gecko-dev/content/media/MediaDecoderReader.h

552 lines
17 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#if !defined(MediaDecoderReader_h_)
#define MediaDecoderReader_h_
#include <nsDeque.h>
#include "nsSize.h"
#include "mozilla/ReentrantMonitor.h"
#include "MediaStreamGraph.h"
#include "SharedBuffer.h"
#include "ImageLayers.h"
#include "AudioSampleFormat.h"
#include "MediaResource.h"
#include "mozilla/dom/HTMLMediaElement.h"
namespace mozilla {
class AbstractMediaDecoder;
// Stores info relevant to presenting media frames.
class VideoInfo {
public:
VideoInfo()
: mAudioRate(44100),
mAudioChannels(2),
mDisplay(0,0),
mStereoMode(STEREO_MODE_MONO),
mHasAudio(false),
mHasVideo(false)
{}
// Returns true if it's safe to use aPicture as the picture to be
// extracted inside a frame of size aFrame, and scaled up to and displayed
// at a size of aDisplay. You should validate the frame, picture, and
// display regions before using them to display video frames.
static bool ValidateVideoRegion(const nsIntSize& aFrame,
const nsIntRect& aPicture,
const nsIntSize& aDisplay);
// Sample rate.
uint32_t mAudioRate;
// Number of audio channels.
uint32_t mAudioChannels;
// Size in pixels at which the video is rendered. This is after it has
// been scaled by its aspect ratio.
nsIntSize mDisplay;
// Indicates the frame layout for single track stereo videos.
StereoMode mStereoMode;
// True if we have an active audio bitstream.
bool mHasAudio;
// True if we have an active video bitstream.
bool mHasVideo;
};
// Holds chunk a decoded audio frames.
class AudioData {
public:
AudioData(int64_t aOffset,
int64_t aTime,
int64_t aDuration,
uint32_t aFrames,
AudioDataValue* aData,
uint32_t aChannels)
: mOffset(aOffset),
mTime(aTime),
mDuration(aDuration),
mFrames(aFrames),
mChannels(aChannels),
mAudioData(aData)
{
MOZ_COUNT_CTOR(AudioData);
}
~AudioData()
{
MOZ_COUNT_DTOR(AudioData);
}
// If mAudioBuffer is null, creates it from mAudioData.
void EnsureAudioBuffer();
int64_t GetEnd() { return mTime + mDuration; }
// Approximate byte offset of the end of the page on which this chunk
// ends.
const int64_t mOffset;
int64_t mTime; // Start time of data in usecs.
const int64_t mDuration; // In usecs.
const uint32_t mFrames;
const uint32_t mChannels;
// At least one of mAudioBuffer/mAudioData must be non-null.
// mChannels channels, each with mFrames frames
nsRefPtr<SharedBuffer> mAudioBuffer;
// mFrames frames, each with mChannels values
nsAutoArrayPtr<AudioDataValue> mAudioData;
};
namespace layers {
class GraphicBufferLocked;
}
// Holds a decoded video frame, in YCbCr format. These are queued in the reader.
class VideoData {
public:
typedef layers::ImageContainer ImageContainer;
typedef layers::Image Image;
// YCbCr data obtained from decoding the video. The index's are:
// 0 = Y
// 1 = Cb
// 2 = Cr
struct YCbCrBuffer {
struct Plane {
uint8_t* mData;
uint32_t mWidth;
uint32_t mHeight;
uint32_t mStride;
uint32_t mOffset;
uint32_t mSkip;
};
Plane mPlanes[3];
};
// Constructs a VideoData object. If aImage is NULL, creates a new Image
// holding a copy of the YCbCr data passed in aBuffer. If aImage is not NULL,
// it's stored as the underlying video image and aBuffer is assumed to point
// to memory within aImage so no copy is made. aTimecode is a codec specific
// number representing the timestamp of the frame of video data. Returns
// nsnull if an error occurs. This may indicate that memory couldn't be
// allocated to create the VideoData object, or it may indicate some problem
// with the input data (e.g. negative stride).
static VideoData* Create(VideoInfo& aInfo,
ImageContainer* aContainer,
Image* aImage,
int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
const YCbCrBuffer &aBuffer,
bool aKeyframe,
int64_t aTimecode,
nsIntRect aPicture);
// Variant that always makes a copy of aBuffer
static VideoData* Create(VideoInfo& aInfo,
ImageContainer* aContainer,
int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
const YCbCrBuffer &aBuffer,
bool aKeyframe,
int64_t aTimecode,
nsIntRect aPicture);
// Variant to create a VideoData instance given an existing aImage
static VideoData* Create(VideoInfo& aInfo,
Image* aImage,
int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
const YCbCrBuffer &aBuffer,
bool aKeyframe,
int64_t aTimecode,
nsIntRect aPicture);
static VideoData* Create(VideoInfo& aInfo,
ImageContainer* aContainer,
int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
layers::GraphicBufferLocked* aBuffer,
bool aKeyframe,
int64_t aTimecode,
nsIntRect aPicture);
static VideoData* CreateFromImage(VideoInfo& aInfo,
ImageContainer* aContainer,
int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
const nsRefPtr<Image>& aImage,
bool aKeyframe,
int64_t aTimecode,
nsIntRect aPicture);
// Constructs a duplicate VideoData object. This intrinsically tells the
// player that it does not need to update the displayed frame when this
// frame is played; this frame is identical to the previous.
static VideoData* CreateDuplicate(int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
int64_t aTimecode)
{
return new VideoData(aOffset, aTime, aEndTime, aTimecode);
}
~VideoData();
int64_t GetEnd() { return mEndTime; }
// Dimensions at which to display the video frame. The picture region
// will be scaled to this size. This is should be the picture region's
// dimensions scaled with respect to its aspect ratio.
nsIntSize mDisplay;
// Approximate byte offset of the end of the frame in the media.
int64_t mOffset;
// Start time of frame in microseconds.
int64_t mTime;
// End time of frame in microseconds.
int64_t mEndTime;
// Codec specific internal time code. For Ogg based codecs this is the
// granulepos.
int64_t mTimecode;
// This frame's image.
nsRefPtr<Image> mImage;
// When true, denotes that this frame is identical to the frame that
// came before; it's a duplicate. mBuffer will be empty.
bool mDuplicate;
bool mKeyframe;
public:
VideoData(int64_t aOffset, int64_t aTime, int64_t aEndTime, int64_t aTimecode);
VideoData(int64_t aOffset,
int64_t aTime,
int64_t aEndTime,
bool aKeyframe,
int64_t aTimecode,
nsIntSize aDisplay);
};
// Thread and type safe wrapper around nsDeque.
template <class T>
class MediaQueueDeallocator : public nsDequeFunctor {
virtual void* operator() (void* anObject) {
delete static_cast<T*>(anObject);
return nullptr;
}
};
template <class T> class MediaQueue : private nsDeque {
public:
MediaQueue()
: nsDeque(new MediaQueueDeallocator<T>()),
mReentrantMonitor("mediaqueue"),
mEndOfStream(false)
{}
~MediaQueue() {
Reset();
}
inline int32_t GetSize() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return nsDeque::GetSize();
}
inline void Push(T* aItem) {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
nsDeque::Push(aItem);
}
inline void PushFront(T* aItem) {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
nsDeque::PushFront(aItem);
}
inline T* Pop() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return static_cast<T*>(nsDeque::Pop());
}
inline T* PopFront() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return static_cast<T*>(nsDeque::PopFront());
}
inline T* Peek() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return static_cast<T*>(nsDeque::Peek());
}
inline T* PeekFront() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return static_cast<T*>(nsDeque::PeekFront());
}
inline void Empty() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
nsDeque::Empty();
}
inline void Erase() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
nsDeque::Erase();
}
void Reset() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
while (GetSize() > 0) {
T* x = PopFront();
delete x;
}
mEndOfStream = false;
}
bool AtEndOfStream() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return GetSize() == 0 && mEndOfStream;
}
// Returns true if the media queue has had its last item added to it.
// This happens when the media stream has been completely decoded. Note this
// does not mean that the corresponding stream has finished playback.
bool IsFinished() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
return mEndOfStream;
}
// Informs the media queue that it won't be receiving any more items.
void Finish() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
mEndOfStream = true;
}
// Returns the approximate number of microseconds of items in the queue.
int64_t Duration() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
if (GetSize() < 2) {
return 0;
}
T* last = Peek();
T* first = PeekFront();
return last->mTime - first->mTime;
}
void LockedForEach(nsDequeFunctor& aFunctor) const {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
ForEach(aFunctor);
}
// Extracts elements from the queue into aResult, in order.
// Elements whose start time is before aTime are ignored.
void GetElementsAfter(int64_t aTime, nsTArray<T*>* aResult) {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
if (!GetSize())
return;
int32_t i;
for (i = GetSize() - 1; i > 0; --i) {
T* v = static_cast<T*>(ObjectAt(i));
if (v->GetEnd() < aTime)
break;
}
// Elements less than i have a end time before aTime. It's also possible
// that the element at i has a end time before aTime, but that's OK.
for (; i < GetSize(); ++i) {
aResult->AppendElement(static_cast<T*>(ObjectAt(i)));
}
}
uint32_t FrameCount() {
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
uint32_t frames = 0;
for (int32_t i = 0; i < GetSize(); ++i) {
T* v = static_cast<T*>(ObjectAt(i));
frames += v->mFrames;
}
return frames;
}
private:
mutable ReentrantMonitor mReentrantMonitor;
// True when we've decoded the last frame of data in the
// bitstream for which we're queueing frame data.
bool mEndOfStream;
};
// Encapsulates the decoding and reading of media data. Reading can only be
// done on the decode thread. Never hold the decoder monitor when
// calling into this class. Unless otherwise specified, methods and fields of
// this class can only be accessed on the decode thread.
class MediaDecoderReader {
public:
MediaDecoderReader(AbstractMediaDecoder* aDecoder);
virtual ~MediaDecoderReader();
// Initializes the reader, returns NS_OK on success, or NS_ERROR_FAILURE
// on failure.
virtual nsresult Init(MediaDecoderReader* aCloneDonor) = 0;
// True if this reader is waiting media resource allocation
virtual bool IsWaitingMediaResources() { return false; }
// True when this reader need to become dormant state
virtual bool IsDormantNeeded() { return false; }
// Release media resources they should be released in dormant state
virtual void ReleaseMediaResources() {};
// Resets all state related to decoding, emptying all buffers etc.
virtual nsresult ResetDecode();
// Decodes an unspecified amount of audio data, enqueuing the audio data
// in mAudioQueue. Returns true when there's more audio to decode,
// false if the audio is finished, end of file has been reached,
// or an un-recoverable read error has occured.
virtual bool DecodeAudioData() = 0;
#ifdef MOZ_DASH
// Steps to carry out at the start of the |DecodeLoop|.
virtual void PrepareToDecode() { }
#endif
// Reads and decodes one video frame. Packets with a timestamp less
// than aTimeThreshold will be decoded (unless they're not keyframes
// and aKeyframeSkip is true), but will not be added to the queue.
virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
int64_t aTimeThreshold) = 0;
virtual bool HasAudio() = 0;
virtual bool HasVideo() = 0;
// Read header data for all bitstreams in the file. Fills aInfo with
// the data required to present the media, and optionally fills *aTags
// with tag metadata from the file.
// Returns NS_OK on success, or NS_ERROR_FAILURE on failure.
virtual nsresult ReadMetadata(VideoInfo* aInfo,
MetadataTags** aTags) = 0;
// Stores the presentation time of the first frame we'd be able to play if
// we started playback at the current position. Returns the first video
// frame, if we have video.
virtual VideoData* FindStartTime(int64_t& aOutStartTime);
// Moves the decode head to aTime microseconds. aStartTime and aEndTime
// denote the start and end times of the media in usecs, and aCurrentTime
// is the current playback position in microseconds.
virtual nsresult Seek(int64_t aTime,
int64_t aStartTime,
int64_t aEndTime,
int64_t aCurrentTime) = 0;
// Called when the decode thread is started, before calling any other
// decode, read metadata, or seek functions. Do any thread local setup
// in this function.
virtual void OnDecodeThreadStart() {}
// Called when the decode thread is about to finish, after all calls to
// any other decode, read metadata, or seek functions. Any backend specific
// thread local tear down must be done in this function. Note that another
// decode thread could start up and run in future.
virtual void OnDecodeThreadFinish() {}
protected:
// Queue of audio frames. This queue is threadsafe, and is accessed from
// the audio, decoder, state machine, and main threads.
MediaQueue<AudioData> mAudioQueue;
// Queue of video frames. This queue is threadsafe, and is accessed from
// the decoder, state machine, and main threads.
MediaQueue<VideoData> mVideoQueue;
public:
// Populates aBuffered with the time ranges which are buffered. aStartTime
// must be the presentation time of the first frame in the media, e.g.
// the media time corresponding to playback time/position 0. This function
// should only be called on the main thread.
virtual nsresult GetBuffered(dom::TimeRanges* aBuffered,
int64_t aStartTime) = 0;
class VideoQueueMemoryFunctor : public nsDequeFunctor {
public:
VideoQueueMemoryFunctor() : mResult(0) {}
virtual void* operator()(void* anObject);
int64_t mResult;
};
virtual int64_t VideoQueueMemoryInUse() {
VideoQueueMemoryFunctor functor;
mVideoQueue.LockedForEach(functor);
return functor.mResult;
}
class AudioQueueMemoryFunctor : public nsDequeFunctor {
public:
AudioQueueMemoryFunctor() : mResult(0) {}
virtual void* operator()(void* anObject) {
const AudioData* audioData = static_cast<const AudioData*>(anObject);
mResult += audioData->mFrames * audioData->mChannels * sizeof(AudioDataValue);
return nullptr;
}
int64_t mResult;
};
virtual int64_t AudioQueueMemoryInUse() {
AudioQueueMemoryFunctor functor;
mAudioQueue.LockedForEach(functor);
return functor.mResult;
}
// Only used by WebMReader for now, so stub here rather than in every
// reader than inherits from MediaDecoderReader.
virtual void NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset) {}
virtual MediaQueue<AudioData>& AudioQueue() { return mAudioQueue; }
virtual MediaQueue<VideoData>& VideoQueue() { return mVideoQueue; }
// Returns a pointer to the decoder.
AbstractMediaDecoder* GetDecoder() {
return mDecoder;
}
AudioData* DecodeToFirstAudioData();
VideoData* DecodeToFirstVideoData();
protected:
// Pumps the decode until we reach frames required to play at time aTarget
// (usecs).
nsresult DecodeToTarget(int64_t aTarget);
// Reference to the owning decoder object.
AbstractMediaDecoder* mDecoder;
// Stores presentation info required for playback.
VideoInfo mInfo;
};
} // namespace mozilla
#endif