Move the MP3 code to it's own directory

1 files changed, 472 insertions, 0 deletions

diff --git a/dom/media/mp3/MP3Demuxer.h b/dom/media/mp3/MP3Demuxer.h
new file mode 100644
index 000000000..5331c4d54
--- /dev/null
+++ b/dom/media/mp3/MP3Demuxer.h
@@ -0,0 +1,472 @@
+/* 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 "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+#include "MediaDataDemuxer.h"
+#include "MediaResource.h"
+#include "mp4_demuxer/ByteReader.h"
+#include <vector>
+
+namespace mozilla {
+
+class MP3TrackDemuxer;
+
+class MP3Demuxer : public MediaDataDemuxer {
+public:
+  // MediaDataDemuxer interface.
+  explicit MP3Demuxer(MediaResource* aSource);
+  RefPtr<InitPromise> Init() override;
+  bool HasTrackType(TrackInfo::TrackType aType) const 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;
+};
+
+// ID3 header parser state machine used by FrameParser.
+// The header contains the following format (one byte per term):
+// 'I' 'D' '3' MajorVersion MinorVersion Flags Size1 Size2 Size3 Size4
+// For more details see http://id3.org/id3v2.3.0.
+class ID3Parser {
+public:
+  // Holds the ID3 header and its parsing state.
+  class ID3Header {
+  public:
+    // The header size is static, see class comment.
+    static const int SIZE = 10;
+
+    // Constructor.
+    ID3Header();
+
+    // Resets the state to allow for a new parsing session.
+    void Reset();
+
+    // The ID3 tags are versioned like this: ID3vMajorVersion.MinorVersion.
+    uint8_t MajorVersion() const;
+    uint8_t MinorVersion() const;
+
+    // The ID3 flags field.
+    uint8_t Flags() const;
+
+    // The derived size based on the provided size fields.
+    uint32_t Size() const;
+
+    // Returns the size of an ID3v2.4 footer if present and zero otherwise.
+    uint8_t FooterSize() const;
+
+    // Returns whether the parsed data is a valid ID3 header up to the given
+    // byte position.
+    bool IsValid(int aPos) const;
+
+    // Returns whether the parsed data is a complete and valid ID3 header.
+    bool IsValid() const;
+
+    // Parses the next provided byte.
+    // Returns whether the byte creates a valid sequence up to this point.
+    bool ParseNext(uint8_t c);
+
+  private:
+    // Updates the parser state machine with the provided next byte.
+    // Returns whether the provided byte is a valid next byte in the sequence.
+    bool Update(uint8_t c);
+
+    // The currently parsed byte sequence.
+    uint8_t mRaw[SIZE];
+
+    // The derived size as provided by the size fields.
+    // The header size fields holds a 4 byte sequence with each MSB set to 0,
+    // this bits need to be ignored when deriving the actual size.
+    uint32_t mSize;
+
+    // The current byte position in the parsed sequence. Reset via Reset and
+    // incremented via Update.
+    int mPos;
+  };
+
+  // Returns the parsed ID3 header. Note: check for validity.
+  const ID3Header& Header() const;
+
+  // Parses contents of given ByteReader for a valid ID3v2 header.
+  // Returns the total ID3v2 tag size if successful and zero otherwise.
+  uint32_t Parse(mp4_demuxer::ByteReader* aReader);
+
+  // Resets the state to allow for a new parsing session.
+  void Reset();
+
+private:
+  // The currently parsed ID3 header. Reset via Reset, updated via Parse.
+  ID3Header mHeader;
+};
+
+// MPEG audio frame parser.
+// The MPEG frame header has the following format (one bit per character):
+// 11111111 111VVLLC BBBBSSPR MMEETOHH
+// {   sync   } - 11 sync bits
+//   VV         - MPEG audio version ID (0->2.5, 1->reserved, 2->2, 3->1)
+//   LL         - Layer description (0->reserved, 1->III, 2->II, 3->I)
+//   C          - CRC protection bit (0->protected, 1->not protected)
+//   BBBB       - Bitrate index (see table in implementation)
+//   SS         - Sampling rate index (see table in implementation)
+//   P          - Padding bit (0->not padded, 1->padded by 1 slot size)
+//   R          - Private bit (ignored)
+//   MM         - Channel mode (0->stereo, 1->joint stereo, 2->dual channel,
+//                3->single channel)
+//   EE         - Mode extension for joint stereo (ignored)
+//   T          - Copyright (0->disabled, 1->enabled)
+//   O          - Original (0->copy, 1->original)
+//   HH         - Emphasis (0->none, 1->50/15 ms, 2->reserved, 3->CCIT J.17)
+class FrameParser {
+public:
+  // Holds the frame header and its parsing state.
+  class FrameHeader {
+  public:
+    // The header size is static, see class comments.
+    static const int SIZE = 4;
+
+    // Constructor.
+    FrameHeader();
+
+    // Raw field access, see class comments for details.
+    uint8_t Sync1() const;
+    uint8_t Sync2() const;
+    uint8_t RawVersion() const;
+    uint8_t RawLayer() const;
+    uint8_t RawProtection() const;
+    uint8_t RawBitrate() const;
+    uint8_t RawSampleRate() const;
+    uint8_t Padding() const;
+    uint8_t Private() const;
+    uint8_t RawChannelMode() const;
+
+    // Sampling rate frequency in Hz.
+    int32_t SampleRate() const;
+
+    // Number of audio channels.
+    int32_t Channels() const;
+
+    // Samples per frames, static depending on MPEG version and layer.
+    int32_t SamplesPerFrame() const;
+
+    // Slot size used for padding, static depending on MPEG layer.
+    int32_t SlotSize() const;
+
+    // Bitrate in kbps, can vary between frames.
+    int32_t Bitrate() const;
+
+    // MPEG layer (0->invalid, 1->I, 2->II, 3->III).
+    int32_t Layer() const;
+
+    // Returns whether the parsed data is a valid frame header up to the given
+    // byte position.
+    bool IsValid(const int aPos) const;
+
+    // Returns whether the parsed data is a complete and valid frame header.
+    bool IsValid() const;
+
+    // Resets the state to allow for a new parsing session.
+    void Reset();
+
+    // Parses the next provided byte.
+    // Returns whether the byte creates a valid sequence up to this point.
+    bool ParseNext(const uint8_t c);
+
+  private:
+    // Updates the parser state machine with the provided next byte.
+    // Returns whether the provided byte is a valid next byte in the sequence.
+    bool Update(const uint8_t c);
+
+    // The currently parsed byte sequence.
+    uint8_t mRaw[SIZE];
+
+    // The current byte position in the parsed sequence. Reset via Reset and
+    // incremented via Update.
+    int mPos;
+  };
+
+  // VBR frames may contain Xing or VBRI headers for additional info, we use
+  // this class to parse them and access this info.
+  class VBRHeader {
+  public:
+    // Synchronize with vbr_header TYPE_STR on change.
+    enum VBRHeaderType {
+      NONE = 0,
+      XING,
+      VBRI
+    };
+
+    // Constructor.
+    VBRHeader();
+
+    // Returns the parsed VBR header type, or NONE if no valid header found.
+    VBRHeaderType Type() const;
+
+    // Returns the total number of audio frames (excluding the VBR header frame)
+    // expected in the stream/file.
+    const Maybe<uint32_t>& NumAudioFrames() const;
+
+    // Returns the expected size of the stream.
+    const Maybe<uint32_t>& NumBytes() const;
+
+    // Returns the VBR scale factor (0: best quality, 100: lowest quality).
+    const Maybe<uint32_t>& Scale() const;
+
+    // Returns true iff Xing/Info TOC (table of contents) is present.
+    bool IsTOCPresent() const;
+
+    // Returns whether the header is valid (type XING or VBRI).
+    bool IsValid() const;
+
+    // Returns whether the header is valid and contains reasonable non-zero field values.
+    bool IsComplete() const;
+
+    // Returns the byte offset for the given duration percentage as a factor
+    // (0: begin, 1.0: end).
+    int64_t Offset(float aDurationFac) const;
+
+    // Parses contents of given ByteReader for a valid VBR header.
+    // The offset of the passed ByteReader needs to point to an MPEG frame begin,
+    // as a VBRI-style header is searched at a fixed offset relative to frame begin.
+    // Returns whether a valid VBR header was found in the range.
+    bool Parse(mp4_demuxer::ByteReader* aReader);
+
+  private:
+    // Parses contents of given ByteReader for a valid Xing header.
+    // The initial ByteReader offset will be preserved.
+    // Returns whether a valid Xing header was found in the range.
+    bool ParseXing(mp4_demuxer::ByteReader* aReader);
+
+    // Parses contents of given ByteReader for a valid VBRI header.
+    // The initial ByteReader offset will be preserved. It also needs to point
+    // to the beginning of a valid MPEG frame, as VBRI headers are searched
+    // at a fixed offset relative to frame begin.
+    // Returns whether a valid VBRI header was found in the range.
+    bool ParseVBRI(mp4_demuxer::ByteReader* aReader);
+
+    // The total number of frames expected as parsed from a VBR header.
+    Maybe<uint32_t> mNumAudioFrames;
+
+    // The total number of bytes expected in the stream.
+    Maybe<uint32_t> mNumBytes;
+
+    // The VBR scale factor.
+    Maybe<uint32_t> mScale;
+
+    // The TOC table mapping duration percentage to byte offset.
+    std::vector<int64_t> mTOC;
+
+    // The detected VBR header type.
+    VBRHeaderType mType;
+  };
+
+  // Frame meta container used to parse and hold a frame header and side info.
+  class Frame {
+  public:
+    // Returns the length of the frame excluding the header in bytes.
+    int32_t Length() const;
+
+    // Returns the parsed frame header.
+    const FrameHeader& Header() const;
+
+    // Resets the frame header and data.
+    void Reset();
+
+    // Parses the next provided byte.
+    // Returns whether the byte creates a valid sequence up to this point.
+    bool ParseNext(uint8_t c);
+
+  private:
+    // The currently parsed frame header.
+    FrameHeader mHeader;
+  };
+
+  // Constructor.
+  FrameParser();
+
+  // Returns the currently parsed frame. Reset via Reset or EndFrameSession.
+  const Frame& CurrentFrame() const;
+
+  // Returns the previously parsed frame. Reset via Reset.
+  const Frame& PrevFrame() const;
+
+  // Returns the first parsed frame. Reset via Reset.
+  const Frame& FirstFrame() const;
+
+  // Returns the parsed ID3 header. Note: check for validity.
+  const ID3Parser::ID3Header& ID3Header() const;
+
+  // Returns the parsed VBR header info. Note: check for validity by type.
+  const VBRHeader& VBRInfo() const;
+
+  // Resets the parser.
+  void Reset();
+
+  // Resets all frame data, but not the ID3Header.
+  // Don't use between frames as first frame data is reset.
+  void ResetFrameData();
+
+  // Clear the last parsed frame to allow for next frame parsing, i.e.:
+  // - sets PrevFrame to CurrentFrame
+  // - resets the CurrentFrame
+  // - resets ID3Header if no valid header was parsed yet
+  void EndFrameSession();
+
+  // Parses contents of given ByteReader for a valid frame header and returns true
+  // if one was found. After returning, the variable passed to 'aBytesToSkip' holds
+  // the amount of bytes to be skipped (if any) in order to jump across a large
+  // ID3v2 tag spanning multiple buffers.
+  bool Parse(mp4_demuxer::ByteReader* aReader, uint32_t* aBytesToSkip);
+
+  // Parses contents of given ByteReader for a valid VBR header.
+  // The offset of the passed ByteReader needs to point to an MPEG frame begin,
+  // as a VBRI-style header is searched at a fixed offset relative to frame begin.
+  // Returns whether a valid VBR header was found.
+  bool ParseVBRHeader(mp4_demuxer::ByteReader* aReader);
+
+private:
+  // ID3 header parser.
+  ID3Parser mID3Parser;
+
+  // VBR header parser.
+  VBRHeader mVBRHeader;
+
+  // We keep the first parsed frame around for static info access, the
+  // previously parsed frame for debugging and the currently parsed frame.
+  Frame mFirstFrame;
+  Frame mFrame;
+  Frame mPrevFrame;
+};
+
+// The MP3 demuxer used to extract MPEG frames and side information out of
+// MPEG streams.
+class MP3TrackDemuxer : public MediaTrackDemuxer {
+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(media::TimeUnit aTime) override;
+  RefPtr<SamplesPromise> GetSamples(int32_t aNumSamples = 1) override;
+  void Reset() override;
+  RefPtr<SkipAccessPointPromise> SkipToNextRandomAccessPoint(
+    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;
+
+  // 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