third_party_ffmpeg/libavutil/frame.h
Anton Khirnov 0232ba62a2 frame: clarify buf documentation
Mention explicitly that the array must be filled contiguously.
2015-02-08 21:28:31 +01:00

618 lines
17 KiB
C

/*
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @ingroup lavu_frame
* reference-counted frame API
*/
#ifndef AVUTIL_FRAME_H
#define AVUTIL_FRAME_H
#include <stdint.h>
#include "avutil.h"
#include "buffer.h"
#include "dict.h"
#include "rational.h"
#include "samplefmt.h"
#include "pixfmt.h"
#include "version.h"
/**
* @defgroup lavu_frame AVFrame
* @ingroup lavu_data
*
* @{
* AVFrame is an abstraction for reference-counted raw multimedia data.
*/
enum AVFrameSideDataType {
/**
* The data is the AVPanScan struct defined in libavcodec.
*/
AV_FRAME_DATA_PANSCAN,
/**
* ATSC A53 Part 4 Closed Captions.
* A53 CC bitstream is stored as uint8_t in AVFrameSideData.data.
* The number of bytes of CC data is AVFrameSideData.size.
*/
AV_FRAME_DATA_A53_CC,
/**
* Stereoscopic 3d metadata.
* The data is the AVStereo3D struct defined in libavutil/stereo3d.h.
*/
AV_FRAME_DATA_STEREO3D,
/**
* The data is the AVMatrixEncoding enum defined in libavutil/channel_layout.h.
*/
AV_FRAME_DATA_MATRIXENCODING,
/**
* Metadata relevant to a downmix procedure.
* The data is the AVDownmixInfo struct defined in libavutil/downmix_info.h.
*/
AV_FRAME_DATA_DOWNMIX_INFO,
/**
* ReplayGain information in the form of the AVReplayGain struct.
*/
AV_FRAME_DATA_REPLAYGAIN,
/**
* This side data contains a 3x3 transformation matrix describing an affine
* transformation that needs to be applied to the frame for correct
* presentation.
*
* See libavutil/display.h for a detailed description of the data.
*/
AV_FRAME_DATA_DISPLAYMATRIX,
/**
* Active Format Description data consisting of a single byte as specified
* in ETSI TS 101 154 using enum AVActiveFormatDescription.
*/
AV_FRAME_DATA_AFD,
/**
* This side data must be associated with an audio frame and corresponds to
* enum AVAudioServiceType defined in avcodec.h.
*/
AV_FRAME_DATA_AUDIO_SERVICE_TYPE,
};
enum AVActiveFormatDescription {
AV_AFD_SAME = 8,
AV_AFD_4_3 = 9,
AV_AFD_16_9 = 10,
AV_AFD_14_9 = 11,
AV_AFD_4_3_SP_14_9 = 13,
AV_AFD_16_9_SP_14_9 = 14,
AV_AFD_SP_4_3 = 15,
};
typedef struct AVFrameSideData {
enum AVFrameSideDataType type;
uint8_t *data;
int size;
AVDictionary *metadata;
} AVFrameSideData;
/**
* This structure describes decoded (raw) audio or video data.
*
* AVFrame must be allocated using av_frame_alloc(). Note that this only
* allocates the AVFrame itself, the buffers for the data must be managed
* through other means (see below).
* AVFrame must be freed with av_frame_free().
*
* AVFrame is typically allocated once and then reused multiple times to hold
* different data (e.g. a single AVFrame to hold frames received from a
* decoder). In such a case, av_frame_unref() will free any references held by
* the frame and reset it to its original clean state before it
* is reused again.
*
* The data described by an AVFrame is usually reference counted through the
* AVBuffer API. The underlying buffer references are stored in AVFrame.buf /
* AVFrame.extended_buf. An AVFrame is considered to be reference counted if at
* least one reference is set, i.e. if AVFrame.buf[0] != NULL. In such a case,
* every single data plane must be contained in one of the buffers in
* AVFrame.buf or AVFrame.extended_buf.
* There may be a single buffer for all the data, or one separate buffer for
* each plane, or anything in between.
*
* sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
* to the end with a minor bump.
*/
typedef struct AVFrame {
#define AV_NUM_DATA_POINTERS 8
/**
* pointer to the picture/channel planes.
* This might be different from the first allocated byte
*/
uint8_t *data[AV_NUM_DATA_POINTERS];
/**
* For video, size in bytes of each picture line.
* For audio, size in bytes of each plane.
*
* For audio, only linesize[0] may be set. For planar audio, each channel
* plane must be the same size.
*
* @note The linesize may be larger than the size of usable data -- there
* may be extra padding present for performance reasons.
*/
int linesize[AV_NUM_DATA_POINTERS];
/**
* pointers to the data planes/channels.
*
* For video, this should simply point to data[].
*
* For planar audio, each channel has a separate data pointer, and
* linesize[0] contains the size of each channel buffer.
* For packed audio, there is just one data pointer, and linesize[0]
* contains the total size of the buffer for all channels.
*
* Note: Both data and extended_data should always be set in a valid frame,
* but for planar audio with more channels that can fit in data,
* extended_data must be used in order to access all channels.
*/
uint8_t **extended_data;
/**
* width and height of the video frame
*/
int width, height;
/**
* number of audio samples (per channel) described by this frame
*/
int nb_samples;
/**
* format of the frame, -1 if unknown or unset
* Values correspond to enum AVPixelFormat for video frames,
* enum AVSampleFormat for audio)
*/
int format;
/**
* 1 -> keyframe, 0-> not
*/
int key_frame;
/**
* Picture type of the frame.
*/
enum AVPictureType pict_type;
#if FF_API_AVFRAME_LAVC
attribute_deprecated
uint8_t *base[AV_NUM_DATA_POINTERS];
#endif
/**
* Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
*/
AVRational sample_aspect_ratio;
/**
* Presentation timestamp in time_base units (time when frame should be shown to user).
*/
int64_t pts;
/**
* PTS copied from the AVPacket that was decoded to produce this frame.
*/
int64_t pkt_pts;
/**
* DTS copied from the AVPacket that triggered returning this frame.
*/
int64_t pkt_dts;
/**
* picture number in bitstream order
*/
int coded_picture_number;
/**
* picture number in display order
*/
int display_picture_number;
/**
* quality (between 1 (good) and FF_LAMBDA_MAX (bad))
*/
int quality;
#if FF_API_AVFRAME_LAVC
attribute_deprecated
int reference;
/**
* QP table
*/
attribute_deprecated
int8_t *qscale_table;
/**
* QP store stride
*/
attribute_deprecated
int qstride;
attribute_deprecated
int qscale_type;
/**
* mbskip_table[mb]>=1 if MB didn't change
* stride= mb_width = (width+15)>>4
*/
attribute_deprecated
uint8_t *mbskip_table;
/**
* motion vector table
* @code
* example:
* int mv_sample_log2= 4 - motion_subsample_log2;
* int mb_width= (width+15)>>4;
* int mv_stride= (mb_width << mv_sample_log2) + 1;
* motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
* @endcode
*/
attribute_deprecated
int16_t (*motion_val[2])[2];
/**
* macroblock type table
* mb_type_base + mb_width + 2
*/
attribute_deprecated
uint32_t *mb_type;
/**
* DCT coefficients
*/
attribute_deprecated
short *dct_coeff;
/**
* motion reference frame index
* the order in which these are stored can depend on the codec.
*/
attribute_deprecated
int8_t *ref_index[2];
#endif
/**
* for some private data of the user
*/
void *opaque;
/**
* error
*/
uint64_t error[AV_NUM_DATA_POINTERS];
#if FF_API_AVFRAME_LAVC
attribute_deprecated
int type;
#endif
/**
* When decoding, this signals how much the picture must be delayed.
* extra_delay = repeat_pict / (2*fps)
*/
int repeat_pict;
/**
* The content of the picture is interlaced.
*/
int interlaced_frame;
/**
* If the content is interlaced, is top field displayed first.
*/
int top_field_first;
/**
* Tell user application that palette has changed from previous frame.
*/
int palette_has_changed;
#if FF_API_AVFRAME_LAVC
attribute_deprecated
int buffer_hints;
/**
* Pan scan.
*/
attribute_deprecated
struct AVPanScan *pan_scan;
#endif
/**
* reordered opaque 64bit (generally an integer or a double precision float
* PTS but can be anything).
* The user sets AVCodecContext.reordered_opaque to represent the input at
* that time,
* the decoder reorders values as needed and sets AVFrame.reordered_opaque
* to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
* @deprecated in favor of pkt_pts
*/
int64_t reordered_opaque;
#if FF_API_AVFRAME_LAVC
/**
* @deprecated this field is unused
*/
attribute_deprecated void *hwaccel_picture_private;
attribute_deprecated
struct AVCodecContext *owner;
attribute_deprecated
void *thread_opaque;
/**
* log2 of the size of the block which a single vector in motion_val represents:
* (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
*/
attribute_deprecated
uint8_t motion_subsample_log2;
#endif
/**
* Sample rate of the audio data.
*/
int sample_rate;
/**
* Channel layout of the audio data.
*/
uint64_t channel_layout;
/**
* AVBuffer references backing the data for this frame. If all elements of
* this array are NULL, then this frame is not reference counted. This array
* must be filled contiguously -- if buf[i] is non-NULL then buf[j] must
* also be non-NULL for all j < i.
*
* There may be at most one AVBuffer per data plane, so for video this array
* always contains all the references. For planar audio with more than
* AV_NUM_DATA_POINTERS channels, there may be more buffers than can fit in
* this array. Then the extra AVBufferRef pointers are stored in the
* extended_buf array.
*/
AVBufferRef *buf[AV_NUM_DATA_POINTERS];
/**
* For planar audio which requires more than AV_NUM_DATA_POINTERS
* AVBufferRef pointers, this array will hold all the references which
* cannot fit into AVFrame.buf.
*
* Note that this is different from AVFrame.extended_data, which always
* contains all the pointers. This array only contains the extra pointers,
* which cannot fit into AVFrame.buf.
*
* This array is always allocated using av_malloc() by whoever constructs
* the frame. It is freed in av_frame_unref().
*/
AVBufferRef **extended_buf;
/**
* Number of elements in extended_buf.
*/
int nb_extended_buf;
AVFrameSideData **side_data;
int nb_side_data;
/**
* @defgroup lavu_frame_flags AV_FRAME_FLAGS
* Flags describing additional frame properties.
*
* @{
*/
/**
* The frame data may be corrupted, e.g. due to decoding errors.
*/
#define AV_FRAME_FLAG_CORRUPT (1 << 0)
/**
* @}
*/
/**
* Frame flags, a combination of @ref lavu_frame_flags
*/
int flags;
enum AVColorRange color_range;
enum AVColorPrimaries color_primaries;
enum AVColorTransferCharacteristic color_trc;
enum AVColorSpace colorspace;
enum AVChromaLocation chroma_location;
} AVFrame;
/**
* Allocate an AVFrame and set its fields to default values. The resulting
* struct must be freed using av_frame_free().
*
* @return An AVFrame filled with default values or NULL on failure.
*
* @note this only allocates the AVFrame itself, not the data buffers. Those
* must be allocated through other means, e.g. with av_frame_get_buffer() or
* manually.
*/
AVFrame *av_frame_alloc(void);
/**
* Free the frame and any dynamically allocated objects in it,
* e.g. extended_data. If the frame is reference counted, it will be
* unreferenced first.
*
* @param frame frame to be freed. The pointer will be set to NULL.
*/
void av_frame_free(AVFrame **frame);
/**
* Set up a new reference to the data described by the source frame.
*
* Copy frame properties from src to dst and create a new reference for each
* AVBufferRef from src.
*
* If src is not reference counted, new buffers are allocated and the data is
* copied.
*
* @return 0 on success, a negative AVERROR on error
*/
int av_frame_ref(AVFrame *dst, const AVFrame *src);
/**
* Create a new frame that references the same data as src.
*
* This is a shortcut for av_frame_alloc()+av_frame_ref().
*
* @return newly created AVFrame on success, NULL on error.
*/
AVFrame *av_frame_clone(const AVFrame *src);
/**
* Unreference all the buffers referenced by frame and reset the frame fields.
*/
void av_frame_unref(AVFrame *frame);
/**
* Move everythnig contained in src to dst and reset src.
*/
void av_frame_move_ref(AVFrame *dst, AVFrame *src);
/**
* Allocate new buffer(s) for audio or video data.
*
* The following fields must be set on frame before calling this function:
* - format (pixel format for video, sample format for audio)
* - width and height for video
* - nb_samples and channel_layout for audio
*
* This function will fill AVFrame.data and AVFrame.buf arrays and, if
* necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
* For planar formats, one buffer will be allocated for each plane.
*
* @param frame frame in which to store the new buffers.
* @param align required buffer size alignment
*
* @return 0 on success, a negative AVERROR on error.
*/
int av_frame_get_buffer(AVFrame *frame, int align);
/**
* Check if the frame data is writable.
*
* @return A positive value if the frame data is writable (which is true if and
* only if each of the underlying buffers has only one reference, namely the one
* stored in this frame). Return 0 otherwise.
*
* If 1 is returned the answer is valid until av_buffer_ref() is called on any
* of the underlying AVBufferRefs (e.g. through av_frame_ref() or directly).
*
* @see av_frame_make_writable(), av_buffer_is_writable()
*/
int av_frame_is_writable(AVFrame *frame);
/**
* Ensure that the frame data is writable, avoiding data copy if possible.
*
* Do nothing if the frame is writable, allocate new buffers and copy the data
* if it is not.
*
* @return 0 on success, a negative AVERROR on error.
*
* @see av_frame_is_writable(), av_buffer_is_writable(),
* av_buffer_make_writable()
*/
int av_frame_make_writable(AVFrame *frame);
/**
* Copy the frame data from src to dst.
*
* This function does not allocate anything, dst must be already initialized and
* allocated with the same parameters as src.
*
* This function only copies the frame data (i.e. the contents of the data /
* extended data arrays), not any other properties.
*
* @return >= 0 on success, a negative AVERROR on error.
*/
int av_frame_copy(AVFrame *dst, const AVFrame *src);
/**
* Copy only "metadata" fields from src to dst.
*
* Metadata for the purpose of this function are those fields that do not affect
* the data layout in the buffers. E.g. pts, sample rate (for audio) or sample
* aspect ratio (for video), but not width/height or channel layout.
* Side data is also copied.
*/
int av_frame_copy_props(AVFrame *dst, const AVFrame *src);
/**
* Get the buffer reference a given data plane is stored in.
*
* @param plane index of the data plane of interest in frame->extended_data.
*
* @return the buffer reference that contains the plane or NULL if the input
* frame is not valid.
*/
AVBufferRef *av_frame_get_plane_buffer(AVFrame *frame, int plane);
/**
* Add a new side data to a frame.
*
* @param frame a frame to which the side data should be added
* @param type type of the added side data
* @param size size of the side data
*
* @return newly added side data on success, NULL on error
*/
AVFrameSideData *av_frame_new_side_data(AVFrame *frame,
enum AVFrameSideDataType type,
int size);
/**
* @return a pointer to the side data of a given type on success, NULL if there
* is no side data with such type in this frame.
*/
AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
enum AVFrameSideDataType type);
/**
* If side data of the supplied type exists in the frame, free it and remove it
* from the frame.
*/
void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type);
/**
* @}
*/
#endif /* AVUTIL_FRAME_H */