container container, void* pUserData);

/* Opens a FLAC decoder and notifies the caller of the metadata chunks (album art, etc.).
 *
 * onRead    [in]           The function to call when data needs to be read from the client.
 * onSeek    [in]           The function to call when the read position of the client data needs to move.
 * onMeta    [in]           The function to call for every metadata block.
 * pUserData [in, optional] A pointer to application defined data that will be passed to onRead, onSeek and onMeta.
 *
 * Returns a pointer to an object representing the decoder.
 *
 * Close the decoder with drflac_close().
 *
 * This is slower than drflac_open(), so avoid this one if you don't need metadata. Internally, this will do a DRFLAC_MALLOC()
 * and DRFLAC_FREE() for every metadata block except for STREAMINFO and PADDING blocks.
 *
 * The caller is notified of the metadata via the onMeta callback. All metadata blocks will be handled before the function
 * returns.
 *
 * The STREAMINFO block must be present for this to succeed. Use drflac_open_with_metadata_relaxed() to open a FLAC
 * stream where the header may not be present.
 *
 * Note that this will behave inconsistently with drflac_open() if the stream is an Ogg encapsulated stream and a metadata
 * block is corrupted. This is due to the way the Ogg stream recovers from corrupted pages. When drflac_open_with_metadata()
 * is being used, the open routine will try to read the contents of the metadata block, whereas drflac_open() will simply
 * seek past it (for the sake of efficiency). This inconsistency can result in different samples being returned depending on
 * whether or not the stream is being opened with metadata.
 *
 * See also: drflac_open_file_with_metadata(), drflac_open_memory_with_metadata(), drflac_open(), drflac_close()
 */
drflac* drflac_open_with_metadata(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, void* pUserData);

/* The same as drflac_open_with_metadata(), except attemps to open the stream even when a header block is not present.
 *
 * See also: drflac_open_with_metadata(), drflac_open_relaxed()
 */
drflac* drflac_open_with_metadata_relaxed(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, drflac_container container, void* pUserData);

/* Closes the given FLAC decoder.
 *
 * pFlac [in] The decoder to close.
 *
 * This will destroy the decoder object. */
void drflac_close(drflac* pFlac);


/* Reads sample data from the given FLAC decoder, output as interleaved signed 32-bit PCM.
 *
 * pFlac         [in]            The decoder.
 * samplesToRead [in]            The number of samples to read.
 * pBufferOut    [out, optional] A pointer to the buffer that will receive the decoded samples.
 *
 * Returns the number of samples actually read.
 *
 * pBufferOut can be null, in which case the call will act as a seek, and the return value will be the number of samples
 * seeked. */
drflac_uint64 drflac_read_s32(drflac* pFlac, drflac_uint64 samplesToRead, drflac_int32* pBufferOut);

/* Same as drflac_read_s32(), except outputs samples as 16-bit integer PCM rather than 32-bit.
 *
 * pFlac         [in]            The decoder.
 * samplesToRead [in]            The number of samples to read.
 * pBufferOut    [out, optional] A pointer to the buffer that will receive the decoded samples.
 *
 * Returns the number of samples actually read.
 *
 * pBufferOut can be null, in which case the call will act as a seek, and the return value will be the number of samples
 * seeked.
 *
 * Note that this is lossy for streams where the bits per sample is larger than 16.
 */
drflac_uint64 drflac_read_s16(drflac* pFlac, drflac_uint64 samplesToRead, drflac_int16* pBufferOut);

/* Same as drflac_read_s32(), except outputs samples as 32-bit floating-point PCM.
 *
 * pFlac         [in]            The decoder.
 * samplesToRead [in]            The number of samples to read.
 * pBufferOut    [out, optional] A pointer to the buffer that will receive the decoded samples.
 *
 * Returns the number of samples actually read.
 *
 * pBufferOut can be null, in which case the call will act as a seek, and the return value will be the number of samples
 * seeked.
 *
 * Note that this should be considered lossy due to the nature of floating point numbers not being able to exactly
 * represent every possible number.
 */
drflac_uint64 drflac_read_f32(drflac* pFlac, drflac_uint64 samplesToRead, float* pBufferOut);

/* Seeks to the sample at the given index.
 *
 * pFlac       [in] The decoder.
 * sampleIndex [in] The index of the sample to seek to. See notes below.
 *
 * Returns DRFLAC_TRUE if successful; DRFLAC_FALSE otherwise.
 *
 * The sample index is based on interleaving. In a stereo stream, for example, the sample at index 0 is the first sample
 * in the left channel; the sample at index 1 is the first sample on the right channel, and so on.
 *
 * When seeking, you will likely want to ensure it's rounded to a multiple of the channel count. You can do this with
 * something like drflac_seek_to_sample(pFlac, (mySampleIndex + (mySampleIndex % pFlac->channels)))
 */
drflac_bool32 drflac_seek_to_sample(drflac* pFlac, drflac_uint64 sampleIndex);



#ifndef DR_FLAC_NO_STDIO
/* Opens a FLAC decoder from the file at the given path.
 *
 * filename [in] The path of the file to open, either absolute or relative to the current directory.
 *
 * Returns a pointer to an object representing the decoder.
 *
 * Close the decoder with drflac_close().
 *
 * This will hold a handle to the file until the decoder is closed with drflac_close(). Some platforms will restrict the
 * number of files a process can have open at any given time, so keep this mind if you have many decoders open at the
 * same time.
 *
 * See also: drflac_open(), drflac_open_file_with_metadata(), drflac_close()
 */
drflac* drflac_open_file(const char* filename);

/* Opens a FLAC decoder from the file at the given path and notifies the caller of the metadata chunks (album art, etc.)
 *
 * Look at the documentation for drflac_open_with_metadata() for more information on how metadata is handled.
 */
drflac* drflac_open_file_with_metadata(const char* filename, drflac_meta_proc onMeta, void* pUserData);
#endif

/* Opens a FLAC decoder from a pre-allocated block of memory
 *
 * This does not create a copy of the data. It is up to the application to ensure the buffer remains valid for
 * the lifetime of the decoder.
 */
drflac* drflac_open_memory(const void* data, size_t dataSize);

/* Opens a FLAC decoder from a pre-allocated block of memory and notifies the caller of the metadata chunks (album art, etc.)
 *
 * Look at the documentation for drflac_open_with_metadata() for more information on how metadata is handled.
 */
drflac* drflac_open_memory_with_metadata(const void* data, size_t dataSize, drflac_meta_proc onMeta, void* pUserData);

/* High Level APIs */

/* Opens a FLAC stream from the given callbacks and fully decodes it in a single operation. The return value is a
 * pointer to the sample data as interleaved signed 32-bit PCM. The returned data must be freed with DRFLAC_FREE().
 *
 * Sometimes a FLAC file won't keep track of the total sample count. In this situation the function will continuously
 * read samples into a dynamically sized buffer on the heap until no samples are left.
 *
 * Do not call this function on a broadcast type of stream (like internet radio streams and whatnot).
 */
drflac_int32* drflac_open_and_decode_s32(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Same as drflac_open_and_decode_s32(), except returns signed 16-bit integer samples. */
drflac_int16* drflac_open_and_decode_s16(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Same as drflac_open_and_decode_s32(), except returns 32-bit floating-point samples. */
float* drflac_open_and_decode_f32(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

#ifndef DR_FLAC_NO_STDIO
/* Same as drflac_open_and_decode_s32() except opens the decoder from a file. */
drflac_int32* drflac_open_and_decode_file_s32(const char* filename, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Same as drflac_open_and_decode_file_s32(), except returns signed 16-bit integer samples. */
drflac_int16* drflac_open_and_decode_file_s16(const char* filename, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Same as drflac_open_and_decode_file_f32(), except returns 32-bit floating-point samples. */
float* drflac_open_and_decode_file_f32(const char* filename, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);
#endif

/* Same as drflac_open_and_decode_s32() except opens the decoder from a block of memory. */
drflac_int32* drflac_open_and_decode_memory_s32(const void* data, size_t dataSize, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Same as drflac_open_and_decode_memory_s32(), except returns signed 16-bit integer samples. */
drflac_int16* drflac_open_and_decode_memory_s16(const void* data, size_t dataSize, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Same as drflac_open_and_decode_memory_s32(), except returns 32-bit floating-point samples. */
float* drflac_open_and_decode_memory_f32(const void* data, size_t dataSize, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount);

/* Frees memory that was allocated internally by dr_flac. */
void drflac_free(void* p);


/* Structure representing an iterator for vorbis comments in a VORBIS_COMMENT metadata block. */
typedef struct
{
    drflac_uint32 countRemaining;
    const char* pRunningData;
} drflac_vorbis_comment_iterator;

/* Initializes a vorbis comment iterator. This can be used for iterating over the vorbis comments in a VORBIS_COMMENT
 * metadata block. */
void drflac_init_vorbis_comment_iterator(drflac_vorbis_comment_iterator* pIter, drflac_uint32 commentCount, const char* pComments);

/* Goes to the next vorbis comment in the given iterator. If null is returned it means there are no more comments. The
 * returned string is NOT null terminated. */
const char* drflac_next_vorbis_comment(drflac_vorbis_comment_iterator* pIter, drflac_uint32* pCommentLengthOut);



#ifdef __cplusplus
}
#endif
#endif  /* dr_flac_h */


/*
 *
 * IMPLEMENTATION
 *
 */
#ifdef DR_FLAC_IMPLEMENTATION
#include <stdlib.h>
#include <string.h>

/* CPU architecture. */
#if defined(__x86_64__) || defined(_M_X64)
#define DRFLAC_X64
#elif defined(__i386) || defined(_M_IX86)
#define DRFLAC_X86
#elif defined(__arm__) || defined(_M_ARM)
#define DRFLAC_ARM
#endif

/* Compile-time CPU feature support. */
#if !defined(DR_FLAC_NO_SIMD) && (defined(DRFLAC_X86) || defined(DRFLAC_X64))
    #if defined(_MSC_VER) && !defined(__clang__)
        #if _MSC_VER >= 1400
            #include <intrin.h>
            static void drflac__cpuid(int info[4], int fid)
            {
                __cpuid(info, fid);
            }
        #else
        #define DRFLAC_NO_CPUID
        #endif
    #else
        #if defined(__GNUC__) || defined(__clang__)
            static void drflac__cpuid(int info[4], int fid)
            {
                __asm__ __volatile__ (
                    "cpuid" : "=a"(info[0]), "=b"(info[1]), "=c"(info[2]), "=d"(info[3]) : "a"(fid), "c"(0)
                );
            }
        #else
        #define DRFLAC_NO_CPUID
        #endif
    #endif
#else
#define DRFLAC_NO_CPUID
#endif


#ifdef __linux__
#define _BSD_SOURCE
#include <endian.h>
#endif

#if defined(_MSC_VER) && _MSC_VER >= 1500 && (defined(DRFLAC_X86) || defined(DRFLAC_X64))
#define DRFLAC_HAS_LZCNT_INTRINSIC
#elif (defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7)))
#define DRFLAC_HAS_LZCNT_INTRINSIC
#elif defined(__clang__)
    #if __has_builtin(__builtin_clzll) || __has_builtin(__builtin_clzl)
    #define DRFLAC_HAS_LZCNT_INTRINSIC
    #endif
#endif

#if defined(_MSC_VER) && _MSC_VER >= 1300
#define DRFLAC_HAS_BYTESWAP_INTRINSIC
#elif defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
#define DRFLAC_HAS_BYTESWAP_INTRINSIC
#elif defined(__clang__)
    #if __has_builtin(__builtin_bswap16) && __has_builtin(__builtin_bswap32) && __has_builtin(__builtin_bswap64)
    #define DRFLAC_HAS_BYTESWAP_INTRINSIC
    #endif
#endif

/* Standard library stuff. */
#ifndef DRFLAC_ASSERT
#include <assert.h>
#define DRFLAC_ASSERT(expression)           assert(expression)
#endif
#ifndef DRFLAC_MALLOC
#define DRFLAC_MALLOC(sz)                   malloc((sz))
#endif
#ifndef DRFLAC_REALLOC
#define DRFLAC_REALLOC(p, sz)               realloc((p), (sz))
#endif
#ifndef DRFLAC_FREE
#define DRFLAC_FREE(p)                      free((p))
#endif
#ifndef DRFLAC_COPY_MEMORY
#define DRFLAC_COPY_MEMORY(dst, src, sz)    memcpy((dst), (src), (sz))
#endif
#ifndef DRFLAC_ZERO_MEMORY
#define DRFLAC_ZERO_MEMORY(p, sz)           memset((p), 0, (sz))
#endif

#define DRFLAC_MAX_SIMD_VECTOR_SIZE                     64  /* 64 for AVX-512 in the future. */

#ifdef _MSC_VER
#define DRFLAC_INLINE __forceinline
#else
#ifdef __GNUC__
#define DRFLAC_INLINE INLINE __attribute__((always_inline))
#else
#define DRFLAC_INLINE INLINE
#endif
#endif

typedef drflac_int32 drflac_result;
#define DRFLAC_SUCCESS                                  0
#define DRFLAC_ERROR                                    -1  /* A generic error. */
#define DRFLAC_INVALID_ARGS                             -2
#define DRFLAC_END_OF_STREAM                            -128
#define DRFLAC_CRC_MISMATCH                             -129

#define DRFLAC_SUBFRAME_CONSTANT                        0
#define DRFLAC_SUBFRAME_VERBATIM                        1
#define DRFLAC_SUBFRAME_FIXED                           8
#define DRFLAC_SUBFRAME_LPC                             32
#define DRFLAC_SUBFRAME_RESERVED                        255

#define DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE  0
#define DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE2 1

#define DRFLAC_CHANNEL_ASSIGNMENT_INDEPENDENT           0
#define DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE             8
#define DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE            9
#define DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE              10


#define drflac_align(x, a)                              ((((x) + (a) - 1) / (a)) * (a))
#define drflac_assert                                   DRFLAC_ASSERT
#define drflac_copy_memory                              DRFLAC_COPY_MEMORY
#define drflac_zero_memory                              DRFLAC_ZERO_MEMORY

/* CPU caps. */
static drflac_bool32 drflac__gIsLZCNTSupported = DRFLAC_FALSE;
#ifndef DRFLAC_NO_CPUID
static drflac_bool32 drflac__gIsSSE42Supported = DRFLAC_FALSE;
static void drflac__init_cpu_caps()
{
    int info[4] = {0};

    /* LZCNT */
    drflac__cpuid(info, 0x80000001);
    drflac__gIsLZCNTSupported = (info[2] & (1 <<  5)) != 0;

    /* SSE4.2 */
    drflac__cpuid(info, 1);
    drflac__gIsSSE42Supported = (info[2] & (1 << 19)) != 0;
}
#endif


/* Endian Management */
static DRFLAC_INLINE drflac_bool32 drflac__is_little_endian()
{
#if defined(DRFLAC_X86) || defined(DRFLAC_X64)
    return DRFLAC_TRUE;
#else
    int n = 1;
    return (*(char*)&n) == 1;
#endif
}

static DRFLAC_INLINE drflac_uint16 drflac__swap_endian_uint16(drflac_uint16 n)
{
#ifdef DRFLAC_HAS_BYTESWAP_INTRINSIC
    #if defined(_MSC_VER)
        return _byteswap_ushort(n);
    #elif defined(__GNUC__) || defined(__clang__)
        return __builtin_bswap16(n);
    #else
        #error "This compiler does not support the byte swap intrinsic."
    #endif
#else
    return ((n & 0xFF00) >> 8) |
           ((n & 0x00FF) << 8);
#endif
}

static DRFLAC_INLINE drflac_uint32 drflac__swap_endian_uint32(drflac_uint32 n)
{
#ifdef DRFLAC_HAS_BYTESWAP_INTRINSIC
    #if defined(_MSC_VER)
        return _byteswap_ulong(n);
    #elif defined(__GNUC__) || defined(__clang__)
        return __builtin_bswap32(n);
    #else
        #error "This compiler does not support the byte swap intrinsic."
    #endif
#else
    return ((n & 0xFF000000) >> 24) |
           ((n & 0x00FF0000) >>  8) |
           ((n & 0x0000FF00) <<  8) |
           ((n & 0x000000FF) << 24);
#endif
}

static DRFLAC_INLINE drflac_uint64 drflac__swap_endian_uint64(drflac_uint64 n)
{
#ifdef DRFLAC_HAS_BYTESWAP_INTRINSIC
    #if defined(_MSC_VER)
        return _byteswap_uint64(n);
    #elif defined(__GNUC__) || defined(__clang__)
        return __builtin_bswap64(n);
    #else
        #error "This compiler does not support the byte swap intrinsic."
    #endif
#else
    return ((n & (drflac_uint64)0xFF00000000000000) >> 56) |
           ((n & (drflac_uint64)0x00FF000000000000) >> 40) |
           ((n & (drflac_uint64)0x0000FF0000000000) >> 24) |
           ((n & (drflac_uint64)0x000000FF00000000) >>  8) |
           ((n & (drflac_uint64)0x00000000FF000000) <<  8) |
           ((n & (drflac_uint64)0x0000000000FF0000) << 24) |
           ((n & (drflac_uint64)0x000000000000FF00) << 40) |
           ((n & (drflac_uint64)0x00000000000000FF) << 56);
#endif
}


static DRFLAC_INLINE drflac_uint16 drflac__be2host_16(drflac_uint16 n)
{
#ifdef __linux__
    return be16toh(n);
#else
    if (drflac__is_little_endian())
        return drflac__swap_endian_uint16(n);

    return n;
#endif
}

static DRFLAC_INLINE drflac_uint32 drflac__be2host_32(drflac_uint32 n)
{
#ifdef __linux__
    return be32toh(n);
#else
    if (drflac__is_little_endian())
        return drflac__swap_endian_uint32(n);

    return n;
#endif
}

static DRFLAC_INLINE drflac_uint64 drflac__be2host_64(drflac_uint64 n)
{
#ifdef __linux__
    return be64toh(n);
#else
    if (drflac__is_little_endian())
        return drflac__swap_endian_uint64(n);

    return n;
#endif
}


static DRFLAC_INLINE drflac_uint32 drflac__le2host_32(drflac_uint32 n)
{
#ifdef __linux__
    return le32toh(n);
#else
    if (!drflac__is_little_endian())
        return drflac__swap_endian_uint32(n);

    return n;
#endif
}


static DRFLAC_INLINE drflac_uint32 drflac__unsynchsafe_32(drflac_uint32 n)
{
    drflac_uint32 result = 0;
    result |= (n & 0x7F000000) >> 3;
    result |= (n & 0x007F0000) >> 2;
    result |= (n & 0x00007F00) >> 1;
    result |= (n & 0x0000007F) >> 0;

    return result;
}

/* The CRC code below is based on this document: http://zlib.net/crc_v3.txt */
static drflac_uint8 drflac__crc8_table[] = {
    0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15, 0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,
    0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65, 0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,
    0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5, 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
    0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85, 0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,
    0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2, 0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,
    0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2, 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
    0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32, 0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,
    0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42, 0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,
    0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C, 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
    0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC, 0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,
    0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C, 0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,
    0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C, 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
    0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B, 0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,
    0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B, 0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,
    0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB, 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
    0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB, 0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3
};

static drflac_uint16 drflac__crc16_table[] = {
    0x0000, 0x8005, 0x800F, 0x000A, 0x801B, 0x001E, 0x0014, 0x8011,
    0x8033, 0x0036, 0x003C, 0x8039, 0x0028, 0x802D, 0x8027, 0x0022,
    0x8063, 0x0066, 0x006C, 0x8069, 0x0078, 0x807D, 0x8077, 0x0072,
    0x0050, 0x8055, 0x805F, 0x005A, 0x804B, 0x004E, 0x0044, 0x8041,
    0x80C3, 0x00C6, 0x00CC, 0x80C9, 0x00D8, 0x80DD, 0x80D7, 0x00D2,
    0x00F0, 0x80F5, 0x80FF, 0x00FA, 0x80EB, 0x00EE, 0x00E4, 0x80E1,
    0x00A0, 0x80A5, 0x80AF, 0x00AA, 0x80BB, 0x00BE, 0x00B4, 0x80B1,
    0x8093, 0x0096, 0x009C, 0x8099, 0x0088, 0x808D, 0x8087, 0x0082,
    0x8183, 0x0186, 0x018C, 0x8189, 0x0198, 0x819D, 0x8197, 0x0192,
    0x01B0, 0x81B5, 0x81BF, 0x01BA, 0x81AB, 0x01AE, 0x01A4, 0x81A1,
    0x01E0, 0x81E5, 0x81EF, 0x01EA, 0x81FB, 0x01FE, 0x01F4, 0x81F1,
    0x81D3, 0x01D6, 0x01DC, 0x81D9, 0x01C8, 0x81CD, 0x81C7, 0x01C2,
    0x0140, 0x8145, 0x814F, 0x014A, 0x815B, 0x015E, 0x0154, 0x8151,
    0x8173, 0x0176, 0x017C, 0x8179, 0x0168, 0x816D, 0x8167, 0x0162,
    0x8123, 0x0126, 0x012C, 0x8129, 0x0138, 0x813D, 0x8137, 0x0132,
    0x0110, 0x8115, 0x811F, 0x011A, 0x810B, 0x010E, 0x0104, 0x8101,
    0x8303, 0x0306, 0x030C, 0x8309, 0x0318, 0x831D, 0x8317, 0x0312,
    0x0330, 0x8335, 0x833F, 0x033A, 0x832B, 0x032E, 0x0324, 0x8321,
    0x0360, 0x8365, 0x836F, 0x036A, 0x837B, 0x037E, 0x0374, 0x8371,
    0x8353, 0x0356, 0x035C, 0x8359, 0x0348, 0x834D, 0x8347, 0x0342,
    0x03C0, 0x83C5, 0x83CF, 0x03CA, 0x83DB, 0x03DE, 0x03D4, 0x83D1,
    0x83F3, 0x03F6, 0x03FC, 0x83F9, 0x03E8, 0x83ED, 0x83E7, 0x03E2,
    0x83A3, 0x03A6, 0x03AC, 0x83A9, 0x03B8, 0x83BD, 0x83B7, 0x03B2,
    0x0390, 0x8395, 0x839F, 0x039A, 0x838B, 0x038E, 0x0384, 0x8381,
    0x0280, 0x8285, 0x828F, 0x028A, 0x829B, 0x029E, 0x0294, 0x8291,
    0x82B3, 0x02B6, 0x02BC, 0x82B9, 0x02A8, 0x82AD, 0x82A7, 0x02A2,
    0x82E3, 0x02E6, 0x02EC, 0x82E9, 0x02F8, 0x82FD, 0x82F7, 0x02F2,
    0x02D0, 0x82D5, 0x82DF, 0x02DA, 0x82CB, 0x02CE, 0x02C4, 0x82C1,
    0x8243, 0x0246, 0x024C, 0x8249, 0x0258, 0x825D, 0x8257, 0x0252,
    0x0270, 0x8275, 0x827F, 0x027A, 0x826B, 0x026E, 0x0264, 0x8261,
    0x0220, 0x8225, 0x822F, 0x022A, 0x823B, 0x023E, 0x0234, 0x8231,
    0x8213, 0x0216, 0x021C, 0x8219, 0x0208, 0x820D, 0x8207, 0x0202
};

static DRFLAC_INLINE drflac_uint8 drflac_crc8_byte(drflac_uint8 crc, drflac_uint8 data)
{
    return drflac__crc8_table[crc ^ data];
}

static DRFLAC_INLINE drflac_uint8 drflac_crc8(drflac_uint8 crc, drflac_uint32 data, drflac_uint32 count)
{

#ifdef DR_FLAC_NO_CRC
    (void)crc;
    (void)data;
    (void)count;
    drflac_assert(count <= 32);
    return 0;
#else
#if 0
    /* REFERENCE (use of this implementation requires an explicit flush by doing "drflac_crc8(crc, 0, 8);") */
    drflac_uint8 p = 0x07;
    for (int i = count-1; i >= 0; --i)
    {
       drflac_uint8 bit = (data & (1 << i)) >> i;
       if (crc & 0x80)
          crc = ((crc << 1) | bit) ^ p;
       else
          crc = ((crc << 1) | bit);
    }
    return crc;
#else
    static drflac_uint64 leftoverDataMaskTable[8] = {
        0x00, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F
    };
    drflac_uint32 wholeBytes = count >> 3;
    drflac_uint32 leftoverBits = count - (wholeBytes*8);
    drflac_uint64 leftoverDataMask = leftoverDataMaskTable[leftoverBits];
    drflac_assert(count <= 32);

    switch (wholeBytes)
    {
        case 4: crc = drflac_crc8_byte(crc, (drflac_uint8)((data & (0xFF000000UL << leftoverBits)) >> (24 + leftoverBits)));
        case 3: crc = drflac_crc8_byte(crc, (drflac_uint8)((data & (0x00FF0000UL << leftoverBits)) >> (16 + leftoverBits)));
        case 2: crc = drflac_crc8_byte(crc, (drflac_uint8)((data & (0x0000FF00UL << leftoverBits)) >> ( 8 + leftoverBits)));
        case 1: crc = drflac_crc8_byte(crc, (drflac_uint8)((data & (0x000000FFUL << leftoverBits)) >> ( 0 + leftoverBits)));
        case 0: if (leftoverBits > 0) crc = (crc << leftoverBits) ^ drflac__crc8_table[(crc >> (8 - leftoverBits)) ^ (data & leftoverDataMask)];
    }
    return crc;
#endif
#endif
}

static DRFLAC_INLINE drflac_uint16 drflac_crc16_byte(drflac_uint16 crc, drflac_uint8 data)
{
    return (crc << 8) ^ drflac__crc16_table[(drflac_uint8)(crc >> 8) ^ data];
}

static DRFLAC_INLINE drflac_uint16 drflac_crc16_bytes(drflac_uint16 crc, drflac_cache_t data, drflac_uint32 byteCount)
{
    switch (byteCount)
    {
#ifdef DRFLAC_64BIT
    case 8: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >> 56) & 0xFF));
    case 7: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >> 48) & 0xFF));
    case 6: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >> 40) & 0xFF));
    case 5: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >> 32) & 0xFF));
#endif
    case 4: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >> 24) & 0xFF));
    case 3: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >> 16) & 0xFF));
    case 2: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >>  8) & 0xFF));
    case 1: crc = drflac_crc16_byte(crc, (drflac_uint8)((data >>  0) & 0xFF));
    }

    return crc;
}

static DRFLAC_INLINE drflac_uint16 drflac_crc16__32bit(drflac_uint16 crc, drflac_uint32 data, drflac_uint32 count)
{

#ifdef DR_FLAC_NO_CRC
    (void)crc;
    (void)data;
    (void)count;
    drflac_assert(count <= 64);
    return 0;
#else
#if 0
    /* REFERENCE (use of this implementation requires an explicit flush by doing "drflac_crc16(crc, 0, 16);") */
    drflac_uint16 p = 0x8005;
    for (int i = count-1; i >= 0; --i)
    {
       drflac_uint16 bit = (data & (1ULL << i)) >> i;
       if (r & 0x8000)
          r = ((r << 1) | bit) ^ p;
       else
          r = ((r << 1) | bit);
    }

    return crc;
#else
    drflac_uint32 wholeBytes = count >> 3;
    drflac_uint32 leftoverBits = count - (wholeBytes*8);

    static drflac_uint64 leftoverDataMaskTable[8] = {
        0x00, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F
    };
    drflac_uint64 leftoverDataMask = leftoverDataMaskTable[leftoverBits];

    drflac_assert(count <= 64);

    switch (wholeBytes)
    {
        default:
        case 4: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & (0xFF000000UL << leftoverBits)) >> (24 + leftoverBits)));
        case 3: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & (0x00FF0000UL << leftoverBits)) >> (16 + leftoverBits)));
        case 2: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & (0x0000FF00UL << leftoverBits)) >> ( 8 + leftoverBits)));
        case 1: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & (0x000000FFUL << leftoverBits)) >> ( 0 + leftoverBits)));
        case 0: if (leftoverBits > 0) crc = (crc << leftoverBits) ^ drflac__crc16_table[(crc >> (16 - leftoverBits)) ^ (data & leftoverDataMask)];
    }
    return crc;
#endif
#endif
}

static DRFLAC_INLINE drflac_uint16 drflac_crc16__64bit(drflac_uint16 crc, drflac_uint64 data, drflac_uint32 count)
{

#ifdef DR_FLAC_NO_CRC
    (void)crc;
    (void)data;
    (void)count;
    drflac_assert(count <= 64);
    return 0;
#else
    drflac_uint32 wholeBytes = count >> 3;
    drflac_uint32 leftoverBits = count - (wholeBytes*8);

    static drflac_uint64 leftoverDataMaskTable[8] = {
        0x00, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F
    };
    drflac_uint64 leftoverDataMask = leftoverDataMaskTable[leftoverBits];

    drflac_assert(count <= 64);

    switch (wholeBytes)
    {
        default:
        case 8: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0xFF00000000000000 << leftoverBits)) >> (56 + leftoverBits)));
        case 7: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x00FF000000000000 << leftoverBits)) >> (48 + leftoverBits)));
        case 6: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x0000FF0000000000 << leftoverBits)) >> (40 + leftoverBits)));
        case 5: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x000000FF00000000 << leftoverBits)) >> (32 + leftoverBits)));
        case 4: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x00000000FF000000 << leftoverBits)) >> (24 + leftoverBits)));
        case 3: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x0000000000FF0000 << leftoverBits)) >> (16 + leftoverBits)));
        case 2: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x000000000000FF00 << leftoverBits)) >> ( 8 + leftoverBits)));
        case 1: crc = drflac_crc16_byte(crc, (drflac_uint8)((data & ((drflac_uint64)0x00000000000000FF << leftoverBits)) >> ( 0 + leftoverBits)));
        case 0: if (leftoverBits > 0) crc = (crc << leftoverBits) ^ drflac__crc16_table[(crc >> (16 - leftoverBits)) ^ (data & leftoverDataMask)];
    }
    return crc;
#endif
}


static DRFLAC_INLINE drflac_uint16 drflac_crc16(drflac_uint16 crc, drflac_cache_t data, drflac_uint32 count)
{
#ifdef DRFLAC_64BIT
    return drflac_crc16__64bit(crc, data, count);
#else
    return drflac_crc16__32bit(crc, data, count);
#endif
}


#ifdef DRFLAC_64BIT
#define drflac__be2host__cache_line drflac__be2host_64
#else
#define drflac__be2host__cache_line drflac__be2host_32
#endif

/* BIT READING ATTEMPT #2
 *
 * This uses a 32- or 64-bit bit-shifted cache - as bits are read, the cache is shifted such that the first valid bit is sitting
 * on the most significant bit. It uses the notion of an L1 and L2 cache (borrowed from CPU architecture), where the L1 cache
 * is a 32- or 64-bit unsigned integer (depending on whether or not a 32- or 64-bit build is being compiled) and the L2 is an
 * array of "cache lines", with each cache line being the same size as the L1. The L2 is a buffer of about 4KB and is where data
 * from onRead() is read into.
 */
#define DRFLAC_CACHE_L1_SIZE_BYTES(bs)                  (sizeof((bs)->cache))
#define DRFLAC_CACHE_L1_SIZE_BITS(bs)                   (sizeof((bs)->cache)*8)
#define DRFLAC_CACHE_L1_BITS_REMAINING(bs)              (DRFLAC_CACHE_L1_SIZE_BITS(bs) - ((bs)->consumedBits))
#ifdef DRFLAC_64BIT
#define DRFLAC_CACHE_L1_SELECTION_MASK(_bitCount)       (~(((drflac_uint64)-1LL) >> (_bitCount)))
#else
#define DRFLAC_CACHE_L1_SELECTION_MASK(_bitCount)       (~(((drflac_uint32)-1) >> (_bitCount)))
#endif
#define DRFLAC_CACHE_L1_SELECTION_SHIFT(bs, _bitCount)  (DRFLAC_CACHE_L1_SIZE_BITS(bs) - (_bitCount))
#define DRFLAC_CACHE_L1_SELECT(bs, _bitCount)           (((bs)->cache) & DRFLAC_CACHE_L1_SELECTION_MASK(_bitCount))
#define DRFLAC_CACHE_L1_SELECT_AND_SHIFT(bs, _bitCount) (DRFLAC_CACHE_L1_SELECT((bs), _bitCount) >> DRFLAC_CACHE_L1_SELECTION_SHIFT((bs), _bitCount))
#define DRFLAC_CACHE_L2_SIZE_BYTES(bs)                  (sizeof((bs)->cacheL2))
#define DRFLAC_CACHE_L2_LINE_COUNT(bs)                  (DRFLAC_CACHE_L2_SIZE_BYTES(bs) / sizeof((bs)->cacheL2[0]))
#define DRFLAC_CACHE_L2_LINES_REMAINING(bs)             (DRFLAC_CACHE_L2_LINE_COUNT(bs) - (bs)->nextL2Line)


#ifndef DR_FLAC_NO_CRC
static DRFLAC_INLINE void drflac__reset_crc16(drflac_bs* bs)
{
    bs->crc16 = 0;
    bs->crc16CacheIgnoredBytes = bs->consumedBits >> 3;
}

static DRFLAC_INLINE void drflac__update_crc16(drflac_bs* bs)
{
    bs->crc16 = drflac_crc16_bytes(bs->crc16, bs->crc16Cache, DRFLAC_CACHE_L1_SIZE_BYTES(bs) - bs->crc16CacheIgnoredBytes);
    bs->crc16CacheIgnoredBytes = 0;
}

static DRFLAC_INLINE drflac_uint16 drflac__flush_crc16(drflac_bs* bs)
{
    /* We should never be flushing in a situation where we are not aligned on a byte boundary. */
    drflac_assert((DRFLAC_CACHE_L1_BITS_REMAINING(bs) & 7) == 0);

    /* The bits that were read from the L1 cache need to be accumulated. The number of bytes needing to be accumulated is determined
     * by the number of bits that have been consumed. */
    if (DRFLAC_CACHE_L1_BITS_REMAINING(bs) == 0)
        drflac__update_crc16(bs);
    else
    {
        /* We only accumulate the consumed bits. */
        bs->crc16 = drflac_crc16_bytes(bs->crc16, bs->crc16Cache >> DRFLAC_CACHE_L1_BITS_REMAINING(bs), (bs->consumedBits >> 3) - bs->crc16CacheIgnoredBytes);

        /* The bits that we just accumulated should never be accumulated again. We need to keep track of how many bytes were accumulated
         * so we can handle that later. */
        bs->crc16CacheIgnoredBytes = bs->consumedBits >> 3;
    }

    return bs->crc16;
}
#endif

static DRFLAC_INLINE drflac_bool32 drflac__reload_l1_cache_from_l2(drflac_bs* bs)
{
   size_t alignedL1LineCount;
   size_t bytesRead;
   /* Fast path. Try loading straight from L2. */
   if (bs->nextL2Line < DRFLAC_CACHE_L2_LINE_COUNT(bs))
   {
      bs->cache = bs->cacheL2[bs->nextL2Line++];
      return DRFLAC_TRUE;
   }

   /* If we get here it means we've run out of data in the L2 cache. We'll need to fetch more from the client, if there's
    * any left. */
   if (bs->unalignedByteCount > 0)
      return DRFLAC_FALSE;   /* If we have any unaligned bytes it means there's no more aligned bytes left in the client. */

   bytesRead = bs->onRead(bs->pUserData, bs->cacheL2, DRFLAC_CACHE_L2_SIZE_BYTES(bs));

   bs->nextL2Line = 0;
   if (bytesRead == DRFLAC_CACHE_L2_SIZE_BYTES(bs))
   {
      bs->cache = bs->cacheL2[bs->nextL2Line++];
      return DRFLAC_TRUE;
   }


   /* If we get here it means we were unable to retrieve enough data to fill the entire L2 cache. It probably
    * means we've just reached the end of the file. We need to move the valid data down to the end of the buffer
    * and adjust the index of the next line accordingly. Also keep in mind that the L2 cache must be aligned to
    * the size of the L1 so we'll need to seek backwards by any misaligned bytes.
    */
   alignedL1LineCount = bytesRead / DRFLAC_CACHE_L1_SIZE_BYTES(bs);

   /* We need to keep track of any unaligned bytes for later use. */
   bs->unalignedByteCount = bytesRead - (alignedL1LineCount * DRFLAC_CACHE_L1_SIZE_BYTES(bs));
   if (bs->unalignedByteCount > 0)
      bs->unalignedCache = bs->cacheL2[alignedL1LineCount];

   if (alignedL1LineCount > 0)
   {
      size_t i;
      size_t offset = DRFLAC_CACHE_L2_LINE_COUNT(bs) - alignedL1LineCount;
      for (i = alignedL1LineCount; i > 0; --i)
         bs->cacheL2[i-1 + offset] = bs->cacheL2[i-1];

      bs->nextL2Line = (drflac_uint32)offset;
      bs->cache = bs->cacheL2[bs->nextL2Line++];
      return DRFLAC_TRUE;
   }

   /* If we get into this branch it means we weren't able to load any L1-aligned data. */
   bs->nextL2Line = DRFLAC_CACHE_L2_LINE_COUNT(bs);
   return DRFLAC_FALSE;
}

static drflac_bool32 drflac__reload_cache(drflac_bs* bs)
{
   size_t bytesRead;

#ifndef DR_FLAC_NO_CRC
    drflac__update_crc16(bs);
#endif

    /* Fast path. Try just moving the next value in the L2 cache to the L1 cache. */
    if (drflac__reload_l1_cache_from_l2(bs))
    {
        bs->cache = drflac__be2host__cache_line(bs->cache);
        bs->consumedBits = 0;
#ifndef DR_FLAC_NO_CRC
        bs->crc16Cache = bs->cache;
#endif
        return DRFLAC_TRUE;
    }

    /* Slow path. */

    /* If we get here it means we have failed to load the L1 cache from the L2. Likely we've just reached the end of the stream and the last
     * few bytes did not meet the alignment requirements for the L2 cache. In this case we need to fall back to a slower path and read the
     * data from the unaligned cache. */
    bytesRead = bs->unalignedByteCount;
    if (bytesRead == 0)
        return DRFLAC_FALSE;

    drflac_assert(bytesRead < DRFLAC_CACHE_L1_SIZE_BYTES(bs));
    bs->consumedBits = (drflac_uint32)(DRFLAC_CACHE_L1_SIZE_BYTES(bs) - bytesRead) * 8;

    bs->cache = drflac__be2host__cache_line(bs->unalignedCache);
    bs->cache &= DRFLAC_CACHE_L1_SELECTION_MASK(DRFLAC_CACHE_L1_SIZE_BITS(bs) - bs->consumedBits);    /* <-- Make sure the consumed bits are always set to zero. Other parts of the library depend on this property. */
    bs->unalignedByteCount = 0;     /* <-- At this point the unaligned bytes have been moved into the cache and we thus have no more unaligned bytes. */

#ifndef DR_FLAC_NO_CRC
    bs->crc16Cache = bs->cache >> bs->consumedBits;
    bs->crc16CacheIgnoredBytes = bs->consumedBits >> 3;
#endif
    return DRFLAC_TRUE;
}

static void drflac__reset_cache(drflac_bs* bs)
{
    bs->nextL2Line   = DRFLAC_CACHE_L2_LINE_COUNT(bs);  /* <-- This clears the L2 cache. */
    bs->consumedBits = DRFLAC_CACHE_L1_SIZE_BITS(bs);   /* <-- This clears the L1 cache. */
    bs->cache = 0;
    bs->unalignedByteCount = 0;                         /* <-- This clears the trailing unaligned bytes. */
    bs->unalignedCache = 0;

#ifndef DR_FLAC_NO_CRC
    bs->crc16Cache = 0;
    bs->crc16CacheIgnoredBytes = 0;
#endif
}


static DRFLAC_INLINE drflac_bool32 drflac__read_uint32(drflac_bs* bs, unsigned int bitCount, drflac_uint32* pResultOut)
{
    drflac_assert(bs != NULL);
    drflac_assert(pResultOut != NULL);
    drflac_assert(bitCount > 0);
    drflac_assert(bitCount <= 32);

    if (bs->consumedBits == DRFLAC_CACHE_L1_SIZE_BITS(bs))
    {
        if (!drflac__reload_cache(bs))
            return DRFLAC_FALSE;
    }

    if (bitCount <= DRFLAC_CACHE_L1_BITS_REMAINING(bs))
    {
        if (bitCount < DRFLAC_CACHE_L1_SIZE_BITS(bs))
        {
            *pResultOut = DRFLAC_CACHE_L1_SELECT_AND_SHIFT(bs, bitCount);
            bs->consumedBits += bitCount;
            bs->cache <<= bitCount;
        } else {
            *pResultOut = (drflac_uint32)bs->cache;
            bs->consumedBits = DRFLAC_CACHE_L1_SIZE_BITS(bs);
            bs->cache = 0;
        }
        return DRFLAC_TRUE;
    } else {
        /* It straddles the cached data. It will never cover more than the next chunk. We just read the number in two parts and combine them. */
        drflac_uint32 bitCountHi = DRFLAC_CACHE_L1_BITS_REMAINING(bs);
        drflac_uint32 bitCountLo = bitCount - bitCountHi;
        drflac_uint32 resultHi = DRFLAC_CACHE_L1_SELECT_AND_SHIFT(bs, bitCountHi);

        if (!drflac__reload_cache(bs))
            return DRFLAC_FALSE;

        *pResultOut = (resultHi << bitCountLo) | DRFLAC_CACHE_L1_SELECT_AND_SHIFT(bs, bitCountLo);
        bs->consumedBits += bitCountLo;
        bs->cache <<= bitCountLo;
        return DRFLAC_TRUE;
    }
}

static drflac_bool32 drflac__read_int32(drflac_bs* bs, unsigned int bitCount, drflac_int32* pResult)
{
   drflac_uint32 result;
   drflac_uint32 signbit;

   drflac_assert(bs != NULL);
   drflac_assert(pResult != NULL);
   drflac_assert(bitCount > 0);
   drflac_assert(bitCount <= 32);

   if (!drflac__read_uint32(bs, bitCount, &result))
      return DRFLAC_FALSE;

   signbit = ((result >> (bitCount-1)) & 0x01);
   result |= (~signbit + 1) << bitCount;

   *pResult = (drflac_int32)result;
   return DRFLAC_TRUE;
}

static drflac_bool32 drflac__read_uint64(drflac_bs* bs, unsigned int bitCount, drflac_uint64* pResultOut)
{
    drflac_uint32 resultHi;
    drflac_uint32 resultLo;

    drflac_assert(bitCount <= 64);
    drflac_assert(bitCount >  32);

    if (!drflac__read_uint32(bs, bitCount - 32, &resultHi))
        return DRFLAC_FALSE;

    if (!drflac__read_uint32(bs, 32, &resultLo))
        return DRFLAC_FALSE;

    *pResultOut = (((drflac_uint64)resultHi) << 32) | ((drflac_uint64)resultLo);
    return DRFLAC_TRUE;
}

/* Function below is unused, but leaving it here in case I need to quickly add it again. */
#if 0
static drflac_bool32 drflac__read_int64(drflac_bs* bs, unsigned int bitCount, drflac_int64* pResultOut)
{
    drflac_assert(bitCount <= 64);

    drflac_uint64 result;
    if (!drflac__read_uint64(bs, bitCount, &result))
        return DRFLAC_FALSE;

    drflac_uint64 signbit = ((result >> (bitCount-1)) & 0x01);
    result |= (~signbit + 1) << bitCount;

    *pResultOut = (drflac_int64)result;
    return DRFLAC_TRUE;
}
#endif

static drflac_bool32 drflac__read_uint16(drflac_bs* bs, unsigned int bitCount, drflac_uint16* pResult)
{
    drflac_uint32 result;

    drflac_assert(bs != NULL);
    drflac_assert(pResult != NULL);
    drflac_assert(bitCount > 0);
    drflac_assert(bitCount <= 16);

    if (!drflac__read_uint32(bs, bitCount, &result))
        return DRFLAC_FALSE;

    *pResult = (drflac_uint16)result;
    return DRFLAC_TRUE;
}

#if 0
static drflac_bool32 drflac__read_int16(drflac_bs* bs, unsigned int bitCount, drflac_int16* pResult)
{
    drflac_int32 result;

    drflac_assert(bs != NULL);
    drflac_assert(pResult != NULL);
    drflac_assert(bitCount > 0);
    drflac_assert(bitCount <= 16);

    if (!drflac__read_int32(bs, bitCount, &result))
        return DRFLAC_FALSE;

    *pResult = (drflac_int16)result;
    return DRFLAC_TRUE;
}
#endif

static drflac_bool32 drflac__read_uint8(drflac_bs* bs, unsigned int bitCount, drflac_uint8* pResult)
{
    drflac_uint32 result;

    drflac_assert(bs != NULL);
    drflac_assert(pResult != NULL);
    drflac_assert(bitCount > 0);
    drflac_assert(bitCount <= 8);

    if (!drflac__read_uint32(bs, bitCount, &result))
        return DRFLAC_FALSE;

    *pResult = (drflac_uint8)result;
    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__read_int8(drflac_bs* bs, unsigned int bitCount, drflac_int8* pResult)
{
    drflac_int32 result;

    drflac_assert(bs != NULL);
    drflac_assert(pResult != NULL);
    drflac_assert(bitCount > 0);
    drflac_assert(bitCount <= 8);

    if (!drflac__read_int32(bs, bitCount, &result))
        return DRFLAC_FALSE;

    *pResult = (drflac_int8)result;
    return DRFLAC_TRUE;
}


static drflac_bool32 drflac__seek_bits(drflac_bs* bs, size_t bitsToSeek)
{
   if (bitsToSeek <= DRFLAC_CACHE_L1_BITS_REMAINING(bs))
   {
      bs->consumedBits += (drflac_uint32)bitsToSeek;
      bs->cache <<= bitsToSeek;
      return DRFLAC_TRUE;
   }

   /* It straddles the cached data. This function isn't called too frequently so I'm favouring simplicity here. */
   bitsToSeek       -= DRFLAC_CACHE_L1_BITS_REMAINING(bs);
   bs->consumedBits += DRFLAC_CACHE_L1_BITS_REMAINING(bs);
   bs->cache         = 0;

   /* Simple case. Seek in groups of the same number as bits that fit within a cache line. */
#ifdef DRFLAC_64BIT
   while (bitsToSeek >= DRFLAC_CACHE_L1_SIZE_BITS(bs))
   {
      drflac_uint64 bin;
      if (!drflac__read_uint64(bs, DRFLAC_CACHE_L1_SIZE_BITS(bs), &bin))
         return DRFLAC_FALSE;
      bitsToSeek -= DRFLAC_CACHE_L1_SIZE_BITS(bs);
   }
#else
   while (bitsToSeek >= DRFLAC_CACHE_L1_SIZE_BITS(bs))
   {
      drflac_uint32 bin;
      if (!drflac__read_uint32(bs, DRFLAC_CACHE_L1_SIZE_BITS(bs), &bin))
         return DRFLAC_FALSE;
      bitsToSeek -= DRFLAC_CACHE_L1_SIZE_BITS(bs);
   }
#endif

   /* Whole leftover bytes. */
   while (bitsToSeek >= 8)
   {
      drflac_uint8 bin;
      if (!drflac__read_uint8(bs, 8, &bin))
         return DRFLAC_FALSE;
      bitsToSeek -= 8;
   }

   /* Leftover bits. */
   if (bitsToSeek > 0)
   {
      drflac_uint8 bin;
      if (!drflac__read_uint8(bs, (drflac_uint32)bitsToSeek, &bin))
         return DRFLAC_FALSE;
      bitsToSeek = 0; /* <-- Necessary for the assert below. */
   }

   drflac_assert(bitsToSeek == 0);
   return DRFLAC_TRUE;
}


/* This function moves the bit streamer to the first bit after the sync code (bit 15 of the of the frame header). It will also update the CRC-16. */
static drflac_bool32 drflac__find_and_seek_to_next_sync_code(drflac_bs* bs)
{
    drflac_assert(bs != NULL);

    /* The sync code is always aligned to 8 bits. This is convenient for us because it means we can do byte-aligned movements. The first
     * thing to do is align to the next byte. */
    if (!drflac__seek_bits(bs, DRFLAC_CACHE_L1_BITS_REMAINING(bs) & 7))
        return DRFLAC_FALSE;

    for (;;)
    {
       drflac_uint8 hi;

#ifndef DR_FLAC_NO_CRC
       drflac__reset_crc16(bs);
#endif

       if (!drflac__read_uint8(bs, 8, &hi))
          return DRFLAC_FALSE;

       if (hi == 0xFF)
       {
          drflac_uint8 lo;
          if (!drflac__read_uint8(bs, 6, &lo))
             return DRFLAC_FALSE;

          if (lo == 0x3E)
             return DRFLAC_TRUE;

          if (!drflac__seek_bits(bs, DRFLAC_CACHE_L1_BITS_REMAINING(bs) & 7))
             return DRFLAC_FALSE;
       }
    }

#if 0
    /* Should never get here. */
    return DRFLAC_FALSE;
#endif
}


#if !defined(DR_FLAC_NO_SIMD) && defined(DRFLAC_HAS_LZCNT_INTRINSIC)
#define DRFLAC_IMPLEMENT_CLZ_LZCNT
#endif
#if  defined(_MSC_VER) && _MSC_VER >= 1400 && (defined(DRFLAC_X64) || defined(DRFLAC_X86))
#define DRFLAC_IMPLEMENT_CLZ_MSVC
#endif

static DRFLAC_INLINE drflac_uint32 drflac__clz_software(drflac_cache_t x)
{
    static drflac_uint32 clz_table_4[] = {
        0,
        4,
        3, 3,
        2, 2, 2, 2,
        1, 1, 1, 1, 1, 1, 1, 1
    };
    drflac_uint32 n = clz_table_4[x >> (sizeof(x)*8 - 4)];

    if (n == 0)
    {
#ifdef DRFLAC_64BIT
        if ((x & 0xFFFFFFFF00000000ULL) == 0) { n  = 32; x <<= 32; }
        if ((x & 0xFFFF000000000000ULL) == 0) { n += 16; x <<= 16; }
        if ((x & 0xFF00000000000000ULL) == 0) { n += 8;  x <<= 8;  }
        if ((x & 0xF000000000000000ULL) == 0) { n += 4;  x <<= 4;  }
#else
        if ((x & 0xFFFF0000) == 0) { n  = 16; x <<= 16; }
        if ((x & 0xFF000000) == 0) { n += 8;  x <<= 8;  }
        if ((x & 0xF0000000) == 0) { n += 4;  x <<= 4;  }
#endif
        n += clz_table_4[x >> (sizeof(x)*8 - 4)];
    }

    return n - 1;
}

#ifdef DRFLAC_IMPLEMENT_CLZ_LZCNT
static DRFLAC_INLINE drflac_bool32 drflac__is_lzcnt_supported()
{
    /* If the compiler itself does not support the intrinsic then we'll need to return false. */
#ifdef DRFLAC_HAS_LZCNT_INTRINSIC
    return drflac__gIsLZCNTSupported;
#else
    return DRFLAC_FALSE;
#endif
}

static DRFLAC_INLINE drflac_uint32 drflac__clz_lzcnt(drflac_cache_t x)
{
#if defined(_MSC_VER) && !defined(__clang__)
#ifdef DRFLAC_64BIT
   return (drflac_uint32)__lzcnt64(x);
#else
   return (drflac_uint32)__lzcnt(x);
#endif
#else
#if defined(__GNUC__) || defined(__clang__)
#ifdef DRFLAC_64BIT
   return (drflac_uint32)__builtin_clzll((unsigned long long)x);
#else
   return (drflac_uint32)__builtin_clzl((unsigned long)x);
#endif
#else
   /* Unsupported compiler. */
#error "This compiler does not support the lzcnt intrinsic."
#endif
#endif
}
#endif

#ifdef DRFLAC_IMPLEMENT_CLZ_MSVC
static DRFLAC_INLINE drflac_uint32 drflac__clz_msvc(drflac_cache_t x)
{
   drflac_uint32 n;
#ifdef DRFLAC_64BIT
   _BitScanReverse64((unsigned long*)&n, x);
#else
   _BitScanReverse((unsigned long*)&n, x);
#endif
   return sizeof(x)*8 - n - 1;
}
#endif

static DRFLAC_INLINE drflac_uint32 drflac__clz(drflac_cache_t x)
{
   /* This function assumes at least one bit is set. Checking for 0 needs to be done at a higher level, outside this function. */
#ifdef DRFLAC_IMPLEMENT_CLZ_LZCNT
   if (drflac__is_lzcnt_supported())
      return drflac__clz_lzcnt(x);
#endif

#ifdef DRFLAC_IMPLEMENT_CLZ_MSVC
   return drflac__clz_msvc(x);
#else
   return drflac__clz_software(x);
#endif
}

static INLINE drflac_bool32 drflac__seek_past_next_set_bit(drflac_bs* bs, unsigned int* pOffsetOut)
{
   drflac_uint32 setBitOffsetPlus1;
   drflac_uint32 zeroCounter = 0;
   while (bs->cache == 0)
   {
      zeroCounter += (drflac_uint32)DRFLAC_CACHE_L1_BITS_REMAINING(bs);
      if (!drflac__reload_cache(bs))
         return DRFLAC_FALSE;
   }

   setBitOffsetPlus1 = drflac__clz(bs->cache);
   zeroCounter += setBitOffsetPlus1;
   setBitOffsetPlus1 += 1;

   bs->consumedBits += setBitOffsetPlus1;
   bs->cache <<= setBitOffsetPlus1;

   *pOffsetOut = zeroCounter + setBitOffsetPlus1 - 1;
   return DRFLAC_TRUE;
}



static drflac_bool32 drflac__seek_to_byte(drflac_bs* bs, drflac_uint64 offsetFromStart)
{
    drflac_assert(bs != NULL);
    drflac_assert(offsetFromStart > 0);

    /* Seeking from the start is not quite as trivial as it sounds because the onSeek callback takes a signed 32-bit integer (which
     * is intentional because it simplifies the implementation of the onSeek callbacks), however offsetFromStart is unsigned 64-bit.
     * To resolve we just need to do an initial seek from the start, and then a series of offset seeks to make up the remainder. */
    if (offsetFromStart > 0x7FFFFFFF)
    {
        drflac_uint64 bytesRemaining = offsetFromStart;
        if (!bs->onSeek(bs->pUserData, 0x7FFFFFFF, drflac_seek_origin_start))
            return DRFLAC_FALSE;
        bytesRemaining -= 0x7FFFFFFF;

        while (bytesRemaining > 0x7FFFFFFF)
        {
            if (!bs->onSeek(bs->pUserData, 0x7FFFFFFF, drflac_seek_origin_current))
                return DRFLAC_FALSE;
            bytesRemaining -= 0x7FFFFFFF;
        }

        if (bytesRemaining > 0)
        {
            if (!bs->onSeek(bs->pUserData, (int)bytesRemaining, drflac_seek_origin_current))
                return DRFLAC_FALSE;
        }
    }
    else
    {
       if (!bs->onSeek(bs->pUserData, (int)offsetFromStart, drflac_seek_origin_start))
          return DRFLAC_FALSE;
    }

    /* The cache should be reset to force a reload of fresh data from the client. */
    drflac__reset_cache(bs);
    return DRFLAC_TRUE;
}


static drflac_result drflac__read_utf8_coded_number(drflac_bs* bs, drflac_uint64* pNumberOut, drflac_uint8* pCRCOut)
{
   drflac_uint64 result;
   int i;
   int byteCount = 1;
   unsigned char utf8[7] = {0};
   drflac_uint8 crc;

   drflac_assert(bs != NULL);
   drflac_assert(pNumberOut != NULL);

   crc = *pCRCOut;

   if (!drflac__read_uint8(bs, 8, utf8))
   {
      *pNumberOut = 0;
      return DRFLAC_END_OF_STREAM;
   }
   crc = drflac_crc8(crc, utf8[0], 8);

   if ((utf8[0] & 0x80) == 0)
   {
      *pNumberOut = utf8[0];
      *pCRCOut = crc;
      return DRFLAC_SUCCESS;
   }

   if ((utf8[0] & 0xE0) == 0xC0)
      byteCount = 2;
   else if ((utf8[0] & 0xF0) == 0xE0)
      byteCount = 3;
   else if ((utf8[0] & 0xF8) == 0xF0)
      byteCount = 4;
   else if ((utf8[0] & 0xFC) == 0xF8)
      byteCount = 5;
   else if ((utf8[0] & 0xFE) == 0xFC)
      byteCount = 6;
   else if ((utf8[0] & 0xFF) == 0xFE)
      byteCount = 7;
   else
   {
      *pNumberOut = 0;
      return DRFLAC_CRC_MISMATCH;     /* Bad UTF-8 encoding. */
   }

   /* Read extra bytes. */
   drflac_assert(byteCount > 1);

   result = (drflac_uint64)(utf8[0] & (0xFF >> (byteCount + 1)));
   for (i = 1; i < byteCount; ++i)
   {
      if (!drflac__read_uint8(bs, 8, utf8 + i))
      {
         *pNumberOut = 0;
         return DRFLAC_END_OF_STREAM;
      }
      crc = drflac_crc8(crc, utf8[i], 8);

      result = (result << 6) | (utf8[i] & 0x3F);
   }

   *pNumberOut = result;
   *pCRCOut = crc;
   return DRFLAC_SUCCESS;
}




/* The next two functions are responsible for calculating the prediction.
 *
 * When the bits per sample is >16 we need to use 64-bit integer arithmetic because otherwise we'll run out of precision. It's
 * safe to assume this will be slower on 32-bit platforms so we use a more optimal solution when the bits per sample is <=16.
 */
static DRFLAC_INLINE drflac_int32 drflac__calculate_prediction_32(drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pDecodedSamples)
{
   drflac_int32 prediction = 0;

   drflac_assert(order <= 32);

   /* 32-bit version.

    * VC++ optimizes this to a single jmp. I've not yet verified this for other compilers. */

   switch (order)
   {
      case 32: prediction += coefficients[31] * pDecodedSamples[-32];
      case 31: prediction += coefficients[30] * pDecodedSamples[-31];
      case 30: prediction += coefficients[29] * pDecodedSamples[-30];
      case 29: prediction += coefficients[28] * pDecodedSamples[-29];
      case 28: prediction += coefficients[27] * pDecodedSamples[-28];
      case 27: prediction += coefficients[26] * pDecodedSamples[-27];
      case 26: prediction += coefficients[25] * pDecodedSamples[-26];
      case 25: prediction += coefficients[24] * pDecodedSamples[-25];
      case 24: prediction += coefficients[23] * pDecodedSamples[-24];
      case 23: prediction += coefficients[22] * pDecodedSamples[-23];
      case 22: prediction += coefficients[21] * pDecodedSamples[-22];
      case 21: prediction += coefficients[20] * pDecodedSamples[-21];
      case 20: prediction += coefficients[19] * pDecodedSamples[-20];
      case 19: prediction += coefficients[18] * pDecodedSamples[-19];
      case 18: prediction += coefficients[17] * pDecodedSamples[-18];
      case 17: prediction += coefficients[16] * pDecodedSamples[-17];
      case 16: prediction += coefficients[15] * pDecodedSamples[-16];
      case 15: prediction += coefficients[14] * pDecodedSamples[-15];
      case 14: prediction += coefficients[13] * pDecodedSamples[-14];
      case 13: prediction += coefficients[12] * pDecodedSamples[-13];
      case 12: prediction += coefficients[11] * pDecodedSamples[-12];
      case 11: prediction += coefficients[10] * pDecodedSamples[-11];
      case 10: prediction += coefficients[ 9] * pDecodedSamples[-10];
      case  9: prediction += coefficients[ 8] * pDecodedSamples[- 9];
      case  8: prediction += coefficients[ 7] * pDecodedSamples[- 8];
      case  7: prediction += coefficients[ 6] * pDecodedSamples[- 7];
      case  6: prediction += coefficients[ 5] * pDecodedSamples[- 6];
      case  5: prediction += coefficients[ 4] * pDecodedSamples[- 5];
      case  4: prediction += coefficients[ 3] * pDecodedSamples[- 4];
      case  3: prediction += coefficients[ 2] * pDecodedSamples[- 3];
      case  2: prediction += coefficients[ 1] * pDecodedSamples[- 2];
      case  1: prediction += coefficients[ 0] * pDecodedSamples[- 1];
   }

   return (drflac_int32)(prediction >> shift);
}

static DRFLAC_INLINE drflac_int32 drflac__calculate_prediction_64(drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pDecodedSamples)
{
    drflac_int64 prediction;
    drflac_assert(order <= 32);

    /* 64-bit version.

     * This method is faster on the 32-bit build when compiling with VC++. See note below.
     */

#ifndef DRFLAC_64BIT
    if (order == 8)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2] * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3] * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4] * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5] * (drflac_int64)pDecodedSamples[-6];
        prediction += coefficients[6] * (drflac_int64)pDecodedSamples[-7];
        prediction += coefficients[7] * (drflac_int64)pDecodedSamples[-8];
    }
    else if (order == 7)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2] * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3] * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4] * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5] * (drflac_int64)pDecodedSamples[-6];
        prediction += coefficients[6] * (drflac_int64)pDecodedSamples[-7];
    }
    else if (order == 3)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2] * (drflac_int64)pDecodedSamples[-3];
    }
    else if (order == 6)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2] * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3] * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4] * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5] * (drflac_int64)pDecodedSamples[-6];
    }
    else if (order == 5)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2] * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3] * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4] * (drflac_int64)pDecodedSamples[-5];
    }
    else if (order == 4)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2] * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3] * (drflac_int64)pDecodedSamples[-4];
    }
    else if (order == 12)
    {
        prediction  = coefficients[0]  * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1]  * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2]  * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3]  * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4]  * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5]  * (drflac_int64)pDecodedSamples[-6];
        prediction += coefficients[6]  * (drflac_int64)pDecodedSamples[-7];
        prediction += coefficients[7]  * (drflac_int64)pDecodedSamples[-8];
        prediction += coefficients[8]  * (drflac_int64)pDecodedSamples[-9];
        prediction += coefficients[9]  * (drflac_int64)pDecodedSamples[-10];
        prediction += coefficients[10] * (drflac_int64)pDecodedSamples[-11];
        prediction += coefficients[11] * (drflac_int64)pDecodedSamples[-12];
    }
    else if (order == 2)
    {
        prediction  = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1] * (drflac_int64)pDecodedSamples[-2];
    }
    else if (order == 1)
    {
        prediction = coefficients[0] * (drflac_int64)pDecodedSamples[-1];
    }
    else if (order == 10)
    {
        prediction  = coefficients[0]  * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1]  * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2]  * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3]  * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4]  * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5]  * (drflac_int64)pDecodedSamples[-6];
        prediction += coefficients[6]  * (drflac_int64)pDecodedSamples[-7];
        prediction += coefficients[7]  * (drflac_int64)pDecodedSamples[-8];
        prediction += coefficients[8]  * (drflac_int64)pDecodedSamples[-9];
        prediction += coefficients[9]  * (drflac_int64)pDecodedSamples[-10];
    }
    else if (order == 9)
    {
        prediction  = coefficients[0]  * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1]  * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2]  * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3]  * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4]  * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5]  * (drflac_int64)pDecodedSamples[-6];
        prediction += coefficients[6]  * (drflac_int64)pDecodedSamples[-7];
        prediction += coefficients[7]  * (drflac_int64)pDecodedSamples[-8];
        prediction += coefficients[8]  * (drflac_int64)pDecodedSamples[-9];
    }
    else if (order == 11)
    {
        prediction  = coefficients[0]  * (drflac_int64)pDecodedSamples[-1];
        prediction += coefficients[1]  * (drflac_int64)pDecodedSamples[-2];
        prediction += coefficients[2]  * (drflac_int64)pDecodedSamples[-3];
        prediction += coefficients[3]  * (drflac_int64)pDecodedSamples[-4];
        prediction += coefficients[4]  * (drflac_int64)pDecodedSamples[-5];
        prediction += coefficients[5]  * (drflac_int64)pDecodedSamples[-6];
        prediction += coefficients[6]  * (drflac_int64)pDecodedSamples[-7];
        prediction += coefficients[7]  * (drflac_int64)pDecodedSamples[-8];
        prediction += coefficients[8]  * (drflac_int64)pDecodedSamples[-9];
        prediction += coefficients[9]  * (drflac_int64)pDecodedSamples[-10];
        prediction += coefficients[10] * (drflac_int64)pDecodedSamples[-11];
    }
    else
    {
       int j;
       prediction = 0;
       for (j = 0; j < (int)order; ++j)
          prediction += coefficients[j] * (drflac_int64)pDecodedSamples[-j-1];
    }
#endif

    /* VC++ optimizes this to a single jmp instruction, but only the 64-bit build. The 32-bit build generates less efficient code for some
     * reason. The ugly version above is faster so we'll just switch between the two depending on the target platform. */
#ifdef DRFLAC_64BIT
    prediction = 0;

    switch (order)
    {
    case 32: prediction += coefficients[31] * (drflac_int64)pDecodedSamples[-32];
    case 31: prediction += coefficients[30] * (drflac_int64)pDecodedSamples[-31];
    case 30: prediction += coefficients[29] * (drflac_int64)pDecodedSamples[-30];
    case 29: prediction += coefficients[28] * (drflac_int64)pDecodedSamples[-29];
    case 28: prediction += coefficients[27] * (drflac_int64)pDecodedSamples[-28];
    case 27: prediction += coefficients[26] * (drflac_int64)pDecodedSamples[-27];
    case 26: prediction += coefficients[25] * (drflac_int64)pDecodedSamples[-26];
    case 25: prediction += coefficients[24] * (drflac_int64)pDecodedSamples[-25];
    case 24: prediction += coefficients[23] * (drflac_int64)pDecodedSamples[-24];
    case 23: prediction += coefficients[22] * (drflac_int64)pDecodedSamples[-23];
    case 22: prediction += coefficients[21] * (drflac_int64)pDecodedSamples[-22];
    case 21: prediction += coefficients[20] * (drflac_int64)pDecodedSamples[-21];
    case 20: prediction += coefficients[19] * (drflac_int64)pDecodedSamples[-20];
    case 19: prediction += coefficients[18] * (drflac_int64)pDecodedSamples[-19];
    case 18: prediction += coefficients[17] * (drflac_int64)pDecodedSamples[-18];
    case 17: prediction += coefficients[16] * (drflac_int64)pDecodedSamples[-17];
    case 16: prediction += coefficients[15] * (drflac_int64)pDecodedSamples[-16];
    case 15: prediction += coefficients[14] * (drflac_int64)pDecodedSamples[-15];
    case 14: prediction += coefficients[13] * (drflac_int64)pDecodedSamples[-14];
    case 13: prediction += coefficients[12] * (drflac_int64)pDecodedSamples[-13];
    case 12: prediction += coefficients[11] * (drflac_int64)pDecodedSamples[-12];
    case 11: prediction += coefficients[10] * (drflac_int64)pDecodedSamples[-11];
    case 10: prediction += coefficients[ 9] * (drflac_int64)pDecodedSamples[-10];
    case  9: prediction += coefficients[ 8] * (drflac_int64)pDecodedSamples[- 9];
    case  8: prediction += coefficients[ 7] * (drflac_int64)pDecodedSamples[- 8];
    case  7: prediction += coefficients[ 6] * (drflac_int64)pDecodedSamples[- 7];
    case  6: prediction += coefficients[ 5] * (drflac_int64)pDecodedSamples[- 6];
    case  5: prediction += coefficients[ 4] * (drflac_int64)pDecodedSamples[- 5];
    case  4: prediction += coefficients[ 3] * (drflac_int64)pDecodedSamples[- 4];
    case  3: prediction += coefficients[ 2] * (drflac_int64)pDecodedSamples[- 3];
    case  2: prediction += coefficients[ 1] * (drflac_int64)pDecodedSamples[- 2];
    case  1: prediction += coefficients[ 0] * (drflac_int64)pDecodedSamples[- 1];
    }
#endif

    return (drflac_int32)(prediction >> shift);
}

#if 0
/* Reference implementation for reading and decoding samples with residual. This is intentionally left unoptimized for the
 * sake of readability and should only be used as a reference. */
static drflac_bool32 drflac__decode_samples_with_residual__rice__reference(drflac_bs* bs, drflac_uint32 bitsPerSample, drflac_uint32 count, drflac_uint8 riceParam, drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pSamplesOut)
{
    drflac_assert(bs != NULL);
    drflac_assert(count > 0);
    drflac_assert(pSamplesOut != NULL);

    for (drflac_uint32 i = 0; i < count; ++i)
    {
        drflac_uint32 zeroCounter = 0;
        for (;;)
        {
            drflac_uint8 bit;
            if (!drflac__read_uint8(bs, 1, &bit))
                return DRFLAC_FALSE;

            if (bit == 0)
                zeroCounter += 1;
            else
                break;
        }

        drflac_uint32 decodedRice;
        if (riceParam > 0)
        {
            if (!drflac__read_uint32(bs, riceParam, &decodedRice))
                return DRFLAC_FALSE;
        }
        else
            decodedRice = 0;

        decodedRice |= (zeroCounter << riceParam);
        if ((decodedRice & 0x01))
            decodedRice = ~(decodedRice >> 1);
        else
            decodedRice =  (decodedRice >> 1);


        if (bitsPerSample > 16)
            pSamplesOut[i] = decodedRice + drflac__calculate_prediction_64(order, shift, coefficients, pSamplesOut + i);
        else
            pSamplesOut[i] = decodedRice + drflac__calculate_prediction_32(order, shift, coefficients, pSamplesOut + i);
    }

    return DRFLAC_TRUE;
}
#endif

#if 0
static drflac_bool32 drflac__read_rice_parts__reference(drflac_bs* bs, drflac_uint8 riceParam, drflac_uint32* pZeroCounterOut, drflac_uint32* pRiceParamPartOut)
{
    drflac_uint32 zeroCounter = 0;
    for (;;) {
        drflac_uint8 bit;
        if (!drflac__read_uint8(bs, 1, &bit))
            return DRFLAC_FALSE;

        if (bit == 0)
            zeroCounter += 1;
        else
            break;
    }

    drflac_uint32 decodedRice;
    if (riceParam > 0)
    {
        if (!drflac__read_uint32(bs, riceParam, &decodedRice))
            return DRFLAC_FALSE;
    }
    else
        decodedRice = 0;

    *pZeroCounterOut = zeroCounter;
    *pRiceParamPartOut = decodedRice;
    return DRFLAC_TRUE;
}
#endif

static DRFLAC_INLINE drflac_bool32 drflac__read_rice_parts(drflac_bs* bs, drflac_uint8 riceParam, drflac_uint32* pZeroCounterOut, drflac_uint32* pRiceParamPartOut)
{
   drflac_uint32 riceLength;
   drflac_uint32 riceParamPart     = 0;
   drflac_uint32 setBitOffsetPlus1;
   drflac_cache_t riceParamMask    = DRFLAC_CACHE_L1_SELECTION_MASK(riceParam);
   drflac_cache_t resultHiShift    = DRFLAC_CACHE_L1_SIZE_BITS(bs) - riceParam;
   drflac_uint32 zeroCounter       = 0;
   while (bs->cache == 0) {
      zeroCounter += (drflac_uint32)DRFLAC_CACHE_L1_BITS_REMAINING(bs);
      if (!drflac__reload_cache(bs))
         return DRFLAC_FALSE;
   }

   setBitOffsetPlus1 = drflac__clz(bs->cache);
   zeroCounter += setBitOffsetPlus1;
   setBitOffsetPlus1 += 1;

   riceLength = setBitOffsetPlus1 + riceParam;

   if (riceLength < DRFLAC_CACHE_L1_BITS_REMAINING(bs))
   {
      riceParamPart = (drflac_uint32)((bs->cache & (riceParamMask >> setBitOffsetPlus1)) >> (DRFLAC_CACHE_L1_SIZE_BITS(bs) - riceLength));

      bs->consumedBits += riceLength;
      bs->cache <<= riceLength;
   }
   else
   {
      drflac_uint32 bitCountLo;
      drflac_cache_t resultHi;

      bs->consumedBits += riceLength;
      if (setBitOffsetPlus1 < DRFLAC_CACHE_L1_SIZE_BITS(bs))
         bs->cache <<= setBitOffsetPlus1;

      /* It straddles the cached data. It will never cover more than the next chunk. We just read the number in two parts and combine them. */
      bitCountLo = bs->consumedBits - DRFLAC_CACHE_L1_SIZE_BITS(bs);
      resultHi   = bs->cache & riceParamMask;    /* <-- This mask is OK because all bits after the first bits are always zero. */

      if (bs->nextL2Line < DRFLAC_CACHE_L2_LINE_COUNT(bs)) {
#ifndef DR_FLAC_NO_CRC
         drflac__update_crc16(bs);
#endif
         bs->cache = drflac__be2host__cache_line(bs->cacheL2[bs->nextL2Line++]);
         bs->consumedBits = 0;
#ifndef DR_FLAC_NO_CRC
         bs->crc16Cache = bs->cache;
#endif
      } else {
         /* Slow path. We need to fetch more data from the client. */
         if (!drflac__reload_cache(bs)) {
            return DRFLAC_FALSE;
         }
      }

      riceParamPart = (drflac_uint32)((resultHi >> resultHiShift) | DRFLAC_CACHE_L1_SELECT_AND_SHIFT(bs, bitCountLo));

      bs->consumedBits += bitCountLo;
      bs->cache <<= bitCountLo;
   }

   *pZeroCounterOut = zeroCounter;
   *pRiceParamPartOut = riceParamPart;
   return DRFLAC_TRUE;
}


static drflac_bool32 drflac__decode_samples_with_residual__rice__simple(drflac_bs* bs, drflac_uint32 bitsPerSample, drflac_uint32 count, drflac_uint8 riceParam, drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pSamplesOut)
{
    drflac_uint32 zeroCountPart = 0;
    drflac_uint32 riceParamPart = 0;
    drflac_uint32 i             = 0;

    drflac_assert(bs != NULL);
    drflac_assert(count > 0);
    drflac_assert(pSamplesOut != NULL);

    while (i < count)
    {
       static drflac_uint32 t[2] = {0x00000000, 0xFFFFFFFF};
        /* Rice extraction. */
        if (!drflac__read_rice_parts(bs, riceParam, &zeroCountPart, &riceParamPart))
           return DRFLAC_FALSE;

        /* Rice reconstruction. */

        riceParamPart |= (zeroCountPart << riceParam);
        riceParamPart  = (riceParamPart >> 1) ^ t[riceParamPart & 0x01];
#if 0
        riceParamPart  = (riceParamPart >> 1) ^ (~(riceParamPart & 0x01) + 1);
#endif

        /* Sample reconstruction. */
        if (bitsPerSample > 16)
        {
            pSamplesOut[i] = riceParamPart + drflac__calculate_prediction_64(order, shift, coefficients, pSamplesOut + i);
        }
        else
        {
            pSamplesOut[i] = riceParamPart + drflac__calculate_prediction_32(order, shift, coefficients, pSamplesOut + i);
        }

        i += 1;
    }

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples_with_residual__rice(drflac_bs* bs, drflac_uint32 bitsPerSample, drflac_uint32 count, drflac_uint8 riceParam, drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pSamplesOut)
{
#if 0
    return drflac__decode_samples_with_residual__rice__reference(bs, bitsPerSample, count, riceParam, order, shift, coefficients, pSamplesOut);
#else
    return drflac__decode_samples_with_residual__rice__simple(bs, bitsPerSample, count, riceParam, order, shift, coefficients, pSamplesOut);
#endif
}

/* Reads and seeks past a string of residual values as Rice codes. The decoder should be sitting on the first bit of the Rice codes. */
static drflac_bool32 drflac__read_and_seek_residual__rice(drflac_bs* bs, drflac_uint32 count, drflac_uint8 riceParam)
{
   drflac_uint32 i;
    drflac_assert(bs != NULL);
    drflac_assert(count > 0);

    for (i = 0; i < count; ++i)
    {
       drflac_uint32 zeroCountPart;
       drflac_uint32 riceParamPart;
       if (!drflac__read_rice_parts(bs, riceParam, &zeroCountPart, &riceParamPart))
          return DRFLAC_FALSE;
    }

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples_with_residual__unencoded(drflac_bs* bs, drflac_uint32 bitsPerSample, drflac_uint32 count, drflac_uint8 unencodedBitsPerSample, drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pSamplesOut)
{
   unsigned int i;
   drflac_assert(bs != NULL);
   drflac_assert(count > 0);
   drflac_assert(unencodedBitsPerSample > 0 && unencodedBitsPerSample <= 32);
   drflac_assert(pSamplesOut != NULL);

   for (i = 0; i < count; ++i)
   {
      if (!drflac__read_int32(bs, unencodedBitsPerSample, pSamplesOut + i))
         return DRFLAC_FALSE;

      if (bitsPerSample > 16)
      {
         pSamplesOut[i] += drflac__calculate_prediction_64(order, shift, coefficients, pSamplesOut + i);
      }
      else
      {
         pSamplesOut[i] += drflac__calculate_prediction_32(order, shift, coefficients, pSamplesOut + i);
      }
   }

   return DRFLAC_TRUE;
}


/* Reads and decodes the residual for the sub-frame the decoder is currently sitting on. This function should be called
 * when the decoder is sitting at the very start of the RESIDUAL block. The first <order> residuals will be ignored. The
 * <blockSize> and <order> parameters are used to determine how many residual values need to be decoded. */
static drflac_bool32 drflac__decode_samples_with_residual(drflac_bs* bs, drflac_uint32 bitsPerSample, drflac_uint32 blockSize, drflac_uint32 order, drflac_int32 shift, const drflac_int32* coefficients, drflac_int32* pDecodedSamples)
{
   drflac_uint8 partitionOrder;
   drflac_uint8 residualMethod;
   drflac_uint32 samplesInPartition;
   drflac_uint32 partitionsRemaining;

   drflac_assert(bs != NULL);
   drflac_assert(blockSize != 0);
   drflac_assert(pDecodedSamples != NULL);       /* <-- Should we allow NULL, in which case we just seek past the residual rather than do a full decode? */

   if (!drflac__read_uint8(bs, 2, &residualMethod))
      return DRFLAC_FALSE;

   if (residualMethod != DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE && residualMethod != DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE2)
      return DRFLAC_FALSE;    /* Unknown or unsupported residual coding method. */

   /* Ignore the first <order> values. */
   pDecodedSamples += order;


   if (!drflac__read_uint8(bs, 4, &partitionOrder))
      return DRFLAC_FALSE;

   /* From the FLAC spec:
    *   The Rice partition order in a Rice-coded residual section must be less than or equal to 8. */
   if (partitionOrder > 8)
      return DRFLAC_FALSE;

   /* Validation check. */
   if ((blockSize / (1 << partitionOrder)) <= order)
      return DRFLAC_FALSE;

   samplesInPartition  = (blockSize / (1 << partitionOrder)) - order;
   partitionsRemaining = (1 << partitionOrder);

   for (;;)
   {
      drflac_uint8 riceParam = 0;
      if (residualMethod == DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE)
      {
         if (!drflac__read_uint8(bs, 4, &riceParam))
            return DRFLAC_FALSE;
         if (riceParam == 16)
            riceParam = 0xFF;
      }
      else if (residualMethod == DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE2)
      {
         if (!drflac__read_uint8(bs, 5, &riceParam))
            return DRFLAC_FALSE;
         if (riceParam == 32)
            riceParam = 0xFF;
      }

      if (riceParam != 0xFF)
      {
         if (!drflac__decode_samples_with_residual__rice(bs, bitsPerSample, samplesInPartition, riceParam, order, shift, coefficients, pDecodedSamples))
            return DRFLAC_FALSE;
      }
      else
      {
         unsigned char unencodedBitsPerSample = 0;
         if (!drflac__read_uint8(bs, 5, &unencodedBitsPerSample))
            return DRFLAC_FALSE;

         if (!drflac__decode_samples_with_residual__unencoded(bs, bitsPerSample, samplesInPartition, unencodedBitsPerSample, order, shift, coefficients, pDecodedSamples))
            return DRFLAC_FALSE;
      }

      pDecodedSamples += samplesInPartition;


      if (partitionsRemaining == 1)
         break;

      partitionsRemaining -= 1;

      if (partitionOrder != 0)
         samplesInPartition = blockSize / (1 << partitionOrder);
   }

   return DRFLAC_TRUE;
}

/* Reads and seeks past the residual for the sub-frame the decoder is currently sitting on. This function should be called
 * when the decoder is sitting at the very start of the RESIDUAL block. The first <order> residuals will be set to 0. The
 * <blockSize> and <order> parameters are used to determine how many residual values need to be decoded. */
static drflac_bool32 drflac__read_and_seek_residual(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 order)
{
   drflac_uint32 partitionsRemaining;
   drflac_uint32 samplesInPartition;
   drflac_uint8 partitionOrder;
   drflac_uint8 residualMethod;

   drflac_assert(bs != NULL);
   drflac_assert(blockSize != 0);

   if (!drflac__read_uint8(bs, 2, &residualMethod))
      return DRFLAC_FALSE;

   if (residualMethod != DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE && residualMethod != DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE2)
      return DRFLAC_FALSE;    /* Unknown or unsupported residual coding method. */

   if (!drflac__read_uint8(bs, 4, &partitionOrder))
      return DRFLAC_FALSE;

   samplesInPartition = (blockSize / (1 << partitionOrder)) - order;
   partitionsRemaining = (1 << partitionOrder);
   for (;;)
   {
      drflac_uint8 riceParam = 0;
      if (residualMethod == DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE)
      {
         if (!drflac__read_uint8(bs, 4, &riceParam))
            return DRFLAC_FALSE;
         if (riceParam == 16)
            riceParam = 0xFF;
      }
      else if (residualMethod == DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE2) {
         if (!drflac__read_uint8(bs, 5, &riceParam))
            return DRFLAC_FALSE;
         if (riceParam == 32)
            riceParam = 0xFF;
      }

      if (riceParam != 0xFF)
      {
         if (!drflac__read_and_seek_residual__rice(bs, samplesInPartition, riceParam))
            return DRFLAC_FALSE;
      }
      else
      {
         unsigned char unencodedBitsPerSample = 0;
         if (!drflac__read_uint8(bs, 5, &unencodedBitsPerSample))
            return DRFLAC_FALSE;

         if (!drflac__seek_bits(bs, unencodedBitsPerSample * samplesInPartition))
            return DRFLAC_FALSE;
      }

      if (partitionsRemaining == 1)
         break;

      partitionsRemaining -= 1;
      samplesInPartition = blockSize / (1 << partitionOrder);
   }

   return DRFLAC_TRUE;
}


static drflac_bool32 drflac__decode_samples__constant(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 bitsPerSample, drflac_int32* pDecodedSamples)
{
   drflac_uint32 i;
    /* Only a single sample needs to be decoded here. */
    drflac_int32 sample;
    if (!drflac__read_int32(bs, bitsPerSample, &sample))
        return DRFLAC_FALSE;

    /* We don't really need to expand this, but it does simplify the process of reading samples. If this becomes a performance issue (unlikely)
     * we'll want to look at a more efficient way. */
    for (i = 0; i < blockSize; ++i)
        pDecodedSamples[i] = sample;

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples__verbatim(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 bitsPerSample, drflac_int32* pDecodedSamples)
{
   drflac_uint32 i;
   for (i = 0; i < blockSize; ++i)
   {
      drflac_int32 sample;
      if (!drflac__read_int32(bs, bitsPerSample, &sample))
         return DRFLAC_FALSE;

      pDecodedSamples[i] = sample;
   }

   return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples__fixed(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 bitsPerSample, drflac_uint8 lpcOrder, drflac_int32* pDecodedSamples)
{
   drflac_uint32 i;
    drflac_int32 lpcCoefficientsTable[5][4] = {
        {0,  0, 0,  0},
        {1,  0, 0,  0},
        {2, -1, 0,  0},
        {3, -3, 1,  0},
        {4, -6, 4, -1}
    };

    /* Warm up samples and coefficients. */
    for (i = 0; i < lpcOrder; ++i)
    {
       drflac_int32 sample;
       if (!drflac__read_int32(bs, bitsPerSample, &sample))
          return DRFLAC_FALSE;

       pDecodedSamples[i] = sample;
    }


    if (!drflac__decode_samples_with_residual(bs, bitsPerSample, blockSize, lpcOrder, 0, lpcCoefficientsTable[lpcOrder], pDecodedSamples))
        return DRFLAC_FALSE;

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples__lpc(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 bitsPerSample, drflac_uint8 lpcOrder, drflac_int32* pDecodedSamples)
{
    drflac_uint8 i;
    drflac_uint8 lpcPrecision;
    drflac_int8 lpcShift;
    drflac_int32 coefficients[32];

    /* Warm up samples. */
    for (i = 0; i < lpcOrder; ++i)
    {
       drflac_int32 sample;
       if (!drflac__read_int32(bs, bitsPerSample, &sample))
          return DRFLAC_FALSE;

       pDecodedSamples[i] = sample;
    }

    if (!drflac__read_uint8(bs, 4, &lpcPrecision))
        return DRFLAC_FALSE;
    if (lpcPrecision == 15)
        return DRFLAC_FALSE;    /* Invalid. */
    lpcPrecision += 1;


    if (!drflac__read_int8(bs, 5, &lpcShift))
        return DRFLAC_FALSE;

    for (i = 0; i < lpcOrder; ++i)
    {
        if (!drflac__read_int32(bs, lpcPrecision, coefficients + i))
            return DRFLAC_FALSE;
    }

    if (!drflac__decode_samples_with_residual(bs, bitsPerSample, blockSize, lpcOrder, lpcShift, coefficients, pDecodedSamples))
        return DRFLAC_FALSE;

    return DRFLAC_TRUE;
}


static drflac_bool32 drflac__read_next_frame_header(drflac_bs* bs, drflac_uint8 streaminfoBitsPerSample, drflac_frame_header* header)
{
    const drflac_uint32 sampleRateTable[12]  = {0, 88200, 176400, 192000, 8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000};
    const drflac_uint8 bitsPerSampleTable[8] = {0, 8, 12, (drflac_uint8)-1, 16, 20, 24, (drflac_uint8)-1};   /* -1 = reserved. */

    drflac_assert(bs != NULL);
    drflac_assert(header != NULL);

    /* Keep looping until we find a valid sync code. */
    for (;;)
    {
       drflac_bool32 isVariableBlockSize = false;
       drflac_uint8 blockSize            = 0;
       drflac_uint8 blockingStrategy     = 0;
       drflac_uint8 crc8                 = 0xCE; /* 0xCE = drflac_crc8(0, 0x3FFE, 14); */
       drflac_uint8 reserved             = 0;
       drflac_uint8 sampleRate           = 0;
       drflac_uint8 channelAssignment    = 0;
       drflac_uint8 bitsPerSample        = 0;

       if (!drflac__find_and_seek_to_next_sync_code(bs))
          return DRFLAC_FALSE;

       if (!drflac__read_uint8(bs, 1, &reserved))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, reserved, 1);

       if (!drflac__read_uint8(bs, 1, &blockingStrategy))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, blockingStrategy, 1);

       if (!drflac__read_uint8(bs, 4, &blockSize))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, blockSize, 4);

       if (!drflac__read_uint8(bs, 4, &sampleRate))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, sampleRate, 4);

       if (!drflac__read_uint8(bs, 4, &channelAssignment))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, channelAssignment, 4);

       if (!drflac__read_uint8(bs, 3, &bitsPerSample))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, bitsPerSample, 3);

       if (!drflac__read_uint8(bs, 1, &reserved))
          return DRFLAC_FALSE;
       crc8 = drflac_crc8(crc8, reserved, 1);

       isVariableBlockSize = blockingStrategy == 1;

       if (isVariableBlockSize)
       {
          drflac_uint64 sampleNumber;
          drflac_result result = drflac__read_utf8_coded_number(bs, &sampleNumber, &crc8);
          if (result != DRFLAC_SUCCESS)
          {
             if (result == DRFLAC_END_OF_STREAM)
                return DRFLAC_FALSE;
             else
                continue;
          }
          header->frameNumber  = 0;
          header->sampleNumber = sampleNumber;
       }
       else
       {
          drflac_uint64 frameNumber = 0;
          drflac_result result = drflac__read_utf8_coded_number(bs, &frameNumber, &crc8);
          if (result != DRFLAC_SUCCESS)
          {
             if (result == DRFLAC_END_OF_STREAM)
                return DRFLAC_FALSE;
             else
                continue;
          }
          header->frameNumber  = (drflac_uint32)frameNumber;   /* <-- Safe cast. */
          header->sampleNumber = 0;
       }


       if (blockSize == 1)
          header->blockSize = 192;
       else if (blockSize >= 2 && blockSize <= 5)
          header->blockSize = 576 * (1 << (blockSize - 2));
       else if (blockSize == 6)
       {
          if (!drflac__read_uint16(bs, 8, &header->blockSize))
             return DRFLAC_FALSE;
          crc8 = drflac_crc8(crc8, header->blockSize, 8);
          header->blockSize += 1;
       }
       else if (blockSize == 7)
       {
          if (!drflac__read_uint16(bs, 16, &header->blockSize))
             return DRFLAC_FALSE;
          crc8 = drflac_crc8(crc8, header->blockSize, 16);
          header->blockSize += 1;
       }
       else
          header->blockSize = 256 * (1 << (blockSize - 8));

       if (sampleRate <= 11)
          header->sampleRate = sampleRateTable[sampleRate];
       else if (sampleRate == 12)
       {
          if (!drflac__read_uint32(bs, 8, &header->sampleRate))
             return DRFLAC_FALSE;
          crc8 = drflac_crc8(crc8, header->sampleRate, 8);
          header->sampleRate *= 1000;
       }
       else if (sampleRate == 13)
       {
          if (!drflac__read_uint32(bs, 16, &header->sampleRate))
             return DRFLAC_FALSE;
          crc8 = drflac_crc8(crc8, header->sampleRate, 16);
       }
       else if (sampleRate == 14)
       {
          if (!drflac__read_uint32(bs, 16, &header->sampleRate))
             return DRFLAC_FALSE;
          crc8 = drflac_crc8(crc8, header->sampleRate, 16);
          header->sampleRate *= 10;
       }
       else
          continue;  /* Invalid. Assume an invalid block. */

       header->channelAssignment = channelAssignment;

       header->bitsPerSample = bitsPerSampleTable[bitsPerSample];
       if (header->bitsPerSample == 0)
          header->bitsPerSample = streaminfoBitsPerSample;

       if (!drflac__read_uint8(bs, 8, &header->crc8))
          return DRFLAC_FALSE;

#ifndef DR_FLAC_NO_CRC
       if (header->crc8 != crc8)
          continue;    /* CRC mismatch. Loop back to the top and find the next sync code. */
#endif
       return DRFLAC_TRUE;
    }
}

static drflac_bool32 drflac__read_subframe_header(drflac_bs* bs, drflac_subframe* pSubframe)
{
   int type;
   drflac_uint8 header;
   if (!drflac__read_uint8(bs, 8, &header))
      return DRFLAC_FALSE;

   /* First bit should always be 0. */
   if ((header & 0x80) != 0)
      return DRFLAC_FALSE;

   type = (header & 0x7E) >> 1;
   if (type == 0)
      pSubframe->subframeType = DRFLAC_SUBFRAME_CONSTANT;
   else if (type == 1)
      pSubframe->subframeType = DRFLAC_SUBFRAME_VERBATIM;
   else
   {
      if ((type & 0x20) != 0) {
         pSubframe->subframeType = DRFLAC_SUBFRAME_LPC;
         pSubframe->lpcOrder = (type & 0x1F) + 1;
      } else if ((type & 0x08) != 0) {
         pSubframe->subframeType = DRFLAC_SUBFRAME_FIXED;
         pSubframe->lpcOrder = (type & 0x07);
         if (pSubframe->lpcOrder > 4) {
            pSubframe->subframeType = DRFLAC_SUBFRAME_RESERVED;
            pSubframe->lpcOrder = 0;
         }
      } else {
         pSubframe->subframeType = DRFLAC_SUBFRAME_RESERVED;
      }
   }

   if (pSubframe->subframeType == DRFLAC_SUBFRAME_RESERVED)
      return DRFLAC_FALSE;

   /* Wasted bits per sample. */
   pSubframe->wastedBitsPerSample = 0;
   if ((header & 0x01) == 1)
   {
      unsigned int wastedBitsPerSample = 0;
      if (!drflac__seek_past_next_set_bit(bs, &wastedBitsPerSample))
         return DRFLAC_FALSE;
      pSubframe->wastedBitsPerSample = (unsigned char)wastedBitsPerSample + 1;
   }

   return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_subframe(drflac_bs* bs, drflac_frame* frame, int subframeIndex, drflac_int32* pDecodedSamplesOut)
{
   drflac_subframe* pSubframe = NULL;
   drflac_assert(bs != NULL);
   drflac_assert(frame != NULL);

   pSubframe = frame->subframes + subframeIndex;
   if (!drflac__read_subframe_header(bs, pSubframe))
      return DRFLAC_FALSE;

   /* Side channels require an extra bit per sample. Took a while to figure that one out... */
   pSubframe->bitsPerSample = frame->header.bitsPerSample;
   if ((frame->header.channelAssignment == DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE || frame->header.channelAssignment == DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE) && subframeIndex == 1) {
      pSubframe->bitsPerSample += 1;
   } else if (frame->header.channelAssignment == DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE && subframeIndex == 0) {
      pSubframe->bitsPerSample += 1;
   }

   /* Need to handle wasted bits per sample. */
   pSubframe->bitsPerSample -= pSubframe->wastedBitsPerSample;
   pSubframe->pDecodedSamples = pDecodedSamplesOut;

   switch (pSubframe->subframeType)
   {
      case DRFLAC_SUBFRAME_CONSTANT:
         {
            drflac__decode_samples__constant(bs, frame->header.blockSize, pSubframe->bitsPerSample, pSubframe->pDecodedSamples);
         } break;

      case DRFLAC_SUBFRAME_VERBATIM:
         {
            drflac__decode_samples__verbatim(bs, frame->header.blockSize, pSubframe->bitsPerSample, pSubframe->pDecodedSamples);
         } break;

      case DRFLAC_SUBFRAME_FIXED:
         {
            drflac__decode_samples__fixed(bs, frame->header.blockSize, pSubframe->bitsPerSample, pSubframe->lpcOrder, pSubframe->pDecodedSamples);
         } break;

      case DRFLAC_SUBFRAME_LPC:
         {
            drflac__decode_samples__lpc(bs, frame->header.blockSize, pSubframe->bitsPerSample, pSubframe->lpcOrder, pSubframe->pDecodedSamples);
         } break;

      default: return DRFLAC_FALSE;
   }

   return DRFLAC_TRUE;
}

static drflac_bool32 drflac__seek_subframe(drflac_bs* bs, drflac_frame* frame, int subframeIndex)
{
   drflac_subframe *pSubframe;

   drflac_assert(bs != NULL);
   drflac_assert(frame != NULL);

   pSubframe = frame->subframes + subframeIndex;
   if (!drflac__read_subframe_header(bs, pSubframe))
      return DRFLAC_FALSE;

   /* Side channels require an extra bit per sample. Took a while to figure that one out... */
   pSubframe->bitsPerSample = frame->header.bitsPerSample;
   if ((frame->header.channelAssignment == DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE || frame->header.channelAssignment == DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE) && subframeIndex == 1) {
      pSubframe->bitsPerSample += 1;
   } else if (frame->header.channelAssignment == DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE && subframeIndex == 0) {
      pSubframe->bitsPerSample += 1;
   }

   /* Need to handle wasted bits per sample. */
   pSubframe->bitsPerSample -= pSubframe->wastedBitsPerSample;
   pSubframe->pDecodedSamples = NULL;

   switch (pSubframe->subframeType)
   {
      case DRFLAC_SUBFRAME_CONSTANT:
         {
            if (!drflac__seek_bits(bs, pSubframe->bitsPerSample))
               return DRFLAC_FALSE;
         } break;

      case DRFLAC_SUBFRAME_VERBATIM:
         {
            unsigned int bitsToSeek = frame->header.blockSize * pSubframe->bitsPerSample;
            if (!drflac__seek_bits(bs, bitsToSeek))
               return DRFLAC_FALSE;
         } break;

      case DRFLAC_SUBFRAME_FIXED:
         {
            unsigned int bitsToSeek = pSubframe->lpcOrder * pSubframe->bitsPerSample;
            if (!drflac__seek_bits(bs, bitsToSeek))
               return DRFLAC_FALSE;

            if (!drflac__read_and_seek_residual(bs, frame->header.blockSize, pSubframe->lpcOrder))
               return DRFLAC_FALSE;
         } break;

      case DRFLAC_SUBFRAME_LPC:
         {
            unsigned char lpcPrecision;
            unsigned int bitsToSeek = pSubframe->lpcOrder * pSubframe->bitsPerSample;
            if (!drflac__seek_bits(bs, bitsToSeek))
               return DRFLAC_FALSE;

            if (!drflac__read_uint8(bs, 4, &lpcPrecision))
               return DRFLAC_FALSE;
            if (lpcPrecision == 15)
               return DRFLAC_FALSE;    /* Invalid. */
            lpcPrecision += 1;


            bitsToSeek = (pSubframe->lpcOrder * lpcPrecision) + 5;    /* +5 for shift. */
            if (!drflac__seek_bits(bs, bitsToSeek))
               return DRFLAC_FALSE;

            if (!drflac__read_and_seek_residual(bs, frame->header.blockSize, pSubframe->lpcOrder))
               return DRFLAC_FALSE;
         } break;

      default: return DRFLAC_FALSE;
   }

   return DRFLAC_TRUE;
}


static DRFLAC_INLINE drflac_uint8 drflac__get_channel_count_from_channel_assignment(drflac_int8 channelAssignment)
{
    drflac_uint8 lookup[] = {1, 2, 3, 4, 5, 6, 7, 8, 2, 2, 2};

    drflac_assert(channelAssignment <= 10);
    return lookup[channelAssignment];
}

static drflac_result drflac__decode_frame(drflac* pFlac)
{
   drflac_uint16 actualCRC16;
   drflac_uint8 paddingSizeInBits;
   drflac_uint16 desiredCRC16;
   int i, channelCount;

   /* This function should be called while the stream is sitting on the first byte after the frame header. */
   drflac_zero_memory(pFlac->currentFrame.subframes, sizeof(pFlac->currentFrame.subframes));

   /* The frame block size must never be larger than the maximum block size defined by the FLAC stream. */
   if (pFlac->currentFrame.header.blockSize > pFlac->maxBlockSize)
      return DRFLAC_ERROR;

   /* The number of channels in the frame must match the channel count from the STREAMINFO block. */
   channelCount = drflac__get_channel_count_from_channel_assignment(pFlac->currentFrame.header.channelAssignment);
   if (channelCount != (int)pFlac->channels)
      return DRFLAC_ERROR;

   for (i = 0; i < channelCount; ++i)
   {
      if (!drflac__decode_subframe(&pFlac->bs, &pFlac->currentFrame, i, pFlac->pDecodedSamples + (pFlac->currentFrame.header.blockSize * i)))
         return DRFLAC_ERROR;
   }

   paddingSizeInBits = DRFLAC_CACHE_L1_BITS_REMAINING(&pFlac->bs) & 7;
   if (paddingSizeInBits > 0)
   {
      drflac_uint8 padding = 0;
      if (!drflac__read_uint8(&pFlac->bs, paddingSizeInBits, &padding))
         return DRFLAC_END_OF_STREAM;
   }

#ifndef DR_FLAC_NO_CRC
   actualCRC16 = drflac__flush_crc16(&pFlac->bs);
#endif
   if (!drflac__read_uint16(&pFlac->bs, 16, &desiredCRC16))
      return DRFLAC_END_OF_STREAM;

#ifndef DR_FLAC_NO_CRC
   if (actualCRC16 != desiredCRC16)
      return DRFLAC_CRC_MISMATCH;    /* CRC mismatch. */
#endif

   pFlac->currentFrame.samplesRemaining = pFlac->currentFrame.header.blockSize * channelCount;

   return DRFLAC_SUCCESS;
}

static drflac_result drflac__seek_frame(drflac* pFlac)
{
#ifndef DR_FLAC_NO_CRC
   drflac_uint16 actualCRC16;
#endif
   drflac_uint16 desiredCRC16;
   int i;
   int channelCount = drflac__get_channel_count_from_channel_assignment(pFlac->currentFrame.header.channelAssignment);

   for (i = 0; i < channelCount; ++i)
   {
      if (!drflac__seek_subframe(&pFlac->bs, &pFlac->currentFrame, i))
         return DRFLAC_ERROR;
   }

   /* Padding. */
   if (!drflac__seek_bits(&pFlac->bs, DRFLAC_CACHE_L1_BITS_REMAINING(&pFlac->bs) & 7))
      return DRFLAC_ERROR;

   /* CRC. */
#ifndef DR_FLAC_NO_CRC
   actualCRC16 = drflac__flush_crc16(&pFlac->bs);
#endif
   if (!drflac__read_uint16(&pFlac->bs, 16, &desiredCRC16))
      return DRFLAC_END_OF_STREAM;

#ifndef DR_FLAC_NO_CRC
   if (actualCRC16 != desiredCRC16)
      return DRFLAC_CRC_MISMATCH;    /* CRC mismatch. */
#endif

   return DRFLAC_SUCCESS;
}

static drflac_bool32 drflac__read_and_decode_next_frame(drflac* pFlac)
{
   drflac_assert(pFlac != NULL);

   for (;;)
   {
      drflac_result result;

      if (!drflac__read_next_frame_header(&pFlac->bs, pFlac->bitsPerSample, &pFlac->currentFrame.header))
         return DRFLAC_FALSE;

      result = drflac__decode_frame(pFlac);
      if (result != DRFLAC_SUCCESS)
      {
         if (result == DRFLAC_CRC_MISMATCH)
            continue;   /* CRC mismatch. Skip to the next frame. */
         return DRFLAC_FALSE;
      }

      return DRFLAC_TRUE;
   }
}


static void drflac__get_current_frame_sample_range(drflac* pFlac, drflac_uint64* pFirstSampleInFrameOut, drflac_uint64* pLastSampleInFrameOut)
{
   unsigned int channelCount;
   drflac_uint64 firstSampleInFrame, lastSampleInFrame;

   drflac_assert(pFlac != NULL);

   channelCount = drflac__get_channel_count_from_channel_assignment(pFlac->currentFrame.header.channelAssignment);

   firstSampleInFrame = pFlac->currentFrame.header.sampleNumber;
   if (firstSampleInFrame == 0)
      firstSampleInFrame = pFlac->currentFrame.header.frameNumber * pFlac->maxBlockSize*channelCount;

   lastSampleInFrame = firstSampleInFrame + (pFlac->currentFrame.header.blockSize*channelCount);
   if (lastSampleInFrame > 0)
      lastSampleInFrame -= 1; /* Needs to be zero based. */

   if (pFirstSampleInFrameOut)
      *pFirstSampleInFrameOut = firstSampleInFrame;
   if (pLastSampleInFrameOut)
      *pLastSampleInFrameOut = lastSampleInFrame;
}

static drflac_bool32 drflac__seek_to_first_frame(drflac* pFlac)
{
   drflac_bool32 result;

   drflac_assert(pFlac != NULL);

   result = drflac__seek_to_byte(&pFlac->bs, pFlac->firstFramePos);

   drflac_zero_memory(&pFlac->currentFrame, sizeof(pFlac->currentFrame));
   return result;
}

static DRFLAC_INLINE drflac_result drflac__seek_to_next_frame(drflac* pFlac)
{
    /* This function should only ever be called while the decoder is sitting on the first byte past the FRAME_HEADER section. */
    drflac_assert(pFlac != NULL);
    return drflac__seek_frame(pFlac);
}

static drflac_bool32 drflac__seek_to_sample__brute_force(drflac* pFlac, drflac_uint64 sampleIndex)
{
    drflac_uint64 runningSampleCount = 0;

    /* We need to find the frame that contains the sample. To do this, we iterate over each frame and inspect it's header. If based on the 
     * header we can determine that the frame contains the sample, we do a full decode of that frame. */
    if (!drflac__seek_to_first_frame(pFlac))
        return DRFLAC_FALSE;

    for (;;)
    {
       drflac_uint64 sampleCountInThisFrame;
       drflac_uint64 firstSampleInFrame = 0;
       drflac_uint64 lastSampleInFrame = 0;

       if (!drflac__read_next_frame_header(&pFlac->bs, pFlac->bitsPerSample, &pFlac->currentFrame.header))
          return DRFLAC_FALSE;

       drflac__get_current_frame_sample_range(pFlac, &firstSampleInFrame, &lastSampleInFrame);

       sampleCountInThisFrame = (lastSampleInFrame - firstSampleInFrame) + 1;
       if (sampleIndex < (runningSampleCount + sampleCountInThisFrame))
       {
          /* The sample should be in this frame. We need to fully decode it, however if it's an invalid frame (a CRC mismatch), we need to pretend 
           * it never existed and keep iterating. */
          drflac_result result = drflac__decode_frame(pFlac);
          if (result == DRFLAC_SUCCESS)
          {
             /* The frame is valid. We just need to skip over some samples to ensure it's sample-exact. */
             drflac_uint64 samplesToDecode = (size_t)(sampleIndex - runningSampleCount);    /* <-- Safe cast because the maximum number of samples in a frame is 65535. */
             if (samplesToDecode == 0)
                return DRFLAC_TRUE;
             return drflac_read_s32(pFlac, samplesToDecode, NULL) != 0;  /* <-- If this fails, something bad has happened (it should never fail). */
          }
          else
          {
             if (result == DRFLAC_CRC_MISMATCH)
                continue;   /* CRC mismatch. Pretend this frame never existed. */
             return DRFLAC_FALSE;
          }
       }
       else
       {
          /* It's not in this frame. We need to seek past the frame, but check if there was a CRC mismatch. If so, we pretend this
           * frame never existed and leave the running sample count untouched. */
          drflac_result result = drflac__seek_to_next_frame(pFlac);
          if (result == DRFLAC_SUCCESS)
             runningSampleCount += sampleCountInThisFrame;
          else
          {
             if (result == DRFLAC_CRC_MISMATCH)
                continue;   /* CRC mismatch. Pretend this frame never existed. */
             return DRFLAC_FALSE;
          }
       }
    }
}


static drflac_bool32 drflac__seek_to_sample__seek_table(drflac* pFlac, drflac_uint64 sampleIndex)
{
    drflac_seekpoint closestSeekpoint = {0, 0, 0};
    drflac_uint32 seekpointCount;
    drflac_uint32 seekpointsRemaining;
    drflac_uint64 runningSampleCount;

    drflac_assert(pFlac != NULL);

    if (pFlac->seektablePos == 0)
        return DRFLAC_FALSE;

    if (!drflac__seek_to_byte(&pFlac->bs, pFlac->seektablePos))
        return DRFLAC_FALSE;

    /* The number of seek points is derived from the size of the SEEKTABLE block. */
    seekpointCount = pFlac->seektableSize / 18;   /* 18 = the size of each seek point. */
    if (seekpointCount == 0)
        return DRFLAC_FALSE;   /* Would this ever happen? */

    seekpointsRemaining = seekpointCount;
    while (seekpointsRemaining > 0)
    {
       drflac_seekpoint seekpoint;
       if (!drflac__read_uint64(&pFlac->bs, 64, &seekpoint.firstSample))
          break;
       if (!drflac__read_uint64(&pFlac->bs, 64, &seekpoint.frameOffset))
          break;
       if (!drflac__read_uint16(&pFlac->bs, 16, &seekpoint.sampleCount))
          break;

       /* Note that the seekpoint sample is based on a single channel. The input sample (sampleIndex) is based on interleaving, thus
        * we need to multiple the seekpoint's sample by the channel count. */
       if (seekpoint.firstSample*pFlac->channels > sampleIndex)
          break;

       closestSeekpoint = seekpoint;
       seekpointsRemaining -= 1;
    }

    /* At this point we should have found the seekpoint closest to our sample. We need to seek to it using basically the same
     * technique as we use with the brute force method. */
    if (!drflac__seek_to_byte(&pFlac->bs, pFlac->firstFramePos + closestSeekpoint.frameOffset))
        return DRFLAC_FALSE;

    runningSampleCount = closestSeekpoint.firstSample*pFlac->channels;
    for (;;)
    {
       drflac_uint64 sampleCountInThisFrame;
       drflac_uint64 firstSampleInFrame = 0;
       drflac_uint64 lastSampleInFrame = 0;

       if (!drflac__read_next_frame_header(&pFlac->bs, pFlac->bitsPerSample, &pFlac->currentFrame.header))
          return DRFLAC_FALSE;

       drflac__get_current_frame_sample_range(pFlac, &firstSampleInFrame, &lastSampleInFrame);

       sampleCountInThisFrame = (lastSampleInFrame - firstSampleInFrame) + 1;
       if (sampleIndex < (runningSampleCount + sampleCountInThisFrame))
       {
          /* The sample should be in this frame. We need to fully decode it, however if it's an invalid frame (a CRC mismatch), we need to pretend
           * it never existed and keep iterating. */
          drflac_result result = drflac__decode_frame(pFlac);

          if (result == DRFLAC_SUCCESS)
          {
             /* The frame is valid. We just need to skip over some samples to ensure it's sample-exact. */
             drflac_uint64 samplesToDecode = (size_t)(sampleIndex - runningSampleCount);    /* <-- Safe cast because the maximum number of samples in a frame is 65535. */
             if (samplesToDecode == 0)
                return DRFLAC_TRUE;
             return drflac_read_s32(pFlac, samplesToDecode, NULL) != 0;  /* <-- If this fails, something bad has happened (it should never fail). */
          }
          else
          {
             if (result == DRFLAC_CRC_MISMATCH)
                continue;   /* CRC mismatch. Pretend this frame never existed. */
             return DRFLAC_FALSE;
          }
       }
       else
       {
          /* It's not in this frame. We need to seek past the frame, but check if there was a CRC mismatch. If so, we pretend this
           * frame never existed and leave the running sample count untouched. */
          drflac_result result = drflac__seek_to_next_frame(pFlac);
          if (result == DRFLAC_SUCCESS)
             runningSampleCount += sampleCountInThisFrame;
          else
          {
             if (result == DRFLAC_CRC_MISMATCH)
                continue;   /* CRC mismatch. Pretend this frame never existed. */
             return DRFLAC_FALSE;
          }
       }
    }
}


#ifndef DR_FLAC_NO_OGG
typedef struct
{
    drflac_uint8 capturePattern[4];  /* Should be "OggS" */
    drflac_uint8 structureVersion;   /* Always 0. */
    drflac_uint8 headerType;
    drflac_uint64 granulePosition;
    drflac_uint32 serialNumber;
    drflac_uint32 sequenceNumber;
    drflac_uint32 checksum;
    drflac_uint8 segmentCount;
    drflac_uint8 segmentTable[255];
} drflac_ogg_page_header;
#endif

typedef struct
{
    drflac_read_proc onRead;
    drflac_seek_proc onSeek;
    drflac_meta_proc onMeta;
    drflac_container container;
    void* pUserData;
    void* pUserDataMD;
    drflac_uint32 sampleRate;
    drflac_uint8  channels;
    drflac_uint8  bitsPerSample;
    drflac_uint64 totalSampleCount;
    drflac_uint16 maxBlockSize;
    drflac_uint64 runningFilePos;
    drflac_bool32 hasStreamInfoBlock;
    drflac_bool32 hasMetadataBlocks;
    drflac_bs bs;                           /* <-- A bit streamer is required for loading data during initialization. */
    drflac_frame_header firstFrameHeader;   /* <-- The header of the first frame that was read during relaxed initalization. Only set if there is no STREAMINFO block. */

#ifndef DR_FLAC_NO_OGG
    drflac_uint32 oggSerial;
    drflac_uint64 oggFirstBytePos;
    drflac_ogg_page_header oggBosHeader;
#endif
} drflac_init_info;

static DRFLAC_INLINE void drflac__decode_block_header(drflac_uint32 blockHeader, drflac_uint8* isLastBlock, drflac_uint8* blockType, drflac_uint32* blockSize)
{
    blockHeader = drflac__be2host_32(blockHeader);
    *isLastBlock = (blockHeader & (0x01 << 31)) >> 31;
    *blockType   = (blockHeader & (0x7F << 24)) >> 24;
    *blockSize   = (blockHeader & 0xFFFFFF);
}

static DRFLAC_INLINE drflac_bool32 drflac__read_and_decode_block_header(drflac_read_proc onRead, void* pUserData, drflac_uint8* isLastBlock, drflac_uint8* blockType, drflac_uint32* blockSize)
{
    drflac_uint32 blockHeader;
    if (onRead(pUserData, &blockHeader, 4) != 4) {
        return DRFLAC_FALSE;
    }

    drflac__decode_block_header(blockHeader, isLastBlock, blockType, blockSize);
    return DRFLAC_TRUE;
}

drflac_bool32 drflac__read_streaminfo(drflac_read_proc onRead, void* pUserData, drflac_streaminfo* pStreamInfo)
{
    drflac_uint32 blockSizes;
    drflac_uint64 frameSizes = 0;
    drflac_uint64 importantProps;
    drflac_uint8 md5[16];

    /* min/max block size. */
    if (onRead(pUserData, &blockSizes, 4) != 4)
        return DRFLAC_FALSE;

    /* min/max frame size. */
    if (onRead(pUserData, &frameSizes, 6) != 6)
        return DRFLAC_FALSE;

    /* Sample rate, channels, bits per sample and total sample count. */
    if (onRead(pUserData, &importantProps, 8) != 8)
        return DRFLAC_FALSE;

    /* MD5 */
    if (onRead(pUserData, md5, sizeof(md5)) != sizeof(md5))
        return DRFLAC_FALSE;

    blockSizes     = drflac__be2host_32(blockSizes);
    frameSizes     = drflac__be2host_64(frameSizes);
    importantProps = drflac__be2host_64(importantProps);

    pStreamInfo->minBlockSize     = (blockSizes & 0xFFFF0000) >> 16;
    pStreamInfo->maxBlockSize     = blockSizes & 0x0000FFFF;
    pStreamInfo->minFrameSize     = (drflac_uint32)((frameSizes     & (drflac_uint64)0xFFFFFF0000000000) >> 40);
    pStreamInfo->maxFrameSize     = (drflac_uint32)((frameSizes     & (drflac_uint64)0x000000FFFFFF0000) >> 16);
    pStreamInfo->sampleRate       = (drflac_uint32)((importantProps & (drflac_uint64)0xFFFFF00000000000) >> 44);
    pStreamInfo->channels         = (drflac_uint8 )((importantProps & (drflac_uint64)0x00000E0000000000) >> 41) + 1;
    pStreamInfo->bitsPerSample    = (drflac_uint8 )((importantProps & (drflac_uint64)0x000001F000000000) >> 36) + 1;
    pStreamInfo->totalSampleCount = (importantProps & (drflac_uint64)0x0000000FFFFFFFFF) * pStreamInfo->channels;
    drflac_copy_memory(pStreamInfo->md5, md5, sizeof(md5));

    return DRFLAC_TRUE;
}

drflac_bool32 drflac__read_and_decode_metadata(drflac* pFlac)
{
    /* We want to keep track of the byte position in the stream of the seektable. At the time of calling this function we know that
     * we'll be sitting on byte 42. */
    drflac_uint64 runningFilePos = 42;
    drflac_uint64 seektablePos   = 0;
    drflac_uint32 seektableSize  = 0;

    drflac_assert(pFlac != NULL);

    for (;;)
    {
       drflac_metadata metadata;
       drflac_uint8 isLastBlock = 0;
       drflac_uint8 blockType   = 0;
       drflac_uint32 blockSize  = 0;

       if (!drflac__read_and_decode_block_header(pFlac->bs.onRead, pFlac->bs.pUserData, &isLastBlock, &blockType, &blockSize))
          return DRFLAC_FALSE;
       runningFilePos += 4;


       metadata.type = blockType;
       metadata.pRawData = NULL;
       metadata.rawDataSize = 0;

       switch (blockType)
       {
          case DRFLAC_METADATA_BLOCK_TYPE_APPLICATION:
             {
                if (pFlac->onMeta) {
                   void* pRawData = DRFLAC_MALLOC(blockSize);
                   if (pRawData == NULL)
                      return DRFLAC_FALSE;

                   if (pFlac->bs.onRead(pFlac->bs.pUserData, pRawData, blockSize) != blockSize) {
                      DRFLAC_FREE(pRawData);
                      return DRFLAC_FALSE;
                   }

                   metadata.pRawData = pRawData;
                   metadata.rawDataSize = blockSize;
                   metadata.data.application.id       = drflac__be2host_32(*(drflac_uint32*)pRawData);
                   metadata.data.application.pData    = (const void*)((drflac_uint8*)pRawData + sizeof(drflac_uint32));
                   metadata.data.application.dataSize = blockSize - sizeof(drflac_uint32);
                   pFlac->onMeta(pFlac->pUserDataMD, &metadata);

                   DRFLAC_FREE(pRawData);
                }
             } break;

          case DRFLAC_METADATA_BLOCK_TYPE_SEEKTABLE:
             {
                seektablePos  = runningFilePos;
                seektableSize = blockSize;

                if (pFlac->onMeta)
                {
                   drflac_uint32 iSeekpoint;
                   void* pRawData = DRFLAC_MALLOC(blockSize);
                   if (pRawData == NULL)
                      return DRFLAC_FALSE;

                   if (pFlac->bs.onRead(pFlac->bs.pUserData, pRawData, blockSize) != blockSize) {
                      DRFLAC_FREE(pRawData);
                      return DRFLAC_FALSE;
                   }

                   metadata.pRawData = pRawData;
                   metadata.rawDataSize = blockSize;
                   metadata.data.seektable.seekpointCount = blockSize/sizeof(drflac_seekpoint);
                   metadata.data.seektable.pSeekpoints = (const drflac_seekpoint*)pRawData;

                   /* Endian swap. */
                   for (iSeekpoint = 0; iSeekpoint < metadata.data.seektable.seekpointCount; ++iSeekpoint) {
                      drflac_seekpoint* pSeekpoint = (drflac_seekpoint*)pRawData + iSeekpoint;
                      pSeekpoint->firstSample = drflac__be2host_64(pSeekpoint->firstSample);
                      pSeekpoint->frameOffset = drflac__be2host_64(pSeekpoint->frameOffset);
                      pSeekpoint->sampleCount = drflac__be2host_16(pSeekpoint->sampleCount);
                   }

                   pFlac->onMeta(pFlac->pUserDataMD, &metadata);

                   DRFLAC_FREE(pRawData);
                }
             } break;

          case DRFLAC_METADATA_BLOCK_TYPE_VORBIS_COMMENT:
             {
                if (pFlac->onMeta)
                {
                   const char* pRunningData;
                   void* pRawData = DRFLAC_MALLOC(blockSize);
                   if (pRawData == NULL)
                      return DRFLAC_FALSE;

                   if (pFlac->bs.onRead(pFlac->bs.pUserData, pRawData, blockSize) != blockSize) {
                      DRFLAC_FREE(pRawData);
                      return DRFLAC_FALSE;
                   }

                   metadata.pRawData = pRawData;
                   metadata.rawDataSize = blockSize;

                   pRunningData = (const char*)pRawData;
                   metadata.data.vorbis_comment.vendorLength = drflac__le2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.vorbis_comment.vendor       = pRunningData;                                      pRunningData += metadata.data.vorbis_comment.vendorLength;
                   metadata.data.vorbis_comment.commentCount = drflac__le2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.vorbis_comment.comments     = pRunningData;
                   pFlac->onMeta(pFlac->pUserDataMD, &metadata);

                   DRFLAC_FREE(pRawData);
                }
             } break;

          case DRFLAC_METADATA_BLOCK_TYPE_CUESHEET:
             {
                if (pFlac->onMeta)
                {
                   const char* pRunningData;
                   void* pRawData = DRFLAC_MALLOC(blockSize);
                   if (pRawData == NULL)
                      return DRFLAC_FALSE;

                   if (pFlac->bs.onRead(pFlac->bs.pUserData, pRawData, blockSize) != blockSize) {
                      DRFLAC_FREE(pRawData);
                      return DRFLAC_FALSE;
                   }

                   metadata.pRawData = pRawData;
                   metadata.rawDataSize = blockSize;

                   pRunningData = (const char*)pRawData;
                   drflac_copy_memory(metadata.data.cuesheet.catalog, pRunningData, 128);                        pRunningData += 128;
                   metadata.data.cuesheet.leadInSampleCount = drflac__be2host_64(*(drflac_uint64*)pRunningData); pRunningData += 4;
                   metadata.data.cuesheet.isCD              = ((pRunningData[0] & 0x80) >> 7) != 0;              pRunningData += 259;
                   metadata.data.cuesheet.trackCount        = pRunningData[0];                                   pRunningData += 1;
                   metadata.data.cuesheet.pTrackData        = (const drflac_uint8*)pRunningData;
                   pFlac->onMeta(pFlac->pUserDataMD, &metadata);

                   DRFLAC_FREE(pRawData);
                }
             } break;

          case DRFLAC_METADATA_BLOCK_TYPE_PICTURE:
             {
                if (pFlac->onMeta)
                {
                   const char* pRunningData;
                   void* pRawData = DRFLAC_MALLOC(blockSize);
                   if (pRawData == NULL)
                      return DRFLAC_FALSE;

                   if (pFlac->bs.onRead(pFlac->bs.pUserData, pRawData, blockSize) != blockSize) {
                      DRFLAC_FREE(pRawData);
                      return DRFLAC_FALSE;
                   }

                   metadata.pRawData = pRawData;
                   metadata.rawDataSize = blockSize;

                   pRunningData = (const char*)pRawData;
                   metadata.data.picture.type              = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.mimeLength        = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.mime              = pRunningData;                                      pRunningData += metadata.data.picture.mimeLength;
                   metadata.data.picture.descriptionLength = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.description       = pRunningData;
                   metadata.data.picture.width             = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.height            = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.colorDepth        = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.indexColorCount   = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.pictureDataSize   = drflac__be2host_32(*(drflac_uint32*)pRunningData); pRunningData += 4;
                   metadata.data.picture.pPictureData      = (const drflac_uint8*)pRunningData;
                   pFlac->onMeta(pFlac->pUserDataMD, &metadata);

                   DRFLAC_FREE(pRawData);
                }
             } break;

          case DRFLAC_METADATA_BLOCK_TYPE_PADDING:
             {
                if (pFlac->onMeta)
                {
                   metadata.data.padding.unused = 0;

                   /* Padding doesn't have anything meaningful in it, so just skip over it, but make sure the caller is aware of it by firing the callback. */
                   if (!pFlac->bs.onSeek(pFlac->bs.pUserData, blockSize, drflac_seek_origin_current))
                      isLastBlock = DRFLAC_TRUE;  /* An error occured while seeking. Attempt to recover by treating this as the last block which will in turn terminate the loop. */
                   else
                      pFlac->onMeta(pFlac->pUserDataMD, &metadata);
                }
             }
             break;

          case DRFLAC_METADATA_BLOCK_TYPE_INVALID:
             {
                /* Invalid chunk. Just skip over this one. */
                if (pFlac->onMeta)
                {
                   if (!pFlac->bs.onSeek(pFlac->bs.pUserData, blockSize, drflac_seek_origin_current))
                      isLastBlock = DRFLAC_TRUE;  /* An error occured while seeking. Attempt to recover by treating this as the last block which will in turn terminate the loop. */
                }
             }

          default:
             {
                /* It's an unknown chunk, but not necessarily invalid. There's a chance more metadata blocks might be defined later on, so we
                 * can at the very least report the chunk to the application and let it look at the raw data. */
                if (pFlac->onMeta)
                {
                   void* pRawData = DRFLAC_MALLOC(blockSize);
                   if (pRawData == NULL)
                      return DRFLAC_FALSE;

                   if (pFlac->bs.onRead(pFlac->bs.pUserData, pRawData, blockSize) != blockSize) {
                      DRFLAC_FREE(pRawData);
                      return DRFLAC_FALSE;
                   }

                   metadata.pRawData = pRawData;
                   metadata.rawDataSize = blockSize;
                   pFlac->onMeta(pFlac->pUserDataMD, &metadata);

                   DRFLAC_FREE(pRawData);
                }
             } break;
       }

       /* If we're not handling metadata, just skip over the block. If we are, it will have been handled earlier in the switch statement above. */
       if (pFlac->onMeta == NULL && blockSize > 0)
       {
          if (!pFlac->bs.onSeek(pFlac->bs.pUserData, blockSize, drflac_seek_origin_current))
             isLastBlock = DRFLAC_TRUE;
       }

       runningFilePos += blockSize;
       if (isLastBlock)
          break;
    }

    pFlac->seektablePos = seektablePos;
    pFlac->seektableSize = seektableSize;
    pFlac->firstFramePos = runningFilePos;

    return DRFLAC_TRUE;
}

drflac_bool32 drflac__init_private__native(drflac_init_info* pInit, drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, void* pUserData, void* pUserDataMD, drflac_bool32 relaxed)
{
    drflac_uint8 isLastBlock = 0;
    drflac_uint8 blockType   = 0;
    drflac_uint32 blockSize  = 0;

    (void)onSeek;

    /* Pre: The bit stream should be sitting just past the 4-byte id header. */

    pInit->container = drflac_container_native;

    /* The first metadata block should be the STREAMINFO block. */
    if (!drflac__read_and_decode_block_header(onRead, pUserData, &isLastBlock, &blockType, &blockSize))
        return DRFLAC_FALSE;

    if (blockType != DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO || blockSize != 34)
    {
       /* We're opening in strict mode and the first block is not the STREAMINFO block. Error. */
       if (!relaxed)
          return DRFLAC_FALSE;

       /* Relaxed mode. To open from here we need to just find the first frame and set the sample rate, etc. to whatever is defined
        * for that frame. */
       pInit->hasStreamInfoBlock = DRFLAC_FALSE;
       pInit->hasMetadataBlocks  = DRFLAC_FALSE;

       if (!drflac__read_next_frame_header(&pInit->bs, 0, &pInit->firstFrameHeader))
          return DRFLAC_FALSE;    /* Couldn't find a frame. */

       if (pInit->firstFrameHeader.bitsPerSample == 0)
          return DRFLAC_FALSE;    /* Failed to initialize because the first frame depends on the STREAMINFO block, which does not exist. */

       pInit->sampleRate    = pInit->firstFrameHeader.sampleRate;
       pInit->channels      = drflac__get_channel_count_from_channel_assignment(pInit->firstFrameHeader.channelAssignment);
       pInit->bitsPerSample = pInit->firstFrameHeader.bitsPerSample;
       pInit->maxBlockSize  = 65535;   /* <-- See notes here: https://xiph.org/flac/format.html#metadata_block_streaminfo */
       return DRFLAC_TRUE;
    }
    else
    {
        drflac_streaminfo streaminfo;
        if (!drflac__read_streaminfo(onRead, pUserData, &streaminfo))
            return DRFLAC_FALSE;

        pInit->hasStreamInfoBlock = DRFLAC_TRUE;
        pInit->sampleRate         = streaminfo.sampleRate;
        pInit->channels           = streaminfo.channels;
        pInit->bitsPerSample      = streaminfo.bitsPerSample;
        pInit->totalSampleCount   = streaminfo.totalSampleCount;
        pInit->maxBlockSize       = streaminfo.maxBlockSize;    /* Don't care about the min block size - only the max (used for determining the size of the memory allocation). */
        pInit->hasMetadataBlocks = !isLastBlock;

        if (onMeta) {
            drflac_metadata metadata;
            metadata.type = DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO;
            metadata.pRawData = NULL;
            metadata.rawDataSize = 0;
            metadata.data.streaminfo = streaminfo;
            onMeta(pUserDataMD, &metadata);
        }

        return DRFLAC_TRUE;
    }
}

#ifndef DR_FLAC_NO_OGG
#define DRFLAC_OGG_MAX_PAGE_SIZE            65307
#define DRFLAC_OGG_CAPTURE_PATTERN_CRC32    1605413199  /* CRC-32 of "OggS". */

typedef enum
{
    drflac_ogg_recover_on_crc_mismatch,
    drflac_ogg_fail_on_crc_mismatch
} drflac_ogg_crc_mismatch_recovery;


static drflac_uint32 drflac__crc32_table[] = {
    0x00000000L, 0x04C11DB7L, 0x09823B6EL, 0x0D4326D9L,
    0x130476DCL, 0x17C56B6BL, 0x1A864DB2L, 0x1E475005L,
    0x2608EDB8L, 0x22C9F00FL, 0x2F8AD6D6L, 0x2B4BCB61L,
    0x350C9B64L, 0x31CD86D3L, 0x3C8EA00AL, 0x384FBDBDL,
    0x4C11DB70L, 0x48D0C6C7L, 0x4593E01EL, 0x4152FDA9L,
    0x5F15ADACL, 0x5BD4B01BL, 0x569796C2L, 0x52568B75L,
    0x6A1936C8L, 0x6ED82B7FL, 0x639B0DA6L, 0x675A1011L,
    0x791D4014L, 0x7DDC5DA3L, 0x709F7B7AL, 0x745E66CDL,
    0x9823B6E0L, 0x9CE2AB57L, 0x91A18D8EL, 0x95609039L,
    0x8B27C03CL, 0x8FE6DD8BL, 0x82A5FB52L, 0x8664E6E5L,
    0xBE2B5B58L, 0xBAEA46EFL, 0xB7A96036L, 0xB3687D81L,
    0xAD2F2D84L, 0xA9EE3033L, 0xA4AD16EAL, 0xA06C0B5DL,
    0xD4326D90L, 0xD0F37027L, 0xDDB056FEL, 0xD9714B49L,
    0xC7361B4CL, 0xC3F706FBL, 0xCEB42022L, 0xCA753D95L,
    0xF23A8028L, 0xF6FB9D9FL, 0xFBB8BB46L, 0xFF79A6F1L,
    0xE13EF6F4L, 0xE5FFEB43L, 0xE8BCCD9AL, 0xEC7DD02DL,
    0x34867077L, 0x30476DC0L, 0x3D044B19L, 0x39C556AEL,
    0x278206ABL, 0x23431B1CL, 0x2E003DC5L, 0x2AC12072L,
    0x128E9DCFL, 0x164F8078L, 0x1B0CA6A1L, 0x1FCDBB16L,
    0x018AEB13L, 0x054BF6A4L, 0x0808D07DL, 0x0CC9CDCAL,
    0x7897AB07L, 0x7C56B6B0L, 0x71159069L, 0x75D48DDEL,
    0x6B93DDDBL, 0x6F52C06CL, 0x6211E6B5L, 0x66D0FB02L,
    0x5E9F46BFL, 0x5A5E5B08L, 0x571D7DD1L, 0x53DC6066L,
    0x4D9B3063L, 0x495A2DD4L, 0x44190B0DL, 0x40D816BAL,
    0xACA5C697L, 0xA864DB20L, 0xA527FDF9L, 0xA1E6E04EL,
    0xBFA1B04BL, 0xBB60ADFCL, 0xB6238B25L, 0xB2E29692L,
    0x8AAD2B2FL, 0x8E6C3698L, 0x832F1041L, 0x87EE0DF6L,
    0x99A95DF3L, 0x9D684044L, 0x902B669DL, 0x94EA7B2AL,
    0xE0B41DE7L, 0xE4750050L, 0xE9362689L, 0xEDF73B3EL,
    0xF3B06B3BL, 0xF771768CL, 0xFA325055L, 0xFEF34DE2L,
    0xC6BCF05FL, 0xC27DEDE8L, 0xCF3ECB31L, 0xCBFFD686L,
    0xD5B88683L, 0xD1799B34L, 0xDC3ABDEDL, 0xD8FBA05AL,
    0x690CE0EEL, 0x6DCDFD59L, 0x608EDB80L, 0x644FC637L,
    0x7A089632L, 0x7EC98B85L, 0x738AAD5CL, 0x774BB0EBL,
    0x4F040D56L, 0x4BC510E1L, 0x46863638L, 0x42472B8FL,
    0x5C007B8AL, 0x58C1663DL, 0x558240E4L, 0x51435D53L,
    0x251D3B9EL, 0x21DC2629L, 0x2C9F00F0L, 0x285E1D47L,
    0x36194D42L, 0x32D850F5L, 0x3F9B762CL, 0x3B5A6B9BL,
    0x0315D626L, 0x07D4CB91L, 0x0A97ED48L, 0x0E56F0FFL,
    0x1011A0FAL, 0x14D0BD4DL, 0x19939B94L, 0x1D528623L,
    0xF12F560EL, 0xF5EE4BB9L, 0xF8AD6D60L, 0xFC6C70D7L,
    0xE22B20D2L, 0xE6EA3D65L, 0xEBA91BBCL, 0xEF68060BL,
    0xD727BBB6L, 0xD3E6A601L, 0xDEA580D8L, 0xDA649D6FL,
    0xC423CD6AL, 0xC0E2D0DDL, 0xCDA1F604L, 0xC960EBB3L,
    0xBD3E8D7EL, 0xB9FF90C9L, 0xB4BCB610L, 0xB07DABA7L,
    0xAE3AFBA2L, 0xAAFBE615L, 0xA7B8C0CCL, 0xA379DD7BL,
    0x9B3660C6L, 0x9FF77D71L, 0x92B45BA8L, 0x9675461FL,
    0x8832161AL, 0x8CF30BADL, 0x81B02D74L, 0x857130C3L,
    0x5D8A9099L, 0x594B8D2EL, 0x5408ABF7L, 0x50C9B640L,
    0x4E8EE645L, 0x4A4FFBF2L, 0x470CDD2BL, 0x43CDC09CL,
    0x7B827D21L, 0x7F436096L, 0x7200464FL, 0x76C15BF8L,
    0x68860BFDL, 0x6C47164AL, 0x61043093L, 0x65C52D24L,
    0x119B4BE9L, 0x155A565EL, 0x18197087L, 0x1CD86D30L,
    0x029F3D35L, 0x065E2082L, 0x0B1D065BL, 0x0FDC1BECL,
    0x3793A651L, 0x3352BBE6L, 0x3E119D3FL, 0x3AD08088L,
    0x2497D08DL, 0x2056CD3AL, 0x2D15EBE3L, 0x29D4F654L,
    0xC5A92679L, 0xC1683BCEL, 0xCC2B1D17L, 0xC8EA00A0L,
    0xD6AD50A5L, 0xD26C4D12L, 0xDF2F6BCBL, 0xDBEE767CL,
    0xE3A1CBC1L, 0xE760D676L, 0xEA23F0AFL, 0xEEE2ED18L,
    0xF0A5BD1DL, 0xF464A0AAL, 0xF9278673L, 0xFDE69BC4L,
    0x89B8FD09L, 0x8D79E0BEL, 0x803AC667L, 0x84FBDBD0L,
    0x9ABC8BD5L, 0x9E7D9662L, 0x933EB0BBL, 0x97FFAD0CL,
    0xAFB010B1L, 0xAB710D06L, 0xA6322BDFL, 0xA2F33668L,
    0xBCB4666DL, 0xB8757BDAL, 0xB5365D03L, 0xB1F740B4L
};

static DRFLAC_INLINE drflac_uint32 drflac_crc32_byte(drflac_uint32 crc32, drflac_uint8 data)
{
#ifndef DR_FLAC_NO_CRC
    return (crc32 << 8) ^ drflac__crc32_table[(drflac_uint8)((crc32 >> 24) & 0xFF) ^ data];
#else
    (void)data;
    return crc32;
#endif
}

#if 0
static DRFLAC_INLINE drflac_uint32 drflac_crc32_uint32(drflac_uint32 crc32, drflac_uint32 data)
{
    crc32 = drflac_crc32_byte(crc32, (drflac_uint8)((data >> 24) & 0xFF));
    crc32 = drflac_crc32_byte(crc32, (drflac_uint8)((data >> 16) & 0xFF));
    crc32 = drflac_crc32_byte(crc32, (drflac_uint8)((data >>  8) & 0xFF));
    crc32 = drflac_crc32_byte(crc32, (drflac_uint8)((data >>  0) & 0xFF));
    return crc32;
}

static DRFLAC_INLINE drflac_uint32 drflac_crc32_uint64(drflac_uint32 crc32, drflac_uint64 data)
{
    crc32 = drflac_crc32_uint32(crc32, (drflac_uint32)((data >> 32) & 0xFFFFFFFF));
    crc32 = drflac_crc32_uint32(crc32, (drflac_uint32)((data >>  0) & 0xFFFFFFFF));
    return crc32;
}
#endif

static DRFLAC_INLINE drflac_uint32 drflac_crc32_buffer(drflac_uint32 crc32, drflac_uint8* pData, drflac_uint32 dataSize)
{
   drflac_uint32 i;

   /* This can be optimized. */
   for (i = 0; i < dataSize; ++i)
      crc32 = drflac_crc32_byte(crc32, pData[i]);
   return crc32;
}


static DRFLAC_INLINE drflac_bool32 drflac_ogg__is_capture_pattern(drflac_uint8 pattern[4])
{
    return pattern[0] == 'O' && pattern[1] == 'g' && pattern[2] == 'g' && pattern[3] == 'S';
}

static DRFLAC_INLINE drflac_uint32 drflac_ogg__get_page_header_size(drflac_ogg_page_header* pHeader)
{
    return 27 + pHeader->segmentCount;
}

static DRFLAC_INLINE drflac_uint32 drflac_ogg__get_page_body_size(drflac_ogg_page_header* pHeader)
{
   int i;
   drflac_uint32 pageBodySize = 0;

   for (i = 0; i < pHeader->segmentCount; ++i)
      pageBodySize += pHeader->segmentTable[i];

   return pageBodySize;
}

drflac_result drflac_ogg__read_page_header_after_capture_pattern(drflac_read_proc onRead, void* pUserData, drflac_ogg_page_header* pHeader, drflac_uint32* pBytesRead, drflac_uint32* pCRC32)
{
    drflac_uint32 i;
    drflac_uint8 data[23];

    drflac_assert(*pCRC32 == DRFLAC_OGG_CAPTURE_PATTERN_CRC32);

    if (onRead(pUserData, data, 23) != 23)
        return DRFLAC_END_OF_STREAM;
    *pBytesRead += 23;

    pHeader->structureVersion = data[0];
    pHeader->headerType       = data[1];
    drflac_copy_memory(&pHeader->granulePosition, &data[ 2], 8);
    drflac_copy_memory(&pHeader->serialNumber,    &data[10], 4);
    drflac_copy_memory(&pHeader->sequenceNumber,  &data[14], 4);
    drflac_copy_memory(&pHeader->checksum,        &data[18], 4);
    pHeader->segmentCount     = data[22];

    /* Calculate the CRC. Note that for the calculation the checksum part of the page needs to be set to 0. */
    data[18] = 0;
    data[19] = 0;
    data[20] = 0;
    data[21] = 0;

    for (i = 0; i < 23; ++i)
        *pCRC32 = drflac_crc32_byte(*pCRC32, data[i]);

    if (onRead(pUserData, pHeader->segmentTable, pHeader->segmentCount) != pHeader->segmentCount)
        return DRFLAC_END_OF_STREAM;

    *pBytesRead += pHeader->segmentCount;

    for (i = 0; i < pHeader->segmentCount; ++i)
        *pCRC32 = drflac_crc32_byte(*pCRC32, pHeader->segmentTable[i]);

    return DRFLAC_SUCCESS;
}

drflac_result drflac_ogg__read_page_header(drflac_read_proc onRead, void* pUserData, drflac_ogg_page_header* pHeader, drflac_uint32* pBytesRead, drflac_uint32* pCRC32)
{
    drflac_uint8 id[4];

    *pBytesRead = 0;

    if (onRead(pUserData, id, 4) != 4)
        return DRFLAC_END_OF_STREAM;
    *pBytesRead += 4;

    /* We need to read byte-by-byte until we find the OggS capture pattern. */
    for (;;)
    {
        if (drflac_ogg__is_capture_pattern(id))
        {
           drflac_result result;
           *pCRC32 = DRFLAC_OGG_CAPTURE_PATTERN_CRC32;

           result = drflac_ogg__read_page_header_after_capture_pattern(onRead, pUserData, pHeader, pBytesRead, pCRC32);
           if (result == DRFLAC_SUCCESS)
              return DRFLAC_SUCCESS;

           if (result == DRFLAC_CRC_MISMATCH)
              continue;
           return result;
        }
        else
        {
           /* The first 4 bytes did not equal the capture pattern. Read the next byte and try again. */
           id[0] = id[1];
           id[1] = id[2];
           id[2] = id[3];
           if (onRead(pUserData, &id[3], 1) != 1)
              return DRFLAC_END_OF_STREAM;
           *pBytesRead += 1;
        }
    }
}


/* The main part of the Ogg encapsulation is the conversion from the physical Ogg bitstream to the native FLAC bitstream. It works
 * in three general stages: Ogg Physical Bitstream -> Ogg/FLAC Logical Bitstream -> FLAC Native Bitstream. dr_flac is architecured
 * in such a way that the core sections assume everything is delivered in native format. Therefore, for each encapsulation type
 * dr_flac is supporting there needs to be a layer sitting on top of the onRead and onSeek callbacks that ensures the bits read from
 * the physical Ogg bitstream are converted and delivered in native FLAC format. */
typedef struct
{
    drflac_read_proc onRead;    /* The original onRead callback from drflac_open() and family. */
    drflac_seek_proc onSeek;    /* The original onSeek callback from drflac_open() and family. */
    void* pUserData;            /* The user data passed on onRead and onSeek. This is the user data that was passed on drflac_open() and family. */
    drflac_uint64 currentBytePos;   /* The position of the byte we are sitting on in the physical byte stream. Used for efficient seeking. */
    drflac_uint64 firstBytePos;     /* The position of the first byte in the physical bitstream. Points to the start of the "OggS" identifier of the FLAC bos page. */
    drflac_uint32 serialNumber;     /* The serial number of the FLAC audio pages. This is determined by the initial header page that was read during initialization. */
    drflac_ogg_page_header bosPageHeader;   /* Used for seeking. */
    drflac_ogg_page_header currentPageHeader;
    drflac_uint32 bytesRemainingInPage;
    drflac_uint32 pageDataSize;
    drflac_uint8 pageData[DRFLAC_OGG_MAX_PAGE_SIZE];
} drflac_oggbs; /* oggbs = Ogg Bitstream */

static size_t drflac_oggbs__read_physical(drflac_oggbs* oggbs, void* bufferOut, size_t bytesToRead)
{
    size_t bytesActuallyRead = oggbs->onRead(oggbs->pUserData, bufferOut, bytesToRead);
    oggbs->currentBytePos += bytesActuallyRead;

    return bytesActuallyRead;
}

static drflac_bool32 drflac_oggbs__seek_physical(drflac_oggbs* oggbs, drflac_uint64 offset, drflac_seek_origin origin)
{
    if (origin == drflac_seek_origin_start)
    {
       if (offset <= 0x7FFFFFFF)
       {
          if (!oggbs->onSeek(oggbs->pUserData, (int)offset, drflac_seek_origin_start))
             return DRFLAC_FALSE;
          oggbs->currentBytePos = offset;

          return DRFLAC_TRUE;
       }
       else
       {
          if (!oggbs->onSeek(oggbs->pUserData, 0x7FFFFFFF, drflac_seek_origin_start))
             return DRFLAC_FALSE;
          oggbs->currentBytePos = offset;

          return drflac_oggbs__seek_physical(oggbs, offset - 0x7FFFFFFF, drflac_seek_origin_current);
       }
    }
    else
    {
        while (offset > 0x7FFFFFFF)
        {
           if (!oggbs->onSeek(oggbs->pUserData, 0x7FFFFFFF, drflac_seek_origin_current))
              return DRFLAC_FALSE;
           oggbs->currentBytePos += 0x7FFFFFFF;
           offset -= 0x7FFFFFFF;
        }

        if (!oggbs->onSeek(oggbs->pUserData, (int)offset, drflac_seek_origin_current)) /* <-- Safe cast thanks to the loop above. */
            return DRFLAC_FALSE;
        oggbs->currentBytePos += offset;

        return DRFLAC_TRUE;
    }
}

static drflac_bool32 drflac_oggbs__goto_next_page(drflac_oggbs* oggbs, drflac_ogg_crc_mismatch_recovery recoveryMethod)
{
    drflac_ogg_page_header header;
    for (;;) {
#ifndef DR_FLAC_NO_CRC
        drflac_uint32 actualCRC32;
#endif
        drflac_uint32 pageBodySize;
        drflac_uint32 crc32 = 0;
        drflac_uint32 bytesRead;
        if (drflac_ogg__read_page_header(oggbs->onRead, oggbs->pUserData, &header, &bytesRead, &crc32) != DRFLAC_SUCCESS)
            return DRFLAC_FALSE;
        oggbs->currentBytePos += bytesRead;

        pageBodySize = drflac_ogg__get_page_body_size(&header);
        if (pageBodySize > DRFLAC_OGG_MAX_PAGE_SIZE)
            continue;   /* Invalid page size. Assume it's corrupted and just move to the next page. */

        if (header.serialNumber != oggbs->serialNumber)
        {
            /* It's not a FLAC page. Skip it. */
            if (pageBodySize > 0 && !drflac_oggbs__seek_physical(oggbs, pageBodySize, drflac_seek_origin_current))
                return DRFLAC_FALSE;
            continue;
        }

        /* We need to read the entire page and then do a CRC check on it. If there's a CRC mismatch we need to skip this page. */
        if (drflac_oggbs__read_physical(oggbs, oggbs->pageData, pageBodySize) != pageBodySize)
            return DRFLAC_FALSE;
        oggbs->pageDataSize = pageBodySize;

#ifndef DR_FLAC_NO_CRC
        actualCRC32 = drflac_crc32_buffer(crc32, oggbs->pageData, oggbs->pageDataSize);
        if (actualCRC32 != header.checksum)
        {
           if (recoveryMethod == drflac_ogg_recover_on_crc_mismatch)
              continue;   /* CRC mismatch. Skip this page. */

           /* Even though we are failing on a CRC mismatch, we still want our stream to be in a good state. Therefore we
            * go to the next valid page to ensure we're in a good state, but return false to let the caller know that the
            * seek did not fully complete. */
           drflac_oggbs__goto_next_page(oggbs, drflac_ogg_recover_on_crc_mismatch);
           return DRFLAC_FALSE;
        }
#endif

        oggbs->currentPageHeader = header;
        oggbs->bytesRemainingInPage = pageBodySize;
        return DRFLAC_TRUE;
    }
}

/* Function below is unused at the moment, but I might be re-adding it later. */
#if 0
static drflac_uint8 drflac_oggbs__get_current_segment_index(drflac_oggbs* oggbs, drflac_uint8* pBytesRemainingInSeg)
{
    drflac_uint32 bytesConsumedInPage = drflac_ogg__get_page_body_size(&oggbs->currentPageHeader) - oggbs->bytesRemainingInPage;
    drflac_uint8 iSeg = 0;
    drflac_uint32 iByte = 0;
    while (iByte < bytesConsumedInPage)
    {
       drflac_uint8 segmentSize = oggbs->currentPageHeader.segmentTable[iSeg];
       if (iByte + segmentSize > bytesConsumedInPage)
          break;

       iSeg += 1;
       iByte += segmentSize;
    }

    *pBytesRemainingInSeg = oggbs->currentPageHeader.segmentTable[iSeg] - (drflac_uint8)(bytesConsumedInPage - iByte);
    return iSeg;
}

static drflac_bool32 drflac_oggbs__seek_to_next_packet(drflac_oggbs* oggbs)
{
    /* The current packet ends when we get to the segment with a lacing value of < 255 which is not at the end of a page. */
    for (;;) {
        drflac_bool32 atEndOfPage = DRFLAC_FALSE;

        drflac_uint8 bytesRemainingInSeg;
        drflac_uint8 iFirstSeg = drflac_oggbs__get_current_segment_index(oggbs, &bytesRemainingInSeg);

        drflac_uint32 bytesToEndOfPacketOrPage = bytesRemainingInSeg;
        for (drflac_uint8 iSeg = iFirstSeg; iSeg < oggbs->currentPageHeader.segmentCount; ++iSeg) {
            drflac_uint8 segmentSize = oggbs->currentPageHeader.segmentTable[iSeg];
            if (segmentSize < 255)
            {
                if (iSeg == oggbs->currentPageHeader.segmentCount-1)
                    atEndOfPage = DRFLAC_TRUE;

                break;
            }

            bytesToEndOfPacketOrPage += segmentSize;
        }

        /* At this point we will have found either the packet or the end of the page. If were at the end of the page we'll
         * want to load the next page and keep searching for the end of the packet. */
        drflac_oggbs__seek_physical(oggbs, bytesToEndOfPacketOrPage, drflac_seek_origin_current);
        oggbs->bytesRemainingInPage -= bytesToEndOfPacketOrPage;

        if (atEndOfPage)
        {
            /* We're potentially at the next packet, but we need to check the next page first to be sure because the packet may
             * straddle pages. */
            if (!drflac_oggbs__goto_next_page(oggbs))
                return DRFLAC_FALSE;

            /* If it's a fresh packet it most likely means we're at the next packet. */
            if ((oggbs->currentPageHeader.headerType & 0x01) == 0)
                return DRFLAC_TRUE;
        }
        else
        {
            /* We're at the next packet. */
            return DRFLAC_TRUE;
        }
    }
}

static drflac_bool32 drflac_oggbs__seek_to_next_frame(drflac_oggbs* oggbs)
{
    /* The bitstream should be sitting on the first byte just after the header of the frame.

     * What we're actually doing here is seeking to the start of the next packet. */
    return drflac_oggbs__seek_to_next_packet(oggbs);
}
#endif

static size_t drflac__on_read_ogg(void* pUserData, void* bufferOut, size_t bytesToRead)
{
    size_t bytesRead = 0;
    drflac_uint8* pRunningBufferOut = NULL;
    drflac_oggbs* oggbs = (drflac_oggbs*)pUserData;

    drflac_assert(oggbs != NULL);

    pRunningBufferOut = (drflac_uint8*)bufferOut;

    /* Reading is done page-by-page. If we've run out of bytes in the page we need to move to the next one. */
    while (bytesRead < bytesToRead)
    {
       size_t bytesRemainingToRead = bytesToRead - bytesRead;

       if (oggbs->bytesRemainingInPage >= bytesRemainingToRead) {
          drflac_copy_memory(pRunningBufferOut, oggbs->pageData + (oggbs->pageDataSize - oggbs->bytesRemainingInPage), bytesRemainingToRead);
          bytesRead += bytesRemainingToRead;
          oggbs->bytesRemainingInPage -= (drflac_uint32)bytesRemainingToRead;
          break;
       }

       /* If we get here it means some of the requested data is contained in the next pages. */
       if (oggbs->bytesRemainingInPage > 0)
       {
          drflac_copy_memory(pRunningBufferOut, oggbs->pageData + (oggbs->pageDataSize - oggbs->bytesRemainingInPage), oggbs->bytesRemainingInPage);
          bytesRead += oggbs->bytesRemainingInPage;
          pRunningBufferOut += oggbs->bytesRemainingInPage;
          oggbs->bytesRemainingInPage = 0;
       }

       drflac_assert(bytesRemainingToRead > 0);
       if (!drflac_oggbs__goto_next_page(oggbs, drflac_ogg_recover_on_crc_mismatch))
          break;  /* Failed to go to the next page. Might have simply hit the end of the stream. */
    }

    return bytesRead;
}

static drflac_bool32 drflac__on_seek_ogg(void* pUserData, int offset, drflac_seek_origin origin)
{
    int bytesSeeked = 0;
    drflac_oggbs* oggbs = (drflac_oggbs*)pUserData;

    drflac_assert(oggbs != NULL);
    drflac_assert(offset > 0 || (offset == 0 && origin == drflac_seek_origin_start));

    /* Seeking is always forward which makes things a lot simpler. */
    if (origin == drflac_seek_origin_start)
    {
       if (!drflac_oggbs__seek_physical(oggbs, (int)oggbs->firstBytePos, drflac_seek_origin_start))
          return DRFLAC_FALSE;

       if (!drflac_oggbs__goto_next_page(oggbs, drflac_ogg_fail_on_crc_mismatch))
          return DRFLAC_FALSE;

       return drflac__on_seek_ogg(pUserData, offset, drflac_seek_origin_current);
    }

    drflac_assert(origin == drflac_seek_origin_current);

    while (bytesSeeked < offset)
    {
       int bytesRemainingToSeek = offset - bytesSeeked;
       drflac_assert(bytesRemainingToSeek >= 0);

       if (oggbs->bytesRemainingInPage >= (size_t)bytesRemainingToSeek)
       {
          oggbs->bytesRemainingInPage -= bytesRemainingToSeek;
          break;
       }

       /* If we get here it means some of the requested data is contained in the next pages. */
       if (oggbs->bytesRemainingInPage > 0)
       {
          bytesSeeked += (int)oggbs->bytesRemainingInPage;
          oggbs->bytesRemainingInPage = 0;
       }

       drflac_assert(bytesRemainingToSeek > 0);

       /* Failed to go to the next page. We either hit the end of the stream or had a CRC mismatch. */
       if (!drflac_oggbs__goto_next_page(oggbs, drflac_ogg_fail_on_crc_mismatch))
          return DRFLAC_FALSE;
    }

    return DRFLAC_TRUE;
}

drflac_bool32 drflac_ogg__seek_to_sample(drflac* pFlac, drflac_uint64 sampleIndex)
{
   drflac_uint64 runningSampleCount;
   drflac_uint64 runningFrameBytePos;
   drflac_uint64 runningGranulePosition = 0;
   drflac_oggbs* oggbs = (drflac_oggbs*)pFlac->_oggbs;

   drflac_uint64 originalBytePos = oggbs->currentBytePos;   /* For recovery. */

   /* First seek to the first frame. */
   if (!drflac__seek_to_byte(&pFlac->bs, pFlac->firstFramePos))
      return DRFLAC_FALSE;
   oggbs->bytesRemainingInPage = 0;

   for (;;)
   {
      if (!drflac_oggbs__goto_next_page(oggbs, drflac_ogg_recover_on_crc_mismatch)) {
         drflac_oggbs__seek_physical(oggbs, originalBytePos, drflac_seek_origin_start);
         return DRFLAC_FALSE;   /* Never did find that sample... */
      }

      runningFrameBytePos = oggbs->currentBytePos - drflac_ogg__get_page_header_size(&oggbs->currentPageHeader) - oggbs->pageDataSize;
      if (oggbs->currentPageHeader.granulePosition*pFlac->channels >= sampleIndex)
         break; /* The sample is somewhere in the previous page. */

      /* At this point we know the sample is not in the previous page. It could possibly be in this page. For simplicity we
       * disregard any pages that do not begin a fresh packet. */
      if ((oggbs->currentPageHeader.headerType & 0x01) == 0)
      {    /* <-- Is it a fresh page? */
         if (oggbs->currentPageHeader.segmentTable[0] >= 2)
         {
            drflac_uint8 firstBytesInPage[2];
            firstBytesInPage[0] = oggbs->pageData[0];
            firstBytesInPage[1] = oggbs->pageData[1];

            if ((firstBytesInPage[0] == 0xFF) && (firstBytesInPage[1] & 0xFC) == 0xF8)    /* <-- Does the page begin with a frame's sync code? */
               runningGranulePosition = oggbs->currentPageHeader.granulePosition*pFlac->channels;

            continue;
         }
      }
   }


   /* We found the page that that is closest to the sample, so now we need to find it. The first thing to do is seek to the
    * start of that page. In the loop above we checked that it was a fresh page which means this page is also the start of
    * a new frame. This property means that after we've seeked to the page we can immediately start looping over frames until
    * we find the one containing the target sample. */
   if (!drflac_oggbs__seek_physical(oggbs, runningFrameBytePos, drflac_seek_origin_start))
      return DRFLAC_FALSE;
   if (!drflac_oggbs__goto_next_page(oggbs, drflac_ogg_recover_on_crc_mismatch))
      return DRFLAC_FALSE;

   /* At this point we'll be sitting on the first byte of the frame header of the first frame in the page. We just keep
    * looping over these frames until we find the one containing the sample we're after. */
   runningSampleCount = runningGranulePosition;
   for (;;)
   {
      drflac_uint64 sampleCountInThisFrame;
      drflac_uint64 firstSampleInFrame = 0;
      drflac_uint64 lastSampleInFrame = 0;
      /* There are two ways to find the sample and seek past irrelevant frames:
       *   1) Use the native FLAC decoder.
       *   2) Use Ogg's framing system.
       *
       * Both of these options have their own pros and cons. Using the native FLAC decoder is slower because it needs to
       * do a full decode of the frame. Using Ogg's framing system is faster, but more complicated and involves some code
       * duplication for the decoding of frame headers.
       *
       * Another thing to consider is that using the Ogg framing system will perform direct seeking of the physical Ogg
       * bitstream. This is important to consider because it means we cannot read data from the drflac_bs object using the
       * standard drflac__*() APIs because that will read in extra data for it's own internal caching which in turn breaks
       * the positioning of the read pointer of the physical Ogg bitstream. Therefore, anything that would normally be read
       * using the native FLAC decoding APIs, such as drflac__read_next_frame_header(), need to be re-implemented so as to
       * avoid the use of the drflac_bs object.
       *
       * Considering these issues, I have decided to use the slower native FLAC decoding method for the following reasons:
       *   1) Seeking is already partially accellerated using Ogg's paging system in the code block above.
       *   2) Seeking in an Ogg encapsulated FLAC stream is probably quite uncommon.
       *   3) Simplicity.
       */
      if (!drflac__read_next_frame_header(&pFlac->bs, pFlac->bitsPerSample, &pFlac->currentFrame.header))
         return DRFLAC_FALSE;

      drflac__get_current_frame_sample_range(pFlac, &firstSampleInFrame, &lastSampleInFrame);

      sampleCountInThisFrame = (lastSampleInFrame - firstSampleInFrame) + 1;
      if (sampleIndex < (runningSampleCount + sampleCountInThisFrame)) {
         /* The sample should be in this frame. We need to fully decode it, however if it's an invalid frame (a CRC mismatch), we need to pretend
          * it never existed and keep iterating. */
         drflac_result result = drflac__decode_frame(pFlac);
         if (result == DRFLAC_SUCCESS) {
            /* The frame is valid. We just need to skip over some samples to ensure it's sample-exact. */
            drflac_uint64 samplesToDecode = (size_t)(sampleIndex - runningSampleCount);    /* <-- Safe cast because the maximum number of samples in a frame is 65535. */
            if (samplesToDecode == 0)
               return DRFLAC_TRUE;
            return drflac_read_s32(pFlac, samplesToDecode, NULL) != 0;  /* <-- If this fails, something bad has happened (it should never fail). */
         }
         else
         {
            if (result == DRFLAC_CRC_MISMATCH)
               continue;   /* CRC mismatch. Pretend this frame never existed. */
            return DRFLAC_FALSE;
         }
      }
      else
      {
         /* It's not in this frame. We need to seek past the frame, but check if there was a CRC mismatch. If so, we pretend this
          * frame never existed and leave the running sample count untouched. */
         drflac_result result = drflac__seek_to_next_frame(pFlac);
         if (result == DRFLAC_SUCCESS)
            runningSampleCount += sampleCountInThisFrame;
         else
         {
            if (result == DRFLAC_CRC_MISMATCH)
               continue;   /* CRC mismatch. Pretend this frame never existed. */
            return DRFLAC_FALSE;
         }
      }
   }
}


drflac_bool32 drflac__init_private__ogg(drflac_init_info* pInit, drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, void* pUserData, void* pUserDataMD, drflac_bool32 relaxed)
{
    /* We'll get here if the first 4 bytes of the stream were the OggS capture pattern, however it doesn't necessarily mean the
     * stream includes FLAC encoded audio. To check for this we need to scan the beginning-of-stream page markers and check if
     * any match the FLAC specification. Important to keep in mind that the stream may be multiplexed. */
    drflac_ogg_page_header header;

    drflac_uint32 crc32 = DRFLAC_OGG_CAPTURE_PATTERN_CRC32;
    drflac_uint32 bytesRead = 0;
    /* Pre: The bit stream should be sitting just past the 4-byte OggS capture pattern. */
    (void)relaxed;

    pInit->container = drflac_container_ogg;
    pInit->oggFirstBytePos = 0;

    if (drflac_ogg__read_page_header_after_capture_pattern(onRead, pUserData, &header, &bytesRead, &crc32) != DRFLAC_SUCCESS)
        return DRFLAC_FALSE;
    pInit->runningFilePos += bytesRead;

    for (;;)
    {
       int pageBodySize;
        /* Break if we're past the beginning of stream page. */
        if ((header.headerType & 0x02) == 0)
            return DRFLAC_FALSE;

        /* Check if it's a FLAC header. */
        pageBodySize = drflac_ogg__get_page_body_size(&header);
        if (pageBodySize == 51)
        {
           /* 51 = the lacing value of the FLAC header packet.
            * It could be a FLAC page... */
           drflac_uint32 bytesRemainingInPage = pageBodySize;

           drflac_uint8 packetType;
           if (onRead(pUserData, &packetType, 1) != 1)
              return DRFLAC_FALSE;

           bytesRemainingInPage -= 1;
           if (packetType == 0x7F)
           {
              /* Increasingly more likely to be a FLAC page... */
              drflac_uint8 sig[4];
              if (onRead(pUserData, sig, 4) != 4)
                 return DRFLAC_FALSE;

              bytesRemainingInPage -= 4;
              if (sig[0] == 'F' && sig[1] == 'L' && sig[2] == 'A' && sig[3] == 'C') {
                 /* Almost certainly a FLAC page... */
                 drflac_uint8 mappingVersion[2];
                 if (onRead(pUserData, mappingVersion, 2) != 2)
                    return DRFLAC_FALSE;

                 if (mappingVersion[0] != 1)
                    return DRFLAC_FALSE;   /* Only supporting version 1.x of the Ogg mapping. */

                 /* The next 2 bytes are the non-audio packets, not including this one. We don't care about this because we're going to
                  * be handling it in a generic way based on the serial number and packet types. */
                 if (!onSeek(pUserData, 2, drflac_seek_origin_current))
                    return DRFLAC_FALSE;

                 /* Expecting the native FLAC signature "fLaC". */
                 if (onRead(pUserData, sig, 4) != 4)
                    return DRFLAC_FALSE;

                 if (sig[0] == 'f' && sig[1] == 'L' && sig[2] == 'a' && sig[3] == 'C')
                 {
                    drflac_streaminfo streaminfo;
                    /* The remaining data in the page should be the STREAMINFO block. */
                    drflac_uint8 isLastBlock = 0;
                    drflac_uint8 blockType   = 0;
                    drflac_uint32 blockSize  = 0;
                    if (!drflac__read_and_decode_block_header(onRead, pUserData, &isLastBlock, &blockType, &blockSize))
                       return DRFLAC_FALSE;

                    if (blockType != DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO || blockSize != 34)
                       return DRFLAC_FALSE;    /* Invalid block type. First block must be the STREAMINFO block. */

                    if (drflac__read_streaminfo(onRead, pUserData, &streaminfo)) {
                       /* Success! */
                       pInit->hasStreamInfoBlock = DRFLAC_TRUE;
                       pInit->sampleRate         = streaminfo.sampleRate;
                       pInit->channels           = streaminfo.channels;
                       pInit->bitsPerSample      = streaminfo.bitsPerSample;
                       pInit->totalSampleCount   = streaminfo.totalSampleCount;
                       pInit->maxBlockSize       = streaminfo.maxBlockSize;
                       pInit->hasMetadataBlocks  = !isLastBlock;

                       if (onMeta) {
                          drflac_metadata metadata;
                          metadata.type = DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO;
                          metadata.pRawData = NULL;
                          metadata.rawDataSize = 0;
                          metadata.data.streaminfo = streaminfo;
                          onMeta(pUserDataMD, &metadata);
                       }

                       pInit->runningFilePos  += pageBodySize;
                       pInit->oggFirstBytePos  = pInit->runningFilePos - 79;   /* Subtracting 79 will place us right on top of the "OggS" identifier of the FLAC bos page. */
                       pInit->oggSerial        = header.serialNumber;
                       pInit->oggBosHeader     = header;
                       break;
                    }
                    else
                    {
                       /* Failed to read STREAMINFO block. Aww, so close... */
                       return DRFLAC_FALSE;
                    }
                 }
                 else
                 {
                    /* Invalid file. */
                    return DRFLAC_FALSE;
                 }
              }
              else
              {
                 /* Not a FLAC header. Skip it. */
                 if (!onSeek(pUserData, bytesRemainingInPage, drflac_seek_origin_current))
                    return DRFLAC_FALSE;
              }
           }
           else
           {
              /* Not a FLAC header. Seek past the entire page and move on to the next. */
              if (!onSeek(pUserData, bytesRemainingInPage, drflac_seek_origin_current))
                 return DRFLAC_FALSE;
           }
        }
        else
        {
           if (!onSeek(pUserData, pageBodySize, drflac_seek_origin_current))
              return DRFLAC_FALSE;
        }

        pInit->runningFilePos += pageBodySize;

        /* Read the header of the next page. */
        if (drflac_ogg__read_page_header(onRead, pUserData, &header, &bytesRead, &crc32) != DRFLAC_SUCCESS)
            return DRFLAC_FALSE;
        pInit->runningFilePos += bytesRead;
    }


    /* If we get here it means we found a FLAC audio stream. We should be sitting on the first byte of the header of the next page. The next
     * packets in the FLAC logical stream contain the metadata. The only thing left to do in the initialiation phase for Ogg is to create the
     * Ogg bistream object. */
    pInit->hasMetadataBlocks = DRFLAC_TRUE;    /* <-- Always have at least VORBIS_COMMENT metadata block. */
    return DRFLAC_TRUE;
}
#endif

drflac_bool32 drflac__init_private(drflac_init_info* pInit, drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, drflac_container container, void* pUserData, void* pUserDataMD)
{
    drflac_uint8 id[4];
    drflac_bool32 relaxed;

    if (pInit == NULL || onRead == NULL || onSeek == NULL)
        return DRFLAC_FALSE;

    drflac_zero_memory(pInit, sizeof(*pInit));
    pInit->onRead       = onRead;
    pInit->onSeek       = onSeek;
    pInit->onMeta       = onMeta;
    pInit->container    = container;
    pInit->pUserData    = pUserData;
    pInit->pUserDataMD  = pUserDataMD;

    pInit->bs.onRead    = onRead;
    pInit->bs.onSeek    = onSeek;
    pInit->bs.pUserData = pUserData;
    drflac__reset_cache(&pInit->bs);


    /* If the container is explicitly defined then we can try opening in relaxed mode. */
    relaxed = container != drflac_container_unknown;

    /* Skip over any ID3 tags. */
    for (;;)
    {
       if (onRead(pUserData, id, 4) != 4)
          return DRFLAC_FALSE;    /* Ran out of data. */
       pInit->runningFilePos += 4;

       if (id[0] == 'I' && id[1] == 'D' && id[2] == '3')
       {
          drflac_uint8 flags;
          drflac_uint32 headerSize;
          drflac_uint8 header[6];

          if (onRead(pUserData, header, 6) != 6)
             return DRFLAC_FALSE;    /* Ran out of data. */
          pInit->runningFilePos += 6;

          flags = header[1];
          drflac_copy_memory(&headerSize, header+2, 4);
          headerSize = drflac__unsynchsafe_32(drflac__be2host_32(headerSize));
          if (flags & 0x10)
             headerSize += 10;

          if (!onSeek(pUserData, headerSize, drflac_seek_origin_current))
             return DRFLAC_FALSE;    /* Failed to seek past the tag. */
          pInit->runningFilePos += headerSize;
       }
       else
          break;
    }

    if (id[0] == 'f' && id[1] == 'L' && id[2] == 'a' && id[3] == 'C') {
        return drflac__init_private__native(pInit, onRead, onSeek, onMeta, pUserData, pUserDataMD, relaxed);
    }
#ifndef DR_FLAC_NO_OGG
    if (id[0] == 'O' && id[1] == 'g' && id[2] == 'g' && id[3] == 'S') {
        return drflac__init_private__ogg(pInit, onRead, onSeek, onMeta, pUserData, pUserDataMD, relaxed);
    }
#endif

    /* If we get here it means we likely don't have a header. Try opening in relaxed mode, if applicable. */
    if (relaxed)
    {
       if (container == drflac_container_native)
          return drflac__init_private__native(pInit, onRead, onSeek, onMeta, pUserData, pUserDataMD, relaxed);
#ifndef DR_FLAC_NO_OGG
       if (container == drflac_container_ogg)
          return drflac__init_private__ogg(pInit, onRead, onSeek, onMeta, pUserData, pUserDataMD, relaxed);
#endif
    }

    /* Unsupported container. */
    return DRFLAC_FALSE;
}

void drflac__init_from_info(drflac* pFlac, drflac_init_info* pInit)
{
    drflac_assert(pFlac != NULL);
    drflac_assert(pInit != NULL);

    drflac_zero_memory(pFlac, sizeof(*pFlac));
    pFlac->bs               = pInit->bs;
    pFlac->onMeta           = pInit->onMeta;
    pFlac->pUserDataMD      = pInit->pUserDataMD;
    pFlac->maxBlockSize     = pInit->maxBlockSize;
    pFlac->sampleRate       = pInit->sampleRate;
    pFlac->channels         = (drflac_uint8)pInit->channels;
    pFlac->bitsPerSample    = (drflac_uint8)pInit->bitsPerSample;
    pFlac->totalSampleCount = pInit->totalSampleCount;
    pFlac->container        = pInit->container;
}

drflac* drflac_open_with_metadata_private(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, drflac_container container, void* pUserData, void* pUserDataMD)
{
    drflac_init_info init;
    drflac* pFlac;
    drflac_uint32 decodedSamplesAllocationSize;
    drflac_uint32 allocationSize;
    drflac_uint32 wholeSIMDVectorCountPerChannel;

#ifndef DRFLAC_NO_CPUID
    /* CPU support first. */
    drflac__init_cpu_caps();
#endif

    if (!drflac__init_private(&init, onRead, onSeek, onMeta, container, pUserData, pUserDataMD))
        return NULL;

    /* The size of the allocation for the drflac object needs to be large enough to fit the following:
     *   1) The main members of the drflac structure
     *   2) A block of memory large enough to store the decoded samples of the largest frame in the stream
     *   3) If the container is Ogg, a drflac_oggbs object
     *
     * The complicated part of the allocation is making sure there's enough room the decoded samples, taking into consideration
     * the different SIMD instruction sets.
     */
    allocationSize = sizeof(drflac);

    /* The allocation size for decoded frames depends on the number of 32-bit integers that fit inside the largest SIMD vector
     * we are supporting. */
    if ((init.maxBlockSize % (DRFLAC_MAX_SIMD_VECTOR_SIZE / sizeof(drflac_int32))) == 0) {
        wholeSIMDVectorCountPerChannel = (init.maxBlockSize / (DRFLAC_MAX_SIMD_VECTOR_SIZE / sizeof(drflac_int32)));
    } else {
        wholeSIMDVectorCountPerChannel = (init.maxBlockSize / (DRFLAC_MAX_SIMD_VECTOR_SIZE / sizeof(drflac_int32))) + 1;
    }

    decodedSamplesAllocationSize = wholeSIMDVectorCountPerChannel * DRFLAC_MAX_SIMD_VECTOR_SIZE * init.channels;

    allocationSize += decodedSamplesAllocationSize;
    allocationSize += DRFLAC_MAX_SIMD_VECTOR_SIZE;  /* Allocate extra bytes to ensure we have enough for alignment. */

#ifndef DR_FLAC_NO_OGG
    /* There's additional data required for Ogg streams. */
    if (init.container == drflac_container_ogg)
        allocationSize += sizeof(drflac_oggbs);
#endif

    pFlac = (drflac*)DRFLAC_MALLOC(allocationSize);
    drflac__init_from_info(pFlac, &init);
    pFlac->pDecodedSamples = (drflac_int32*)drflac_align((size_t)pFlac->pExtraData, DRFLAC_MAX_SIMD_VECTOR_SIZE);

#ifndef DR_FLAC_NO_OGG
    if (init.container == drflac_container_ogg) {
        drflac_oggbs* oggbs = (drflac_oggbs*)((drflac_uint8*)pFlac->pDecodedSamples + decodedSamplesAllocationSize);
        oggbs->onRead = onRead;
        oggbs->onSeek = onSeek;
        oggbs->pUserData = pUserData;
        oggbs->currentBytePos = init.oggFirstBytePos;
        oggbs->firstBytePos = init.oggFirstBytePos;
        oggbs->serialNumber = init.oggSerial;
        oggbs->bosPageHeader = init.oggBosHeader;
        oggbs->bytesRemainingInPage = 0;

        /* The Ogg bistream needs to be layered on top of the original bitstream. */
        pFlac->bs.onRead = drflac__on_read_ogg;
        pFlac->bs.onSeek = drflac__on_seek_ogg;
        pFlac->bs.pUserData = (void*)oggbs;
        pFlac->_oggbs = (void*)oggbs;
    }
#endif

    /* Decode metadata before returning. */
    if (init.hasMetadataBlocks)
    {
        if (!drflac__read_and_decode_metadata(pFlac))
        {
            DRFLAC_FREE(pFlac);
            return NULL;
        }
    }

    /* If we get here, but don't have a STREAMINFO block, it means we've opened the stream in relaxed mode and need to decode
     * the first frame. */
    if (!init.hasStreamInfoBlock)
    {
        pFlac->currentFrame.header = init.firstFrameHeader;
        do
        {
           drflac_result result = drflac__decode_frame(pFlac);
           if (result == DRFLAC_SUCCESS)
              break;

           if (result == DRFLAC_CRC_MISMATCH)
           {
              if (drflac__read_next_frame_header(&pFlac->bs, pFlac->bitsPerSample, &pFlac->currentFrame.header))
                 continue;
           }
           DRFLAC_FREE(pFlac);
           return NULL;
        } while (1);
    }

    return pFlac;
}

#ifndef DR_FLAC_NO_STDIO
typedef void* drflac_file;

#if defined(DR_FLAC_NO_WIN32_IO) || !defined(_WIN32)
#include <stdio.h>

static size_t drflac__on_read_stdio(void* pUserData, void* bufferOut, size_t bytesToRead)
{
    return fread(bufferOut, 1, bytesToRead, (FILE*)pUserData);
}

static drflac_bool32 drflac__on_seek_stdio(void* pUserData, int offset, drflac_seek_origin origin)
{
    drflac_assert(offset > 0 || (offset == 0 && origin == drflac_seek_origin_start));

    return fseek((FILE*)pUserData, offset, (origin == drflac_seek_origin_current) ? SEEK_CUR : SEEK_SET) == 0;
}

static drflac_file drflac__open_file_handle(const char* filename)
{
    FILE* pFile;
#ifdef _MSC_VER
    if (fopen_s(&pFile, filename, "rb") != 0) {
        return NULL;
    }
#else
    pFile = fopen(filename, "rb");
    if (pFile == NULL) {
        return NULL;
    }
#endif

    return (drflac_file)pFile;
}

static void drflac__close_file_handle(drflac_file file)
{
    fclose((FILE*)file);
}
#else
#include <windows.h>

/* This doesn't seem to be defined for VC6. */
#ifndef INVALID_SET_FILE_POINTER
#define INVALID_SET_FILE_POINTER ((DWORD)-1)
#endif

static size_t drflac__on_read_stdio(void* pUserData, void* bufferOut, size_t bytesToRead)
{
   DWORD bytesRead;

   drflac_assert(bytesToRead < 0xFFFFFFFF);   /* dr_flac will never request huge amounts of data at a time. This is a safe assertion. */

   ReadFile((HANDLE)pUserData, bufferOut, (DWORD)bytesToRead, &bytesRead, NULL);

   return (size_t)bytesRead;
}

static drflac_bool32 drflac__on_seek_stdio(void* pUserData, int offset, drflac_seek_origin origin)
{
    drflac_assert(offset > 0 || (offset == 0 && origin == drflac_seek_origin_start));

    return SetFilePointer((HANDLE)pUserData, offset, NULL, (origin == drflac_seek_origin_current) ? FILE_CURRENT : FILE_BEGIN) != INVALID_SET_FILE_POINTER;
}

static drflac_file drflac__open_file_handle(const char* filename)
{
    HANDLE hFile = CreateFileA(filename, FILE_GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
        return NULL;
    }

    return (drflac_file)hFile;
}

static void drflac__close_file_handle(drflac_file file)
{
    CloseHandle((HANDLE)file);
}
#endif


drflac* drflac_open_file(const char* filename)
{
    drflac_file file = drflac__open_file_handle(filename);
    if (file == NULL) {
        return NULL;
    }

    drflac* pFlac = drflac_open(drflac__on_read_stdio, drflac__on_seek_stdio, (void*)file);
    if (pFlac == NULL) {
        drflac__close_file_handle(file);
        return NULL;
    }

    return pFlac;
}

drflac* drflac_open_file_with_metadata(const char* filename, drflac_meta_proc onMeta, void* pUserData)
{
    drflac_file file = drflac__open_file_handle(filename);
    if (file == NULL) {
        return NULL;
    }

    drflac* pFlac = drflac_open_with_metadata_private(drflac__on_read_stdio, drflac__on_seek_stdio, onMeta, drflac_container_unknown, (void*)file, pUserData);
    if (pFlac == NULL) {
        drflac__close_file_handle(file);
        return pFlac;
    }

    return pFlac;
}
#endif  /* DR_FLAC_NO_STDIO */

static size_t drflac__on_read_memory(void* pUserData, void* bufferOut, size_t bytesToRead)
{
   size_t bytesRemaining;
   drflac__memory_stream* memoryStream = (drflac__memory_stream*)pUserData;
   drflac_assert(memoryStream != NULL);
   drflac_assert(memoryStream->dataSize >= memoryStream->currentReadPos);

   bytesRemaining = memoryStream->dataSize - memoryStream->currentReadPos;
   if (bytesToRead > bytesRemaining)
      bytesToRead = bytesRemaining;

   if (bytesToRead > 0)
   {
      drflac_copy_memory(bufferOut, memoryStream->data + memoryStream->currentReadPos, bytesToRead);
      memoryStream->currentReadPos += bytesToRead;
   }

   return bytesToRead;
}

static drflac_bool32 drflac__on_seek_memory(void* pUserData, int offset, drflac_seek_origin origin)
{
    drflac__memory_stream* memoryStream = (drflac__memory_stream*)pUserData;
    drflac_assert(memoryStream != NULL);
    drflac_assert(offset > 0 || (offset == 0 && origin == drflac_seek_origin_start));

    if (origin == drflac_seek_origin_current)
    {
        if (memoryStream->currentReadPos + offset <= memoryStream->dataSize)
            memoryStream->currentReadPos += offset;
        else
            memoryStream->currentReadPos = memoryStream->dataSize;  /* Trying to seek too far forward. */
    } else {
        if ((drflac_uint32)offset <= memoryStream->dataSize) {
            memoryStream->currentReadPos = offset;
        } else {
            memoryStream->currentReadPos = memoryStream->dataSize;  /* Trying to seek too far forward. */
        }
    }

    return DRFLAC_TRUE;
}

drflac* drflac_open_memory(const void* data, size_t dataSize)
{
    drflac__memory_stream memoryStream;
    drflac* pFlac;

    memoryStream.data = (const unsigned char*)data;
    memoryStream.dataSize = dataSize;
    memoryStream.currentReadPos = 0;
    pFlac = drflac_open(drflac__on_read_memory, drflac__on_seek_memory, &memoryStream);
    if (pFlac == NULL)
        return NULL;

    pFlac->memoryStream = memoryStream;

    /* This is an awful hack... */
#ifndef DR_FLAC_NO_OGG
    if (pFlac->container == drflac_container_ogg)
    {
        drflac_oggbs* oggbs = (drflac_oggbs*)pFlac->_oggbs;
        oggbs->pUserData = &pFlac->memoryStream;
    }
    else
#endif
    {
        pFlac->bs.pUserData = &pFlac->memoryStream;
    }

    return pFlac;
}

drflac* drflac_open_memory_with_metadata(const void* data, size_t dataSize, drflac_meta_proc onMeta, void* pUserData)
{
    drflac__memory_stream memoryStream;
    drflac* pFlac;

    memoryStream.data = (const unsigned char*)data;
    memoryStream.dataSize = dataSize;
    memoryStream.currentReadPos = 0;

    pFlac = drflac_open_with_metadata_private(drflac__on_read_memory, drflac__on_seek_memory, onMeta, drflac_container_unknown, &memoryStream, pUserData);
    if (pFlac == NULL)
        return NULL;

    pFlac->memoryStream = memoryStream;

    /* This is an awful hack... */
#ifndef DR_FLAC_NO_OGG
    if (pFlac->container == drflac_container_ogg)
    {
        drflac_oggbs* oggbs = (drflac_oggbs*)pFlac->_oggbs;
        oggbs->pUserData = &pFlac->memoryStream;
    }
    else
#endif
    {
        pFlac->bs.pUserData = &pFlac->memoryStream;
    }

    return pFlac;
}



drflac* drflac_open(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData)
{
    return drflac_open_with_metadata_private(onRead, onSeek, NULL, drflac_container_unknown, pUserData, pUserData);
}
drflac* drflac_open_relaxed(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_container container, void* pUserData)
{
    return drflac_open_with_metadata_private(onRead, onSeek, NULL, container, pUserData, pUserData);
}

drflac* drflac_open_with_metadata(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, void* pUserData)
{
    return drflac_open_with_metadata_private(onRead, onSeek, onMeta, drflac_container_unknown, pUserData, pUserData);
}
drflac* drflac_open_with_metadata_relaxed(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, drflac_container container, void* pUserData)
{
    return drflac_open_with_metadata_private(onRead, onSeek, onMeta, container, pUserData, pUserData);
}

void drflac_close(drflac* pFlac)
{
    if (pFlac == NULL) {
        return;
    }

#ifndef DR_FLAC_NO_STDIO
    /* If we opened the file with drflac_open_file() we will want to close the file handle. We can know whether or not drflac_open_file()
     * was used by looking at the callbacks. */
    if (pFlac->bs.onRead == drflac__on_read_stdio)
        drflac__close_file_handle((drflac_file)pFlac->bs.pUserData);

#ifndef DR_FLAC_NO_OGG
    /* Need to clean up Ogg streams a bit differently due to the way the bit streaming is chained. */
    if (pFlac->container == drflac_container_ogg)
    {
       drflac_assert(pFlac->bs.onRead == drflac__on_read_ogg);
       drflac_oggbs* oggbs = (drflac_oggbs*)pFlac->_oggbs;
       if (oggbs->onRead == drflac__on_read_stdio)
          drflac__close_file_handle((drflac_file)oggbs->pUserData);
    }
#endif
#endif

    DRFLAC_FREE(pFlac);
}

drflac_uint64 drflac__read_s32__misaligned(drflac* pFlac, drflac_uint64 samplesToRead, drflac_int32* bufferOut)
{
    drflac_uint64 samplesRead = 0;
    unsigned int channelCount = drflac__get_channel_count_from_channel_assignment(pFlac->currentFrame.header.channelAssignment);

    /* We should never be calling this when the number of samples to read is >= the sample count. */
    drflac_assert(samplesToRead < channelCount);
    drflac_assert(pFlac->currentFrame.samplesRemaining > 0 && samplesToRead <= pFlac->currentFrame.samplesRemaining);

    while (samplesToRead > 0)
    {
       drflac_uint64 totalSamplesInFrame = pFlac->currentFrame.header.blockSize * channelCount;
       drflac_uint64 samplesReadFromFrameSoFar = totalSamplesInFrame - pFlac->currentFrame.samplesRemaining;
       drflac_uint64 channelIndex = samplesReadFromFrameSoFar % channelCount;

       drflac_uint64 nextSampleInFrame = samplesReadFromFrameSoFar / channelCount;

       int decodedSample = 0;
       switch (pFlac->currentFrame.header.channelAssignment)
       {
          case DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE:
             {
                if (channelIndex == 0) {
                   decodedSample = pFlac->currentFrame.subframes[channelIndex].pDecodedSamples[nextSampleInFrame];
                } else {
                   int side = pFlac->currentFrame.subframes[channelIndex + 0].pDecodedSamples[nextSampleInFrame];
                   int left = pFlac->currentFrame.subframes[channelIndex - 1].pDecodedSamples[nextSampleInFrame];
                   decodedSample = left - side;
                }
             } break;

          case DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE:
             {
                if (channelIndex == 0) {
                   int side  = pFlac->currentFrame.subframes[channelIndex + 0].pDecodedSamples[nextSampleInFrame];
                   int right = pFlac->currentFrame.subframes[channelIndex + 1].pDecodedSamples[nextSampleInFrame];
                   decodedSample = side + right;
                } else {
                   decodedSample = pFlac->currentFrame.subframes[channelIndex].pDecodedSamples[nextSampleInFrame];
                }
             } break;

          case DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE:
             {
                int mid;
                int side;
                if (channelIndex == 0) {
                   mid  = pFlac->currentFrame.subframes[channelIndex + 0].pDecodedSamples[nextSampleInFrame];
                   side = pFlac->currentFrame.subframes[channelIndex + 1].pDecodedSamples[nextSampleInFrame];

                   mid = (((unsigned int)mid) << 1) | (side & 0x01);
                   decodedSample = (mid + side) >> 1;
                } else {
                   mid  = pFlac->currentFrame.subframes[channelIndex - 1].pDecodedSamples[nextSampleInFrame];
                   side = pFlac->currentFrame.subframes[channelIndex + 0].pDecodedSamples[nextSampleInFrame];

                   mid = (((unsigned int)mid) << 1) | (side & 0x01);
                   decodedSample = (mid - side) >> 1;
                }
             } break;

          case DRFLAC_CHANNEL_ASSIGNMENT_INDEPENDENT:
          default:
             {
                decodedSample = pFlac->currentFrame.subframes[channelIndex].pDecodedSamples[nextSampleInFrame];
             } break;
       }


       decodedSample <<= ((32 - pFlac->bitsPerSample) + pFlac->currentFrame.subframes[channelIndex].wastedBitsPerSample);

       if (bufferOut) {
          *bufferOut++ = decodedSample;
       }

       samplesRead += 1;
       pFlac->currentFrame.samplesRemaining -= 1;
       samplesToRead -= 1;
    }

    return samplesRead;
}

drflac_uint64 drflac__seek_forward_by_samples(drflac* pFlac, drflac_uint64 samplesToRead)
{
    drflac_uint64 samplesRead = 0;
    while (samplesToRead > 0) {
        if (pFlac->currentFrame.samplesRemaining == 0)
        {
            if (!drflac__read_and_decode_next_frame(pFlac))
                break;  /* Couldn't read the next frame, so just break from the loop and return. */
        }
        else
        {
            samplesRead += 1;
            pFlac->currentFrame.samplesRemaining -= 1;
            samplesToRead -= 1;
        }
    }

    return samplesRead;
}

drflac_uint64 drflac_read_s32(drflac* pFlac, drflac_uint64 samplesToRead, drflac_int32* bufferOut)
{
    drflac_uint64 samplesRead = 0;
    /* Note that <bufferOut> is allowed to be null, in which case this will be treated as something like a seek. */
    if (pFlac == NULL || samplesToRead == 0)
        return 0;

    if (bufferOut == NULL)
        return drflac__seek_forward_by_samples(pFlac, samplesToRead);

    while (samplesToRead > 0)
    {
       /* If we've run out of samples in this frame, go to the next. */
       if (pFlac->currentFrame.samplesRemaining == 0)
       {
          if (!drflac__read_and_decode_next_frame(pFlac))
             break;  /* Couldn't read the next frame, so just break from the loop and return. */
       }
       else
       {
          drflac_uint64 alignedSamplesRead;
          drflac_uint64 alignedSampleCountPerChannel;
          drflac_uint64 firstAlignedSampleInFrame;
          unsigned int unusedBitsPerSample;
          /* Here is where we grab the samples and interleave them. */
          unsigned int channelCount = drflac__get_channel_count_from_channel_assignment(pFlac->currentFrame.header.channelAssignment);
          drflac_uint64 totalSamplesInFrame = pFlac->currentFrame.header.blockSize * channelCount;
          drflac_uint64 samplesReadFromFrameSoFar = totalSamplesInFrame - pFlac->currentFrame.samplesRemaining;
          drflac_uint64 misalignedSampleCount = samplesReadFromFrameSoFar % channelCount;
          if (misalignedSampleCount > 0)
          {
             drflac_uint64 misalignedSamplesRead = drflac__read_s32__misaligned(pFlac, misalignedSampleCount, bufferOut);
             samplesRead   += misalignedSamplesRead;
             samplesReadFromFrameSoFar += misalignedSamplesRead;
             bufferOut     += misalignedSamplesRead;
             samplesToRead -= misalignedSamplesRead;
          }

          alignedSampleCountPerChannel = samplesToRead / channelCount;
          if (alignedSampleCountPerChannel > pFlac->currentFrame.samplesRemaining / channelCount)
             alignedSampleCountPerChannel = pFlac->currentFrame.samplesRemaining / channelCount;

          firstAlignedSampleInFrame = samplesReadFromFrameSoFar / channelCount;
          unusedBitsPerSample = 32 - pFlac->bitsPerSample;

          switch (pFlac->currentFrame.header.channelAssignment)
          {
             case DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE:
                {
                   drflac_uint64 i;
                   const drflac_int32* pDecodedSamples0 = pFlac->currentFrame.subframes[0].pDecodedSamples + firstAlignedSampleInFrame;
                   const drflac_int32* pDecodedSamples1 = pFlac->currentFrame.subframes[1].pDecodedSamples + firstAlignedSampleInFrame;

                   for (i = 0; i < alignedSampleCountPerChannel; ++i) {
                      int left  = pDecodedSamples0[i];
                      int side  = pDecodedSamples1[i];
                      int right = left - side;

                      bufferOut[i*2+0] = left  << (unusedBitsPerSample + pFlac->currentFrame.subframes[0].wastedBitsPerSample);
                      bufferOut[i*2+1] = right << (unusedBitsPerSample + pFlac->currentFrame.subframes[1].wastedBitsPerSample);
                   }
                } break;

             case DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE:
                {
                   drflac_uint64 i;
                   const drflac_int32* pDecodedSamples0 = pFlac->currentFrame.subframes[0].pDecodedSamples + firstAlignedSampleInFrame;
                   const drflac_int32* pDecodedSamples1 = pFlac->currentFrame.subframes[1].pDecodedSamples + firstAlignedSampleInFrame;

                   for (i = 0; i < alignedSampleCountPerChannel; ++i) {
                      int side  = pDecodedSamples0[i];
                      int right = pDecodedSamples1[i];
                      int left  = right + side;

                      bufferOut[i*2+0] = left  << (unusedBitsPerSample + pFlac->currentFrame.subframes[0].wastedBitsPerSample);
                      bufferOut[i*2+1] = right << (unusedBitsPerSample + pFlac->currentFrame.subframes[1].wastedBitsPerSample);
                   }
                } break;

             case DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE:
                {
                   drflac_uint64 i;
                   const drflac_int32* pDecodedSamples0 = pFlac->currentFrame.subframes[0].pDecodedSamples + firstAlignedSampleInFrame;
                   const drflac_int32* pDecodedSamples1 = pFlac->currentFrame.subframes[1].pDecodedSamples + firstAlignedSampleInFrame;

                   for (i = 0; i < alignedSampleCountPerChannel; ++i) {
                      int side = pDecodedSamples1[i];
                      int mid  = (((drflac_uint32)pDecodedSamples0[i]) << 1) | (side & 0x01);

                      bufferOut[i*2+0] = ((mid + side) >> 1) << (unusedBitsPerSample + pFlac->currentFrame.subframes[0].wastedBitsPerSample);
                      bufferOut[i*2+1] = ((mid - side) >> 1) << (unusedBitsPerSample + pFlac->currentFrame.subframes[1].wastedBitsPerSample);
                   }
                } break;

             case DRFLAC_CHANNEL_ASSIGNMENT_INDEPENDENT:
             default:
                {
                   if (pFlac->currentFrame.header.channelAssignment == 1) /* 1 = Stereo */
                   {
                      drflac_uint64 i;
                      /* Stereo optimized inner loop unroll. */
                      const drflac_int32* pDecodedSamples0 = pFlac->currentFrame.subframes[0].pDecodedSamples + firstAlignedSampleInFrame;
                      const drflac_int32* pDecodedSamples1 = pFlac->currentFrame.subframes[1].pDecodedSamples + firstAlignedSampleInFrame;

                      for (i = 0; i < alignedSampleCountPerChannel; ++i) {
                         bufferOut[i*2+0] = pDecodedSamples0[i] << (unusedBitsPerSample + pFlac->currentFrame.subframes[0].wastedBitsPerSample);
                         bufferOut[i*2+1] = pDecodedSamples1[i] << (unusedBitsPerSample + pFlac->currentFrame.subframes[1].wastedBitsPerSample);
                      }
                   }
                   else
                   {
                      drflac_uint64 i;

                      /* Generic interleaving. */
                      for (i = 0; i < alignedSampleCountPerChannel; ++i)
                      {
                         unsigned j;
                         for (j = 0; j < channelCount; ++j)
                         {
                            bufferOut[(i*channelCount)+j] = (pFlac->currentFrame.subframes[j].pDecodedSamples[firstAlignedSampleInFrame + i]) << (unusedBitsPerSample + pFlac->currentFrame.subframes[j].wastedBitsPerSample);
                         }
                      }
                   }
                } break;
          }

          alignedSamplesRead = alignedSampleCountPerChannel * channelCount;
          samplesRead   += alignedSamplesRead;
          samplesReadFromFrameSoFar += alignedSamplesRead;
          bufferOut     += alignedSamplesRead;
          samplesToRead -= alignedSamplesRead;
          pFlac->currentFrame.samplesRemaining -= (unsigned int)alignedSamplesRead;

          /* At this point we may still have some excess samples left to read. */
          if (samplesToRead > 0 && pFlac->currentFrame.samplesRemaining > 0) {
             drflac_uint64 excessSamplesRead = 0;
             if (samplesToRead < pFlac->currentFrame.samplesRemaining) {
                excessSamplesRead = drflac__read_s32__misaligned(pFlac, samplesToRead, bufferOut);
             } else {
                excessSamplesRead = drflac__read_s32__misaligned(pFlac, pFlac->currentFrame.samplesRemaining, bufferOut);
             }

             samplesRead   += excessSamplesRead;
             samplesReadFromFrameSoFar += excessSamplesRead;
             bufferOut     += excessSamplesRead;
             samplesToRead -= excessSamplesRead;
          }
       }
    }

    return samplesRead;
}

drflac_uint64 drflac_read_s16(drflac* pFlac, drflac_uint64 samplesToRead, drflac_int16* pBufferOut)
{
    /* This reads samples in 2 passes and can probably be optimized. */
    drflac_uint64 totalSamplesRead = 0;

    while (samplesToRead > 0)
    {
       drflac_uint64 i;
       drflac_int32 samples32[4096];
       drflac_uint64 samplesJustRead = drflac_read_s32(pFlac, (samplesToRead > 4096) ? 4096 : samplesToRead, samples32);
       if (samplesJustRead == 0)
          break;  /* Reached the end. */

       /* s32 -> s16 */
       for (i = 0; i < samplesJustRead; ++i)
          pBufferOut[i] = (drflac_int16)(samples32[i] >> 16);

       totalSamplesRead += samplesJustRead;
       samplesToRead -= samplesJustRead;
       pBufferOut += samplesJustRead;
    }

    return totalSamplesRead;
}

drflac_uint64 drflac_read_f32(drflac* pFlac, drflac_uint64 samplesToRead, float* pBufferOut)
{
    /* This reads samples in 2 passes and can probably be optimized. */
    drflac_uint64 totalSamplesRead = 0;

    while (samplesToRead > 0)
    {
        drflac_uint64 i;
        drflac_int32 samples32[4096];
        drflac_uint64 samplesJustRead = drflac_read_s32(pFlac, (samplesToRead > 4096) ? 4096 : samplesToRead, samples32);
        if (samplesJustRead == 0)
            break;  /* Reached the end. */

        /* s32 -> f32 */
        for (i = 0; i < samplesJustRead; ++i)
            pBufferOut[i] = (float)(samples32[i] / 2147483648.0);

        totalSamplesRead += samplesJustRead;
        samplesToRead -= samplesJustRead;
        pBufferOut += samplesJustRead;
    }

    return totalSamplesRead;
}

drflac_bool32 drflac_seek_to_sample(drflac* pFlac, drflac_uint64 sampleIndex)
{
    if (pFlac == NULL)
        return DRFLAC_FALSE;

    /* If we don't know where the first frame begins then we can't seek. This will happen when the STREAMINFO block was not present
     * when the decoder was opened. */
    if (pFlac->firstFramePos == 0)
        return DRFLAC_FALSE;

    if (sampleIndex == 0)
        return drflac__seek_to_first_frame(pFlac);

    /* Clamp the sample to the end. */
    if (sampleIndex >= pFlac->totalSampleCount)
        sampleIndex  = pFlac->totalSampleCount - 1;


    /* Different techniques depending on encapsulation. Using the native FLAC seektable with Ogg encapsulation is a bit awkward so
     * we'll instead use Ogg's natural seeking facility. */
#ifndef DR_FLAC_NO_OGG
    if (pFlac->container == drflac_container_ogg)
       return drflac_ogg__seek_to_sample(pFlac, sampleIndex);
    else
#endif
    {
        /* First try seeking via the seek table. If this fails, fall back to a brute force seek which is much slower. */
        if (!drflac__seek_to_sample__seek_table(pFlac, sampleIndex))
            return drflac__seek_to_sample__brute_force(pFlac, sampleIndex);
    }


    return DRFLAC_TRUE;
}



/* High Level APIs */

/* I couldn't figure out where SIZE_MAX was defined for VC6. If anybody knows, let me know. */
#if defined(_MSC_VER) && _MSC_VER <= 1200
#ifdef DRFLAC_64BIT
#define SIZE_MAX    ((drflac_uint64)0xFFFFFFFFFFFFFFFF)
#else
#define SIZE_MAX    0xFFFFFFFF
#endif
#endif

/* Using a macro as the definition of the drflac__full_decode_and_close_*() API family. Sue me. */
#define DRFLAC_DEFINE_FULL_DECODE_AND_CLOSE(extension, type) \
static type* drflac__full_decode_and_close_ ## extension (drflac* pFlac, unsigned int* channelsOut, unsigned int* sampleRateOut, drflac_uint64* totalSampleCountOut)\
{ \
    drflac_uint64 totalSampleCount; \
    type* pSampleData = NULL; \
    drflac_assert(pFlac != NULL); \
    totalSampleCount = pFlac->totalSampleCount; \
    if (totalSampleCount == 0) { \
        type buffer[4096]; \
        drflac_uint64 samplesRead; \
        size_t sampleDataBufferSize = sizeof(buffer); \
        pSampleData = (type*)DRFLAC_MALLOC(sampleDataBufferSize); \
        if (pSampleData == NULL) \
            goto on_error; \
        while ((samplesRead = (drflac_uint64)drflac_read_##extension(pFlac, sizeof(buffer)/sizeof(buffer[0]), buffer)) > 0) {                                       \
            if (((totalSampleCount + samplesRead) * sizeof(type)) > sampleDataBufferSize) {                                                                         \
               type *pNewSampleData; \
                sampleDataBufferSize *= 2;                                                                                                                          \
                pNewSampleData = (type*)DRFLAC_REALLOC(pSampleData, sampleDataBufferSize);                                                                    \
                if (pNewSampleData == NULL) {                                                                                                                       \
                    DRFLAC_FREE(pSampleData);                                                                                                                       \
                    goto on_error;                                                                                                                                  \
                }                                                                                                                                                   \
                                                                                                                                                                    \
                pSampleData = pNewSampleData;                                                                                                                       \
            }                                                                                                                                                       \
                                                                                                                                                                    \
            drflac_copy_memory(pSampleData + totalSampleCount, buffer, (size_t)(samplesRead*sizeof(type)));                                                         \
            totalSampleCount += samplesRead;                                                                                                                        \
        }                                                                                                                                                           \
                                                                                                                                                                    \
        /* At this point everything should be decoded, but we just want to fill the unused part buffer with silence - need to                                       \
           protect those ears from random noise! */                                                                                                                 \
        drflac_zero_memory(pSampleData + totalSampleCount, (size_t)(sampleDataBufferSize - totalSampleCount*sizeof(type)));                                         \
    } else {                                                                                                                                                        \
        drflac_uint64 dataSize = totalSampleCount * sizeof(type);                                                                                                   \
        if (dataSize > SIZE_MAX) {                                                                                                                                  \
            goto on_error;  /* The decoded data is too big. */                                                                                                      \
        }                                                                                                                                                           \
                                                                                                                                                                    \
        pSampleData = (type*)DRFLAC_MALLOC((size_t)dataSize);    /* <-- Safe cast as per the check above. */                                                        \
        if (pSampleData == NULL) {                                                                                                                                  \
            goto on_error;                                                                                                                                          \
        }                                                                                                                                                           \
                                                                                                                                                                    \
        totalSampleCount = drflac_read_##extension(pFlac, pFlac->totalSampleCount, pSampleData);                                                                    \
    }                                                                                                                                                               \
                                                                                                                                                                    \
    if (sampleRateOut) *sampleRateOut = pFlac->sampleRate;                                                                                                          \
    if (channelsOut) *channelsOut = pFlac->channels;                                                                                                                \
    if (totalSampleCountOut) *totalSampleCountOut = totalSampleCount;                                                                                               \
                                                                                                                                                                    \
    drflac_close(pFlac);                                                                                                                                            \
    return pSampleData;                                                                                                                                             \
                                                                                                                                                                    \
on_error:                                                                                                                                                           \
    drflac_close(pFlac);                                                                                                                                            \
    return NULL;                                                                                                                                                    \
}

DRFLAC_DEFINE_FULL_DECODE_AND_CLOSE(s32, drflac_int32)
DRFLAC_DEFINE_FULL_DECODE_AND_CLOSE(s16, drflac_int16)
DRFLAC_DEFINE_FULL_DECODE_AND_CLOSE(f32, float)

drflac_int32* drflac_open_and_decode_s32(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   /* Safety. */
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open(onRead, onSeek, pUserData);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_s32(pFlac, channels, sampleRate, totalSampleCount);
}

drflac_int16* drflac_open_and_decode_s16(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   /* Safety. */
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open(onRead, onSeek, pUserData);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_s16(pFlac, channels, sampleRate, totalSampleCount);
}

float* drflac_open_and_decode_f32(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   /* Safety. */
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open(onRead, onSeek, pUserData);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_f32(pFlac, channels, sampleRate, totalSampleCount);
}

#ifndef DR_FLAC_NO_STDIO
drflac_int32* drflac_open_and_decode_file_s32(const char* filename, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open_file(filename);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_s32(pFlac, channels, sampleRate, totalSampleCount);
}

drflac_int16* drflac_open_and_decode_file_s16(const char* filename, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open_file(filename);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_s16(pFlac, channels, sampleRate, totalSampleCount);
}

float* drflac_open_and_decode_file_f32(const char* filename, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open_file(filename);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_f32(pFlac, channels, sampleRate, totalSampleCount);
}
#endif

drflac_int32* drflac_open_and_decode_memory_s32(const void* data, size_t dataSize, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac *pFlac;

   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open_memory(data, dataSize);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_s32(pFlac, channels, sampleRate, totalSampleCount);
}

drflac_int16* drflac_open_and_decode_memory_s16(const void* data, size_t dataSize, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open_memory(data, dataSize);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_s16(pFlac, channels, sampleRate, totalSampleCount);
}

float* drflac_open_and_decode_memory_f32(const void* data, size_t dataSize, unsigned int* channels, unsigned int* sampleRate, drflac_uint64* totalSampleCount)
{
   drflac* pFlac;
   if (sampleRate) *sampleRate = 0;
   if (channels) *channels = 0;
   if (totalSampleCount) *totalSampleCount = 0;

   pFlac = drflac_open_memory(data, dataSize);
   if (pFlac == NULL)
      return NULL;

   return drflac__full_decode_and_close_f32(pFlac, channels, sampleRate, totalSampleCount);
}

void drflac_free(void* pSampleDataReturnedByOpenAndDecode)
{
    DRFLAC_FREE(pSampleDataReturnedByOpenAndDecode);
}




void drflac_init_vorbis_comment_iterator(drflac_vorbis_comment_iterator* pIter, drflac_uint32 commentCount, const char* pComments)
{
    if (pIter == NULL)
        return;

    pIter->countRemaining = commentCount;
    pIter->pRunningData   = pComments;
}

const char* drflac_next_vorbis_comment(drflac_vorbis_comment_iterator* pIter, drflac_uint32* pCommentLengthOut)
{
   const char* pComment;
   drflac_uint32 length;
    /* Safety. */
    if (pCommentLengthOut) *pCommentLengthOut = 0;

    if (pIter == NULL || pIter->countRemaining == 0 || pIter->pRunningData == NULL)
        return NULL;

    length                 = drflac__le2host_32(*(drflac_uint32*)pIter->pRunningData);
    pIter->pRunningData   += 4;

    pComment               = pIter->pRunningData;
    pIter->pRunningData   += length;
    pIter->countRemaining -= 1;

    if (pCommentLengthOut) *pCommentLengthOut = length;
    return pComment;
}
#endif  /* DR_FLAC_IMPLEMENTATION */

/*
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to <http://unlicense.org/>
*/