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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 */
#if !defined(MediaDataDemuxer_h)
# define MediaDataDemuxer_h
# include "DecoderDoctorLogger.h"
# include "mozilla/MozPromise.h"
# include "mozilla/UniquePtr.h"
# include "MediaData.h"
# include "MediaInfo.h"
# include "MediaResult.h"
# include "TimeUnits.h"
# include "nsISupportsImpl.h"
# include "mozilla/RefPtr.h"
# include "nsTArray.h"
namespace mozilla {
class MediaTrackDemuxer;
class TrackMetadataHolder;
// Allows reading the media data: to retrieve the metadata and demux samples.
// MediaDataDemuxer isn't designed to be thread safe.
// When used by the MediaFormatDecoder, care is taken to ensure that the demuxer
// will never be called from more than one thread at once.
class MediaDataDemuxer : public DecoderDoctorLifeLogger<MediaDataDemuxer> {
typedef MozPromise<MediaResult, MediaResult, /* IsExclusive = */ true>
// Initializes the demuxer. Other methods cannot be called unless
// initialization has completed and succeeded.
// Typically a demuxer will wait to parse the metadata before resolving the
// promise. The promise must not be resolved until sufficient data is
// supplied. For example, an incomplete metadata would cause the promise to be
// rejected should no more data be coming, while the demuxer would wait
// otherwise.
virtual RefPtr<InitPromise> Init() = 0;
// Returns the number of tracks of aType type available. A value of
// 0 indicates that no such type is available.
virtual uint32_t GetNumberTracks(TrackInfo::TrackType aType) const = 0;
// Returns the MediaTrackDemuxer associated with aTrackNumber aType track.
// aTrackNumber is not to be confused with the Track ID.
// aTrackNumber must be constrained between 0 and GetNumberTracks(aType) - 1
// The actual Track ID is to be retrieved by calling
// MediaTrackDemuxer::TrackInfo.
virtual already_AddRefed<MediaTrackDemuxer> GetTrackDemuxer(
TrackInfo::TrackType aType, uint32_t aTrackNumber) = 0;
// Returns true if the underlying resource allows seeking.
virtual bool IsSeekable() const = 0;
// Returns true if the underlying resource can only seek within buffered
// ranges.
virtual bool IsSeekableOnlyInBufferedRanges() const { return false; }
// Returns the media's crypto information, or nullptr if media isn't
// encrypted.
virtual UniquePtr<EncryptionInfo> GetCrypto() { return nullptr; }
// Notifies the demuxer that the underlying resource has received more data
// since the demuxer was initialized.
// The demuxer can use this mechanism to inform all track demuxers that new
// data is available and to refresh its buffered range.
virtual void NotifyDataArrived() {}
// Notifies the demuxer that the underlying resource has had data removed
// since the demuxer was initialized.
// The demuxer can use this mechanism to inform all track demuxers to update
// its buffered range.
// This will be called should the demuxer be used with MediaSource.
virtual void NotifyDataRemoved() {}
// Indicate to MediaFormatReader if it should compute the start time
// of the demuxed data. If true (default) the first sample returned will be
// used as reference time base.
virtual bool ShouldComputeStartTime() const { return true; }
virtual ~MediaDataDemuxer() = default;
class MediaTrackDemuxer : public DecoderDoctorLifeLogger<MediaTrackDemuxer> {
class SamplesHolder {
void AppendSample(RefPtr<MediaRawData>& aSample) {
const nsTArray<RefPtr<MediaRawData>>& GetSamples() const {
return mSamples;
// This method is only used to do the move semantic for mSamples, do not
// append any element to the samples we returns. We should always append new
// sample to mSamples via `AppendSample()`.
nsTArray<RefPtr<MediaRawData>>& GetMovableSamples() { return mSamples; }
~SamplesHolder() = default;
nsTArray<RefPtr<MediaRawData>> mSamples;
class SkipFailureHolder {
SkipFailureHolder(const MediaResult& aFailure, uint32_t aSkipped)
: mFailure(aFailure), mSkipped(aSkipped) {}
MediaResult mFailure;
uint32_t mSkipped;
typedef MozPromise<media::TimeUnit, MediaResult, /* IsExclusive = */ true>
typedef MozPromise<RefPtr<SamplesHolder>, MediaResult,
/* IsExclusive = */ true>
typedef MozPromise<uint32_t, SkipFailureHolder, /* IsExclusive = */ true>
// Returns the TrackInfo (a.k.a Track Description) for this track.
// The TrackInfo returned will be:
// TrackInfo::kVideoTrack -> VideoInfo.
// TrackInfo::kAudioTrack -> AudioInfo.
// respectively.
virtual UniquePtr<TrackInfo> GetInfo() const = 0;
// Seeks to aTime. Upon success, SeekPromise will be resolved with the
// actual time seeked to. Typically the random access point time
virtual RefPtr<SeekPromise> Seek(const media::TimeUnit& aTime) = 0;
// Returns the next aNumSamples sample(s) available.
// If only a lesser amount of samples is available, only those will be
// returned.
// A aNumSamples value of -1 indicates to return all remaining samples.
// A video sample is typically made of a single video frame while an audio
// sample will contains multiple audio frames.
virtual RefPtr<SamplesPromise> GetSamples(int32_t aNumSamples = 1) = 0;
// Returns true if a call to GetSamples() may block while waiting on the
// underlying resource to return the data.
// This is used by the MediaFormatReader to determine if buffering heuristics
// should be used.
virtual bool GetSamplesMayBlock() const { return true; }
// Cancel all pending actions (Seek, GetSamples) and reset current state
// All pending promises are to be rejected with CANCEL.
// The next call to GetSamples would return the first sample available in the
// track.
virtual void Reset() = 0;
// Returns timestamp of next random access point or an error if the demuxer
// can't report this.
virtual nsresult GetNextRandomAccessPoint(media::TimeUnit* aTime) {
// Returns timestamp of previous random access point or an error if the
// demuxer can't report this.
virtual nsresult GetPreviousRandomAccessPoint(media::TimeUnit* aTime) {
// Skip frames until the next Random Access Point located after
// aTimeThreshold.
// The first frame returned by the next call to GetSamples() will be the
// first random access point found after aTimeThreshold.
// Upon success, returns the number of frames skipped.
virtual RefPtr<SkipAccessPointPromise> SkipToNextRandomAccessPoint(
const media::TimeUnit& aTimeThreshold) = 0;
// Gets the resource's offset used for the last Seek() or GetSample().
// A negative value indicates that this functionality isn't supported.
virtual int64_t GetResourceOffset() const { return -1; }
virtual TrackInfo::TrackType GetType() const { return GetInfo()->GetType(); }
virtual media::TimeIntervals GetBuffered() = 0;
// By default, it is assumed that the entire resource can be evicted once
// all samples have been demuxed.
virtual int64_t GetEvictionOffset(const media::TimeUnit& aTime) {
return INT64_MAX;
// If the MediaTrackDemuxer and MediaDataDemuxer hold cross references.
// BreakCycles must be overridden.
virtual void BreakCycles() {}
virtual ~MediaTrackDemuxer() = default;
} // namespace mozilla
#endif // MediaDataDemuxer_h