Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 374 insertions, 0 deletions

diff --git a/dom/media/mp3/MP3FrameParser.h b/dom/media/mp3/MP3FrameParser.h
new file mode 100644
index 0000000000..d0d7a372d2
--- /dev/null
+++ b/dom/media/mp3/MP3FrameParser.h
@@ -0,0 +1,374 @@
+/* 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_FRAME_PARSER_H_
+#define MP3_FRAME_PARSER_H_
+
+#include <vector>
+
+#include "mozilla/Maybe.h"
+#include "mozilla/Result.h"
+#include "BufferReader.h"
+
+namespace mozilla {
+
+// 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 https://id3.org/id3v2.4.0-structure
+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;
+    static const int ID3v1_SIZE = 128;
+
+    // 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;
+
+    // To see whether we have parsed the value of the size from header.
+    bool HasSizeBeenSet() const;
+
+    // Returns the size of an ID3v2.4 footer if present and zero otherwise.
+    uint8_t FooterSize() const;
+
+    // The total size of the ID3 tag including header/footer, or zero if
+    // none has been found.
+    uint32_t TotalTagSize() 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.
+    Maybe<uint32_t> mSize;
+
+    // The current byte position in the parsed sequence. Reset via Reset and
+    // incremented via Update.
+    int mPos = 0;
+  };
+
+  // Check if the buffer is starting with ID3v2 tag.
+  static bool IsBufferStartingWithID3Tag(BufferReader* aReader);
+  // Similarly, if the buffer is starting with ID3v1 tag.
+  static bool IsBufferStartingWithID3v1Tag(BufferReader* aReader);
+
+  // Returns the parsed ID3 header. Note: check for validity.
+  const ID3Header& Header() const;
+
+  // Returns the size of all parsed ID3 headers.
+  uint32_t TotalHeadersSize() const;
+
+  // Parses contents of given BufferReader for a valid ID3v2 header.
+  // Returns the parsed ID3v2 tag size if successful and zero otherwise.
+  uint32_t Parse(BufferReader* aReader);
+
+  // Resets the state to allow for a new parsing session.
+  void Reset();
+
+ private:
+  uint32_t ParseInternal(BufferReader* aReader);
+
+  // The currently parsed ID3 header. Reset via Reset, updated via Parse.
+  ID3Header mHeader;
+  // If a file contains multiple ID3 headers, then we would only select the
+  // latest one, but keep the size of former abandoned in order to return the
+  // correct size offset.
+  uint32_t mFormerID3Size = 0;
+};
+
+// 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.
+    uint32_t SampleRate() const;
+
+    // Number of audio channels.
+    uint32_t Channels() const;
+
+    // Samples per frames, static depending on MPEG version and layer.
+    uint32_t SamplesPerFrame() const;
+
+    // Slot size used for padding, static depending on MPEG layer.
+    uint32_t SlotSize() const;
+
+    // Bitrate in kbps, can vary between frames.
+    uint32_t Bitrate() const;
+
+    // MPEG layer (0->invalid, 1->I, 2->II, 3->III).
+    uint32_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 = 0;
+  };
+
+  // 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(media::TimeUnit aTime, media::TimeUnit aDuration) 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(BufferReader* aReader, size_t aFrameSize);
+
+    uint32_t EncoderDelay() const { return mEncoderDelay; }
+    uint32_t EncoderPadding() const { return mEncoderPadding; }
+
+   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.
+    Result<bool, nsresult> ParseXing(BufferReader* aReader, size_t aFrameSize);
+
+    // 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.
+    Result<bool, nsresult> ParseVBRI(BufferReader* 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;
+
+    uint16_t mVBRISeekOffsetsFramesPerEntry = 0;
+
+    // Delay and padding values found in the LAME header. The encoder delay is a
+    // number of frames that has to be skipped at the beginning of the stream,
+    // encoder padding is a number of frames that needs to be ignored in the
+    // last packet.
+    uint16_t mEncoderDelay = 0;
+    uint16_t mEncoderPadding = 0;
+  };
+
+  // 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.
+    uint32_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 whether ID3 metadata have been found, at the end of the file.
+  bool ID3v1MetadataFound() const;
+
+  // Returns the size of all parsed ID3 headers.
+  uint32_t TotalID3HeaderSize() 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 BufferReader 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.
+  Result<bool, nsresult> Parse(BufferReader* aReader, uint32_t* aBytesToSkip);
+
+  // Parses contents of given BufferReader for a valid VBR header.
+  // The offset of the passed BufferReader 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(BufferReader* 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;
+  // If this is true, ID3v1 metadata have been found at the end of the file, and
+  // must be sustracted from the stream size in order to compute the stream
+  // duration, when computing the duration of a CBR file based on its length in
+  // bytes. This means that the duration can change at the moment we reach the
+  // end of the file.
+  bool mID3v1MetadataFound = false;
+};
+
+}  // namespace mozilla
+
+#endif