/* 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/. */

#ifndef MP3_DEMUXER_H_

#define MP3_DEMUXER_H_

#include "MediaDataDemuxer.h"

#include "MediaResource.h"

#include "MP3FrameParser.h"

namespace mozilla {

class MP3TrackDemuxer;

DDLoggedTypeDeclNameAndBase(MP3Demuxer, MediaDataDemuxer);

DDLoggedTypeNameAndBase(MP3TrackDemuxer, MediaTrackDemuxer);

class MP3Demuxer

  : public MediaDataDemuxer

  , public DecoderDoctorLifeLogger<MP3Demuxer>

{

public:

  // MediaDataDemuxer interface.

  explicit MP3Demuxer(MediaResource* aSource);

  RefPtr<InitPromise> Init() override;

  uint32_t GetNumberTracks(TrackInfo::TrackType aType) const override;

  already_AddRefed<MediaTrackDemuxer> GetTrackDemuxer(

      TrackInfo::TrackType aType, uint32_t aTrackNumber) override;

  bool IsSeekable() const override;

  void NotifyDataArrived() override;

  void NotifyDataRemoved() override;

private:

  // Synchronous initialization.

  bool InitInternal();

  RefPtr<MediaResource> mSource;

  RefPtr<MP3TrackDemuxer> mTrackDemuxer;

};

// The MP3 demuxer used to extract MPEG frames and side information out of

// MPEG streams.

class MP3TrackDemuxer

  : public MediaTrackDemuxer

  , public DecoderDoctorLifeLogger<MP3TrackDemuxer>

{

public:

  // Constructor, expecting a valid media resource.

  explicit MP3TrackDemuxer(MediaResource* aSource);

  // Initializes the track demuxer by reading the first frame for meta data.

  // Returns initialization success state.

  bool Init();

  // Returns the total stream length if known, -1 otherwise.

  int64_t StreamLength() const;

  // Returns the estimated stream duration, or a 0-duration if unknown.

  media::TimeUnit Duration() const;

  // Returns the estimated duration up to the given frame number,

  // or a 0-duration if unknown.

  media::TimeUnit Duration(int64_t aNumFrames) const;

  // Returns the estimated current seek position time.

  media::TimeUnit SeekPosition() const;

  const FrameParser::Frame& LastFrame() const;

  RefPtr<MediaRawData> DemuxSample();

  const ID3Parser::ID3Header& ID3Header() const;

  const FrameParser::VBRHeader& VBRInfo() const;

  // MediaTrackDemuxer interface.

  UniquePtr<TrackInfo> GetInfo() const override;

  RefPtr<SeekPromise> Seek(const media::TimeUnit& aTime) override;

  RefPtr<SamplesPromise> GetSamples(int32_t aNumSamples = 1) override;

  void Reset() override;

  RefPtr<SkipAccessPointPromise> SkipToNextRandomAccessPoint(

    const media::TimeUnit& aTimeThreshold) override;

  int64_t GetResourceOffset() const override;

  media::TimeIntervals GetBuffered() override;

private:

  // Destructor.

  ~MP3TrackDemuxer() {}

  // Fast approximate seeking to given time.

  media::TimeUnit FastSeek(const media::TimeUnit& aTime);

  // Seeks by scanning the stream up to the given time for more accurate results.

  media::TimeUnit ScanUntil(const media::TimeUnit& aTime);

  // Finds the first valid frame and returns its byte range if found

  // or a null-byte range otherwise.

  MediaByteRange FindFirstFrame();

  // Finds the next valid frame and returns its byte range if found

  // or a null-byte range otherwise.

  MediaByteRange FindNextFrame();

  // Skips the next frame given the provided byte range.

  bool SkipNextFrame(const MediaByteRange& aRange);

  // Returns the next MPEG frame, if available.

  already_AddRefed<MediaRawData> GetNextFrame(const MediaByteRange& aRange);

  // Updates post-read meta data.

  void UpdateState(const MediaByteRange& aRange);

  // Returns the estimated offset for the given frame index.

  int64_t OffsetFromFrameIndex(int64_t aFrameIndex) const;

  // Returns the estimated frame index for the given offset.

  int64_t FrameIndexFromOffset(int64_t aOffset) const;

  // Returns the estimated frame index for the given time.

  int64_t FrameIndexFromTime(const media::TimeUnit& aTime) const;

  // Reads aSize bytes into aBuffer from the source starting at aOffset.

  // Returns the actual size read.

  int32_t Read(uint8_t* aBuffer, int64_t aOffset, int32_t aSize);

  // Returns the average frame length derived from the previously parsed frames.

  double AverageFrameLength() const;

  // The (hopefully) MPEG resource.

  MediaResourceIndex mSource;

  // MPEG frame parser used to detect frames and extract side info.

  FrameParser mParser;

  // Whether we've locked onto a valid sequence of frames or not.

  bool mFrameLock;

  // Current byte offset in the source stream.

  int64_t mOffset;

  // Byte offset of the begin of the first frame, or 0 if none parsed yet.

  int64_t mFirstFrameOffset;

  // Total parsed frames.

  uint64_t mNumParsedFrames;

  // Current frame index.

  int64_t mFrameIndex;

  // Sum of parsed frames' lengths in bytes.

  uint64_t mTotalFrameLen;

  // Samples per frame metric derived from frame headers or 0 if none available.

  int32_t mSamplesPerFrame;

  // Samples per second metric derived from frame headers or 0 if none available.

  int32_t mSamplesPerSecond;

  // Channel count derived from frame headers or 0 if none available.

  int32_t mChannels;

  // Audio track config info.

  UniquePtr<AudioInfo> mInfo;

};

} // namespace mozilla

#endif