Add m-esr52 at 52.6.0

7 files changed, 1603 insertions, 0 deletions

diff --git a/dom/media/flac/FlacDecoder.cpp b/dom/media/flac/FlacDecoder.cpp
new file mode 100644
index 0000000000..3109713dbe
--- /dev/null
+++ b/dom/media/flac/FlacDecoder.cpp
@@ -0,0 +1,52 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+#include "FlacDecoder.h"
+#include "FlacDemuxer.h"
+#include "MediaDecoderStateMachine.h"
+#include "MediaFormatReader.h"
+#include "MediaPrefs.h"
+
+namespace mozilla {
+
+MediaDecoder*
+FlacDecoder::Clone(MediaDecoderOwner* aOwner)
+{
+  if (!IsEnabled())
+    return nullptr;
+
+  return new FlacDecoder(aOwner);
+}
+
+MediaDecoderStateMachine*
+FlacDecoder::CreateStateMachine()
+{
+  RefPtr<MediaDecoderReader> reader =
+      new MediaFormatReader(this, new FlacDemuxer(GetResource()));
+  return new MediaDecoderStateMachine(this, reader);
+}
+
+/* static */ bool
+FlacDecoder::IsEnabled()
+{
+#ifdef MOZ_FFVPX
+  return MediaPrefs::FlacEnabled();
+#else
+  // Until bug 1295886 is fixed.
+  return false;
+#endif
+}
+
+/* static */ bool
+FlacDecoder::CanHandleMediaType(const nsACString& aType,
+                                const nsAString& aCodecs)
+{
+  return IsEnabled() &&
+    (aType.EqualsASCII("audio/flac") || aType.EqualsASCII("audio/x-flac") ||
+     aType.EqualsASCII("application/x-flac"));
+}
+
+} // namespace mozilla
diff --git a/dom/media/flac/FlacDecoder.h b/dom/media/flac/FlacDecoder.h
new file mode 100644
index 0000000000..304ee62f8b
--- /dev/null
+++ b/dom/media/flac/FlacDecoder.h
@@ -0,0 +1,30 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+#ifndef FLAC_DECODER_H_
+#define FLAC_DECODER_H_
+
+#include "MediaDecoder.h"
+
+namespace mozilla {
+
+class FlacDecoder : public MediaDecoder {
+public:
+  // MediaDecoder interface.
+  explicit FlacDecoder(MediaDecoderOwner* aOwner) : MediaDecoder(aOwner) {}
+  MediaDecoder* Clone(MediaDecoderOwner* aOwner) override;
+  MediaDecoderStateMachine* CreateStateMachine() override;
+
+  // Returns true if the Flac backend is pref'ed on, and we're running on a
+  // platform that is likely to have decoders for the format.
+  static bool IsEnabled();
+  static bool CanHandleMediaType(const nsACString& aType,
+                                 const nsAString& aCodecs);
+};
+
+} // namespace mozilla
+
+#endif // !FLAC_DECODER_H_
diff --git a/dom/media/flac/FlacDemuxer.cpp b/dom/media/flac/FlacDemuxer.cpp
new file mode 100644
index 0000000000..7a98edbee6
--- /dev/null
+++ b/dom/media/flac/FlacDemuxer.cpp
@@ -0,0 +1,1074 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+#include "FlacDemuxer.h"
+
+#include "mozilla/Maybe.h"
+#include "mp4_demuxer/BitReader.h"
+#include "nsAutoPtr.h"
+#include "prenv.h"
+#include "FlacFrameParser.h"
+#include "VideoUtils.h"
+#include "TimeUnits.h"
+
+#ifdef PR_LOGGING
+extern mozilla::LazyLogModule gMediaDemuxerLog;
+#define LOG(msg, ...) \
+  MOZ_LOG(gMediaDemuxerLog, LogLevel::Debug, ("FlacDemuxer " msg, ##__VA_ARGS__))
+#define LOGV(msg, ...) \
+  MOZ_LOG(gMediaDemuxerLog, LogLevel::Verbose, ("FlacDemuxer " msg, ##__VA_ARGS__))
+#else
+#define LOG(msg, ...)  do {} while (false)
+#define LOGV(msg, ...) do {} while (false)
+#endif
+
+using namespace mozilla::media;
+
+namespace mozilla {
+namespace flac {
+
+// flac::FrameHeader - Holds the flac frame header and its parsing
+// state.
+
+#define FLAC_MAX_CHANNELS           8
+#define FLAC_MIN_BLOCKSIZE         16
+#define FLAC_MAX_BLOCKSIZE      65535
+#define FLAC_MIN_FRAME_SIZE        11
+#define FLAC_MAX_FRAME_HEADER_SIZE 16
+#define FLAC_MAX_FRAME_SIZE (FLAC_MAX_FRAME_HEADER_SIZE \
+                             +FLAC_MAX_BLOCKSIZE*FLAC_MAX_CHANNELS*3)
+
+class FrameHeader {
+public:
+  const AudioInfo& Info() const { return mInfo; }
+
+  uint32_t Size() const { return mSize; }
+
+  bool IsValid() const { return mValid; }
+
+  // Return the index (in samples) from the beginning of the track.
+  int64_t Index() const { return mIndex; }
+
+  // Parse the current packet and check that it made a valid flac frame header.
+  // From https://xiph.org/flac/format.html#frame_header
+  // A valid header is one that can be decoded without error and that has a
+  // valid CRC.
+  // aPacket must points to a buffer that is at least FLAC_MAX_FRAME_HEADER_SIZE
+  // bytes.
+  bool Parse(const uint8_t* aPacket)
+  {
+    mp4_demuxer::BitReader br(aPacket, FLAC_MAX_FRAME_HEADER_SIZE);
+
+    // Frame sync code.
+    if ((br.ReadBits(15) & 0x7fff) != 0x7ffc) {
+      return false;
+    }
+
+    // Variable block size stream code.
+    mVariableBlockSize = br.ReadBit();
+
+    // Block size and sample rate codes.
+    int bs_code = br.ReadBits(4);
+    int sr_code = br.ReadBits(4);
+
+    // Channels and decorrelation.
+    int ch_mode = br.ReadBits(4);
+    if (ch_mode < FLAC_MAX_CHANNELS) {
+      mInfo.mChannels = ch_mode + 1;
+    } else if (ch_mode < FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE) {
+      // This is a special flac channels, we can't handle those yet. Treat it
+      // as stereo.
+      mInfo.mChannels = 2;
+    } else {
+      // invalid channel mode
+      return false;
+    }
+
+    // Bits per sample.
+    int bps_code = br.ReadBits(3);
+    if (bps_code == 3 || bps_code == 7) {
+      // Invalid sample size code.
+      return false;
+    }
+    mInfo.mBitDepth = FlacSampleSizeTable[bps_code];
+
+    // Reserved bit, most be 1.
+    if (br.ReadBit()) {
+      // Broken stream, invalid padding.
+      return false;
+    }
+
+    // Sample or frame count.
+    int64_t frame_or_sample_num = br.ReadUTF8();
+    if (frame_or_sample_num < 0) {
+      // Sample/frame number invalid.
+      return false;
+    }
+
+    // Blocksize
+    if (bs_code == 0) {
+      // reserved blocksize code
+      return false;
+    } else if (bs_code == 6) {
+      mBlocksize = br.ReadBits(8) + 1;
+    } else if (bs_code == 7) {
+      mBlocksize = br.ReadBits(16) + 1;
+    } else {
+      mBlocksize = FlacBlocksizeTable[bs_code];
+    }
+
+    // The sample index is either:
+    // 1- coded sample number if blocksize is variable or
+    // 2- coded frame number if blocksize is known.
+    // A frame is made of Blocksize sample.
+    mIndex = mVariableBlockSize
+      ? frame_or_sample_num
+      : frame_or_sample_num * mBlocksize;
+
+    // Sample rate.
+    if (sr_code < 12) {
+      mInfo.mRate = FlacSampleRateTable[sr_code];
+    } else if (sr_code == 12) {
+      mInfo.mRate = br.ReadBits(8) * 1000;
+    } else if (sr_code == 13) {
+      mInfo.mRate = br.ReadBits(16);
+    } else if (sr_code == 14) {
+      mInfo.mRate = br.ReadBits(16) * 10;
+    } else {
+      // Illegal sample rate code.
+      return false;
+    }
+
+    // Header CRC-8 check.
+    uint8_t crc = 0;
+    for (uint32_t i = 0; i < br.BitCount() / 8; i++) {
+      crc = CRC8Table[crc ^ aPacket[i]];
+    }
+    mValid = crc == br.ReadBits(8);
+    mSize = br.BitCount() / 8;
+
+    if (mValid) {
+      // Set the mimetype to make it a valid AudioInfo.
+      mInfo.mMimeType = "audio/flac";
+    }
+
+    return mValid;
+  }
+
+private:
+  friend class Frame;
+  enum {
+    FLAC_CHMODE_INDEPENDENT = 0,
+    FLAC_CHMODE_LEFT_SIDE,
+    FLAC_CHMODE_RIGHT_SIDE,
+    FLAC_CHMODE_MID_SIDE,
+  };
+  AudioInfo mInfo;
+  // Index in samples from start;
+  int64_t mIndex = 0;
+  bool mVariableBlockSize = false;
+  uint32_t mBlocksize = 0;;
+  uint32_t mSize = 0;
+  bool mValid = false;
+
+  static const int FlacSampleRateTable[16];
+  static const int32_t FlacBlocksizeTable[16];
+  static const uint8_t FlacSampleSizeTable[8];
+  static const uint8_t CRC8Table[256];
+};
+
+const int FrameHeader::FlacSampleRateTable[16] =
+{ 0,
+  88200, 176400, 192000,
+  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
+  0, 0, 0, 0
+};
+
+const int32_t FrameHeader::FlacBlocksizeTable[16] =
+{
+  0     , 192   , 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
+  256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
+};
+
+const uint8_t FrameHeader::FlacSampleSizeTable[8] = { 0, 8, 12, 0, 16, 20, 24, 0 };
+
+const uint8_t FrameHeader::CRC8Table[256] =
+{
+  0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15,
+  0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,
+  0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
+  0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,
+  0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5,
+  0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
+  0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85,
+  0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,
+  0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
+  0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,
+  0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2,
+  0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
+  0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32,
+  0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,
+  0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
+  0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,
+  0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C,
+  0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
+  0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,
+  0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,
+  0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
+  0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,
+  0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C,
+  0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
+  0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B,
+  0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,
+  0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
+  0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,
+  0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB,
+  0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
+  0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB,
+  0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3
+};
+
+// flac::Frame - Frame meta container used to parse and hold a frame
+// header and side info.
+class Frame {
+public:
+
+  // The FLAC signature is made of 14 bits set to 1; however the 15th bit is
+  // mandatorily set to 0, so we need to find either of 0xfffc or 0xfffd 2-bytes
+  // signature. We first use a bitmask to see if 0xfc or 0xfd is present. And if
+  // so we check for the whole signature.
+  // aData must be pointing to a buffer at least
+  // aLength + FLAC_MAX_FRAME_HEADER_SIZE bytes.
+  int64_t FindNext(const uint8_t* aData, const uint32_t aLength)
+  {
+    uint32_t modOffset = aLength % 4;
+    uint32_t i, j;
+
+    for (i = 0; i < modOffset; i++) {
+      if ((BigEndian::readUint16(aData + i) & 0xfffe) == 0xfff8) {
+        if (mHeader.Parse(aData + i)) {
+          return i;
+        }
+      }
+    }
+
+    for (; i < aLength; i += 4) {
+      uint32_t x = BigEndian::readUint32(aData + i);
+      if (((x & ~(x + 0x01010101)) & 0x80808080)) {
+        for (j = 0; j < 4; j++) {
+          if ((BigEndian::readUint16(aData + i + j) & 0xfffe) == 0xfff8) {
+            if (mHeader.Parse(aData + i + j)) {
+              return i + j;
+            }
+          }
+        }
+      }
+    }
+    return -1;
+  }
+
+  // Find the next frame start in the current resource.
+  // On exit return true, offset is set and resource points to the frame found.
+  bool FindNext(MediaResourceIndex& aResource)
+  {
+    static const int BUFFER_SIZE = 4096;
+
+    Reset();
+
+    nsTArray<char> buffer;
+    int64_t originalOffset = aResource.Tell();
+    int64_t offset = originalOffset;
+    uint32_t innerOffset = 0;
+
+    do {
+      uint32_t read = 0;
+      buffer.SetLength(BUFFER_SIZE + innerOffset);
+      nsresult rv =
+        aResource.Read(buffer.Elements() + innerOffset, BUFFER_SIZE, &read);
+      if (NS_FAILED(rv)) {
+        return false;
+      }
+
+      if (read < FLAC_MAX_FRAME_HEADER_SIZE) {
+        // Assume that we can't have a valid frame in such small content, we
+        // must have reached EOS.
+        // So we're done.
+        mEOS = true;
+        return false;
+      }
+
+      const size_t bufSize = read + innerOffset - FLAC_MAX_FRAME_HEADER_SIZE;
+      int64_t foundOffset =
+        FindNext(reinterpret_cast<uint8_t*>(buffer.Elements()), bufSize);
+
+      if (foundOffset >= 0) {
+        SetOffset(aResource, foundOffset + offset);
+        return true;
+      }
+
+      // Scan the next block;
+      offset += bufSize;
+      buffer.RemoveElementsAt(0, bufSize);
+      innerOffset = buffer.Length();
+    } while (offset - originalOffset < FLAC_MAX_FRAME_SIZE);
+
+    return false;
+  }
+
+  int64_t Offset() const { return mOffset; }
+
+  const AudioInfo& Info() const { return Header().Info(); }
+
+  void SetEndOffset(int64_t aOffset) { mSize = aOffset - mOffset; }
+
+  void SetEndTime(int64_t aIndex)
+  {
+    if (aIndex > Header().mIndex) {
+      mDuration = aIndex - Header().mIndex;
+    }
+  }
+
+  uint32_t Size() const { return mSize; }
+
+  TimeUnit Time() const
+  {
+    if (!IsValid()) {
+      return TimeUnit::Invalid();
+    }
+    MOZ_ASSERT(Header().Info().mRate, "Invalid Frame. Need Header");
+    return FramesToTimeUnit(Header().mIndex, Header().Info().mRate);
+  }
+
+  TimeUnit Duration() const
+  {
+    if (!IsValid()) {
+      return TimeUnit();
+    }
+    MOZ_ASSERT(Header().Info().mRate, "Invalid Frame. Need Header");
+    return FramesToTimeUnit(mDuration, Header().Info().mRate);
+  }
+
+  // Returns the parsed frame header.
+  const FrameHeader& Header() const { return mHeader; }
+
+  bool IsValid() const { return mHeader.IsValid(); }
+
+  bool EOS() const { return mEOS; }
+
+  void SetRate(uint32_t aRate) { mHeader.mInfo.mRate = aRate; };
+
+  void SetBitDepth(uint32_t aBitDepth) { mHeader.mInfo.mBitDepth = aBitDepth; }
+
+  void SetInvalid() { mHeader.mValid = false; }
+
+  // Resets the frame header and data.
+  void Reset() { *this = Frame(); }
+
+private:
+  void SetOffset(MediaResourceIndex& aResource, int64_t aOffset)
+  {
+    mOffset = aOffset;
+    aResource.Seek(SEEK_SET, mOffset);
+  }
+
+  // The offset to the start of the header.
+  int64_t mOffset = 0;
+  uint32_t mSize = 0;
+  uint32_t mDuration = 0;
+  bool mEOS = false;
+
+  // The currently parsed frame header.
+  FrameHeader mHeader;
+
+};
+
+class FrameParser {
+public:
+
+  // Returns the currently parsed frame. Reset via EndFrameSession.
+  const Frame& CurrentFrame() const { return mFrame; }
+
+  // Returns the first parsed frame.
+  const Frame& FirstFrame() const { return mFirstFrame; }
+
+  // Clear the last parsed frame to allow for next frame parsing
+  void EndFrameSession()
+  {
+    mNextFrame.Reset();
+    mFrame.Reset();
+  }
+
+  // Attempt to find the next frame.
+  bool FindNextFrame(MediaResourceIndex& aResource)
+  {
+    mFrame = mNextFrame;
+    if (GetNextFrame(aResource)) {
+      if (!mFrame.IsValid()) {
+        mFrame = mNextFrame;
+        // We need two frames to be able to start playing (or have reached EOS).
+        GetNextFrame(aResource);
+      }
+    }
+
+    if (mFrame.IsValid()) {
+      if (mNextFrame.EOS()) {
+        mFrame.SetEndOffset(aResource.Tell());
+      } else if (mNextFrame.IsValid()) {
+        mFrame.SetEndOffset(mNextFrame.Offset());
+        mFrame.SetEndTime(mNextFrame.Header().Index());
+      }
+    }
+
+    if (!mFirstFrame.IsValid()) {
+      mFirstFrame = mFrame;
+    }
+    return mFrame.IsValid();
+  }
+
+  // Convenience methods to external FlacFrameParser ones.
+  bool IsHeaderBlock(const uint8_t* aPacket, size_t aLength) const
+  {
+    return mParser.IsHeaderBlock(aPacket, aLength);
+  }
+
+  uint32_t HeaderBlockLength(const uint8_t* aPacket) const
+  {
+    return mParser.HeaderBlockLength(aPacket);
+  }
+
+  bool DecodeHeaderBlock(const uint8_t* aPacket, size_t aLength)
+  {
+    return mParser.DecodeHeaderBlock(aPacket, aLength);
+  }
+
+  bool HasFullMetadata() const { return mParser.HasFullMetadata(); }
+
+  AudioInfo Info() const { return mParser.mInfo; }
+
+  // Return a hash table with tag metadata.
+  MetadataTags* GetTags() const { return mParser.GetTags(); }
+
+private:
+  bool GetNextFrame(MediaResourceIndex& aResource)
+  {
+    while (mNextFrame.FindNext(aResource)) {
+      // Move our offset slightly, so that we don't find the same frame at the
+      // next FindNext call.
+      aResource.Seek(SEEK_CUR, mNextFrame.Header().Size());
+      if (mFrame.IsValid()
+          && mNextFrame.Offset() - mFrame.Offset() < FLAC_MAX_FRAME_SIZE
+          && !CheckCRC16AtOffset(mFrame.Offset(),
+                                 mNextFrame.Offset(),
+                                 aResource)) {
+        // The frame doesn't match its CRC or would be too far, skip it..
+        continue;
+      }
+      CheckFrameData();
+      break;
+    }
+    return mNextFrame.IsValid();
+  }
+
+  bool CheckFrameData()
+  {
+    if (mNextFrame.Header().Info().mRate == 0
+        || mNextFrame.Header().Info().mBitDepth == 0) {
+      if (!Info().IsValid()) {
+        // We can only use the STREAMINFO data if we have one.
+        mNextFrame.SetInvalid();
+      } else {
+        if (mNextFrame.Header().Info().mRate == 0) {
+          mNextFrame.SetRate(Info().mRate);
+        }
+        if (mNextFrame.Header().Info().mBitDepth == 0) {
+          mNextFrame.SetBitDepth(Info().mBitDepth);
+        }
+      }
+    }
+    return mNextFrame.IsValid();
+  }
+
+  bool CheckCRC16AtOffset(int64_t aStart, int64_t aEnd,
+                          MediaResourceIndex& aResource) const
+  {
+    int64_t size = aEnd - aStart;
+    if (size <= 0) {
+      return false;
+    }
+    UniquePtr<char[]> buffer(new char[size]);
+    uint32_t read = 0;
+    if (NS_FAILED(aResource.ReadAt(aStart, buffer.get(),
+                                   size, &read))
+        || read != size) {
+      NS_WARNING("Couldn't read frame content");
+      return false;
+    }
+
+    uint16_t crc = 0;
+    uint8_t* buf = reinterpret_cast<uint8_t*>(buffer.get());
+    const uint8_t *end = buf + size;
+    while (buf < end) {
+      crc = CRC16Table[((uint8_t)crc) ^ *buf++] ^ (crc >> 8);
+    }
+    return !crc;
+  }
+
+  const uint16_t CRC16Table[256] =
+  {
+    0x0000, 0x0580, 0x0F80, 0x0A00, 0x1B80, 0x1E00, 0x1400, 0x1180,
+    0x3380, 0x3600, 0x3C00, 0x3980, 0x2800, 0x2D80, 0x2780, 0x2200,
+    0x6380, 0x6600, 0x6C00, 0x6980, 0x7800, 0x7D80, 0x7780, 0x7200,
+    0x5000, 0x5580, 0x5F80, 0x5A00, 0x4B80, 0x4E00, 0x4400, 0x4180,
+    0xC380, 0xC600, 0xCC00, 0xC980, 0xD800, 0xDD80, 0xD780, 0xD200,
+    0xF000, 0xF580, 0xFF80, 0xFA00, 0xEB80, 0xEE00, 0xE400, 0xE180,
+    0xA000, 0xA580, 0xAF80, 0xAA00, 0xBB80, 0xBE00, 0xB400, 0xB180,
+    0x9380, 0x9600, 0x9C00, 0x9980, 0x8800, 0x8D80, 0x8780, 0x8200,
+    0x8381, 0x8601, 0x8C01, 0x8981, 0x9801, 0x9D81, 0x9781, 0x9201,
+    0xB001, 0xB581, 0xBF81, 0xBA01, 0xAB81, 0xAE01, 0xA401, 0xA181,
+    0xE001, 0xE581, 0xEF81, 0xEA01, 0xFB81, 0xFE01, 0xF401, 0xF181,
+    0xD381, 0xD601, 0xDC01, 0xD981, 0xC801, 0xCD81, 0xC781, 0xC201,
+    0x4001, 0x4581, 0x4F81, 0x4A01, 0x5B81, 0x5E01, 0x5401, 0x5181,
+    0x7381, 0x7601, 0x7C01, 0x7981, 0x6801, 0x6D81, 0x6781, 0x6201,
+    0x2381, 0x2601, 0x2C01, 0x2981, 0x3801, 0x3D81, 0x3781, 0x3201,
+    0x1001, 0x1581, 0x1F81, 0x1A01, 0x0B81, 0x0E01, 0x0401, 0x0181,
+    0x0383, 0x0603, 0x0C03, 0x0983, 0x1803, 0x1D83, 0x1783, 0x1203,
+    0x3003, 0x3583, 0x3F83, 0x3A03, 0x2B83, 0x2E03, 0x2403, 0x2183,
+    0x6003, 0x6583, 0x6F83, 0x6A03, 0x7B83, 0x7E03, 0x7403, 0x7183,
+    0x5383, 0x5603, 0x5C03, 0x5983, 0x4803, 0x4D83, 0x4783, 0x4203,
+    0xC003, 0xC583, 0xCF83, 0xCA03, 0xDB83, 0xDE03, 0xD403, 0xD183,
+    0xF383, 0xF603, 0xFC03, 0xF983, 0xE803, 0xED83, 0xE783, 0xE203,
+    0xA383, 0xA603, 0xAC03, 0xA983, 0xB803, 0xBD83, 0xB783, 0xB203,
+    0x9003, 0x9583, 0x9F83, 0x9A03, 0x8B83, 0x8E03, 0x8403, 0x8183,
+    0x8002, 0x8582, 0x8F82, 0x8A02, 0x9B82, 0x9E02, 0x9402, 0x9182,
+    0xB382, 0xB602, 0xBC02, 0xB982, 0xA802, 0xAD82, 0xA782, 0xA202,
+    0xE382, 0xE602, 0xEC02, 0xE982, 0xF802, 0xFD82, 0xF782, 0xF202,
+    0xD002, 0xD582, 0xDF82, 0xDA02, 0xCB82, 0xCE02, 0xC402, 0xC182,
+    0x4382, 0x4602, 0x4C02, 0x4982, 0x5802, 0x5D82, 0x5782, 0x5202,
+    0x7002, 0x7582, 0x7F82, 0x7A02, 0x6B82, 0x6E02, 0x6402, 0x6182,
+    0x2002, 0x2582, 0x2F82, 0x2A02, 0x3B82, 0x3E02, 0x3402, 0x3182,
+    0x1382, 0x1602, 0x1C02, 0x1982, 0x0802, 0x0D82, 0x0782, 0x0202,
+  };
+
+  FlacFrameParser mParser;
+  // We keep the first parsed frame around for static info access
+  // and the currently parsed frame.
+  Frame mFirstFrame;
+  Frame mNextFrame;
+  Frame mFrame;
+};
+
+} // namespace flac
+
+// FlacDemuxer
+
+FlacDemuxer::FlacDemuxer(MediaResource* aSource)
+  : mSource(aSource)
+{}
+
+bool
+FlacDemuxer::InitInternal()
+{
+  if (!mTrackDemuxer) {
+    mTrackDemuxer = new FlacTrackDemuxer(mSource);
+  }
+  return mTrackDemuxer->Init();
+}
+
+RefPtr<FlacDemuxer::InitPromise>
+FlacDemuxer::Init()
+{
+  if (!InitInternal()) {
+    LOG("Init() failure: waiting for data");
+
+    return InitPromise::CreateAndReject(
+      NS_ERROR_DOM_MEDIA_DEMUXER_ERR, __func__);
+  }
+
+  LOG("Init() successful");
+  return InitPromise::CreateAndResolve(NS_OK, __func__);
+}
+
+bool
+FlacDemuxer::HasTrackType(TrackInfo::TrackType aType) const
+{
+  return aType == TrackInfo::kAudioTrack;
+}
+
+uint32_t
+FlacDemuxer::GetNumberTracks(TrackInfo::TrackType aType) const
+{
+  return (aType == TrackInfo::kAudioTrack) ? 1 : 0;
+}
+
+already_AddRefed<MediaTrackDemuxer>
+FlacDemuxer::GetTrackDemuxer(TrackInfo::TrackType aType, uint32_t aTrackNumber)
+{
+  if (!mTrackDemuxer) {
+    return nullptr;
+  }
+
+  return RefPtr<FlacTrackDemuxer>(mTrackDemuxer).forget();
+}
+
+bool
+FlacDemuxer::IsSeekable() const
+{
+  return mTrackDemuxer && mTrackDemuxer->IsSeekable();
+}
+
+// FlacTrackDemuxer
+FlacTrackDemuxer::FlacTrackDemuxer(MediaResource* aSource)
+  : mSource(aSource)
+  , mParser(new flac::FrameParser())
+  , mTotalFrameLen(0)
+{
+  Reset();
+}
+
+FlacTrackDemuxer::~FlacTrackDemuxer()
+{
+}
+
+bool
+FlacTrackDemuxer::Init()
+{
+  static const int BUFFER_SIZE = 4096;
+
+  // First check if we have a valid Flac start.
+  char buffer[BUFFER_SIZE];
+  const uint8_t* ubuffer = reinterpret_cast<uint8_t*>(buffer); // only needed due to type constraints of ReadAt.
+  int64_t offset = 0;
+
+  do {
+    uint32_t read = 0;
+    nsresult ret = mSource.ReadAt(offset, buffer, BUFFER_SIZE, &read);
+    if (NS_FAILED(ret) || read < BUFFER_SIZE) {
+      // Assume that if we can't read that many bytes while parsing the header,
+      // that something is wrong.
+      return false;
+    }
+    if (!mParser->IsHeaderBlock(ubuffer, BUFFER_SIZE)) {
+      // Not a header and we haven't reached the end of the metadata blocks.
+      // Will fall back to using the frames header instead.
+      break;
+    }
+    uint32_t sizeHeader = mParser->HeaderBlockLength(ubuffer);
+    RefPtr<MediaByteBuffer> block =
+      mSource.MediaReadAt(offset, sizeHeader);
+    if (!block || block->Length() != sizeHeader) {
+      break;
+    }
+    if (!mParser->DecodeHeaderBlock(block->Elements(), sizeHeader)) {
+      break;
+    }
+    offset += sizeHeader;
+  } while (!mParser->HasFullMetadata());
+
+  // First flac frame is found after the metadata.
+  // Can seek there immediately to avoid reparsing it all.
+  mSource.Seek(SEEK_SET, offset);
+
+  // Find the first frame to fully initialise our parser.
+  if (mParser->FindNextFrame(mSource)) {
+    // Ensure that the next frame returned will be the first.
+    mSource.Seek(SEEK_SET, mParser->FirstFrame().Offset());
+    mParser->EndFrameSession();
+  } else if (!mParser->Info().IsValid() || !mParser->FirstFrame().IsValid()) {
+    // We must find at least a frame to determine the metadata.
+    // We can't play this stream.
+    return false;
+  }
+
+  if (!mParser->Info().IsValid() || !mParser->Info().mDuration) {
+    // Check if we can look at the last frame for the end time to determine the
+    // duration when we don't have any.
+    TimeAtEnd();
+  }
+
+  return true;
+}
+
+UniquePtr<TrackInfo>
+FlacTrackDemuxer::GetInfo() const
+{
+  if (mParser->Info().IsValid()) {
+    // We have a proper metadata header.
+    UniquePtr<TrackInfo> info = mParser->Info().Clone();
+    nsAutoPtr<MetadataTags> tags(mParser->GetTags());
+    if (tags) {
+      for (auto iter = tags->Iter(); !iter.Done(); iter.Next()) {
+        info->mTags.AppendElement(MetadataTag(iter.Key(), iter.Data()));
+      }
+    }
+    return info;
+  } else if (mParser->FirstFrame().Info().IsValid()) {
+    // Use the first frame header.
+    UniquePtr<TrackInfo> info = mParser->FirstFrame().Info().Clone();
+    info->mDuration = Duration().ToMicroseconds();
+    return info;
+  }
+  return nullptr;
+}
+
+bool
+FlacTrackDemuxer::IsSeekable() const
+{
+  // For now we only allow seeking if a STREAMINFO block was found and with
+  // a known number of samples (duration is set).
+  return mParser->Info().IsValid() && mParser->Info().mDuration;
+}
+
+RefPtr<FlacTrackDemuxer::SeekPromise>
+FlacTrackDemuxer::Seek(TimeUnit aTime)
+{
+  // Efficiently seek to the position.
+  FastSeek(aTime);
+  // Correct seek position by scanning the next frames.
+  const TimeUnit seekTime = ScanUntil(aTime);
+
+  return SeekPromise::CreateAndResolve(seekTime, __func__);
+}
+
+TimeUnit
+FlacTrackDemuxer::FastSeek(const TimeUnit& aTime)
+{
+  LOG("FastSeek(%f) avgFrameLen=%f mParsedFramesDuration=%f offset=%lld",
+      aTime.ToSeconds(), AverageFrameLength(),
+      mParsedFramesDuration.ToSeconds(), GetResourceOffset());
+
+  // Invalidate current frames in the parser.
+  mParser->EndFrameSession();
+
+  if (!mParser->FirstFrame().IsValid()) {
+    // Something wrong, and there's nothing to seek to anyway, so we can
+    // do whatever here.
+    mSource.Seek(SEEK_SET, 0);
+    return TimeUnit();
+  }
+
+  if (aTime <= mParser->FirstFrame().Time()) {
+    // We're attempting to seek prior the first frame, return the first frame.
+    mSource.Seek(SEEK_SET, mParser->FirstFrame().Offset());
+    return mParser->FirstFrame().Time();
+  }
+
+  // We look for the seek position using a bisection search, starting where the
+  // estimated position might be using the average frame length.
+  // Typically, with flac such approximation is typically useless.
+
+  // Estimate where the position might be.
+  int64_t pivot =
+    aTime.ToSeconds() * AverageFrameLength() + mParser->FirstFrame().Offset();
+
+  // Time in seconds where we can stop seeking and will continue using ScanUntil.
+  static const int GAP_THRESHOLD = 5;
+  int64_t first = mParser->FirstFrame().Offset();
+  int64_t last = mSource.GetLength();
+  Maybe<int64_t> lastFoundOffset;
+  uint32_t iterations = 0;
+  TimeUnit timeSeekedTo;
+
+  do {
+    iterations++;
+    mSource.Seek(SEEK_SET, pivot);
+    flac::Frame frame;
+    if (!frame.FindNext(mSource)) {
+      NS_WARNING("We should have found a point");
+      break;
+    }
+    timeSeekedTo = frame.Time();
+
+    LOGV("FastSeek: interation:%u found:%f @ %lld",
+         iterations, timeSeekedTo.ToSeconds(), frame.Offset());
+
+    if (lastFoundOffset && lastFoundOffset.ref() == frame.Offset()) {
+      // Same frame found twice. We're done.
+      break;
+    }
+    lastFoundOffset = Some(frame.Offset());
+
+    if (frame.Time() == aTime) {
+      break;
+    }
+    if (aTime > frame.Time()
+        && aTime - frame.Time() <= TimeUnit::FromSeconds(GAP_THRESHOLD)) {
+      // We're close enough to the target, experimentation shows that bisection
+      // search doesn't help much after that.
+      break;
+    }
+    if (frame.Time() > aTime) {
+      last = pivot;
+      pivot -= (pivot - first) / 2;
+    } else {
+      first = pivot;
+      pivot += (last - pivot) / 2;
+    }
+  } while (true);
+
+  if (lastFoundOffset) {
+    mSource.Seek(SEEK_SET, lastFoundOffset.ref());
+  }
+
+  return timeSeekedTo;
+}
+
+TimeUnit
+FlacTrackDemuxer::ScanUntil(const TimeUnit& aTime)
+{
+  LOG("ScanUntil(%f avgFrameLen=%f mParsedFramesDuration=%f offset=%lld",
+      aTime.ToSeconds(), AverageFrameLength(),
+      mParsedFramesDuration.ToSeconds(), mParser->CurrentFrame().Offset());
+
+   if (!mParser->FirstFrame().IsValid()
+       || aTime <= mParser->FirstFrame().Time()) {
+     return FastSeek(aTime);
+   }
+
+  int64_t previousOffset = 0;
+  TimeUnit previousTime;
+  while (FindNextFrame().IsValid() && mParser->CurrentFrame().Time() < aTime) {
+    previousOffset = mParser->CurrentFrame().Offset();
+    previousTime = mParser->CurrentFrame().Time();
+  }
+
+  if (!mParser->CurrentFrame().IsValid()) {
+    // We reached EOS.
+    return Duration();
+  }
+
+  // Seek back to the last frame found prior the target.
+  mParser->EndFrameSession();
+  mSource.Seek(SEEK_SET, previousOffset);
+  return previousTime;
+}
+
+RefPtr<FlacTrackDemuxer::SamplesPromise>
+FlacTrackDemuxer::GetSamples(int32_t aNumSamples)
+{
+  LOGV("GetSamples(%d) Begin offset=%lld mParsedFramesDuration=%f"
+       " mTotalFrameLen=%llu",
+       aNumSamples, GetResourceOffset(), mParsedFramesDuration.ToSeconds(),
+       mTotalFrameLen);
+
+  if (!aNumSamples) {
+    return SamplesPromise::CreateAndReject(
+      NS_ERROR_DOM_MEDIA_DEMUXER_ERR, __func__);
+  }
+
+  RefPtr<SamplesHolder> frames = new SamplesHolder();
+
+  while (aNumSamples--) {
+    RefPtr<MediaRawData> frame(GetNextFrame(FindNextFrame()));
+    if (!frame)
+      break;
+
+    frames->mSamples.AppendElement(frame);
+  }
+
+  LOGV("GetSamples() End mSamples.Length=%u aNumSamples=%d offset=%lld"
+       " mParsedFramesDuration=%f mTotalFrameLen=%llu",
+       frames->mSamples.Length(), aNumSamples, GetResourceOffset(),
+       mParsedFramesDuration.ToSeconds(), mTotalFrameLen);
+
+  if (frames->mSamples.IsEmpty()) {
+    return SamplesPromise::CreateAndReject(
+      NS_ERROR_DOM_MEDIA_END_OF_STREAM, __func__);
+  }
+
+  return SamplesPromise::CreateAndResolve(frames, __func__);
+}
+
+void
+FlacTrackDemuxer::Reset()
+{
+  LOG("Reset()");
+  MOZ_ASSERT(mParser);
+  if (mParser->FirstFrame().IsValid()) {
+    mSource.Seek(SEEK_SET, mParser->FirstFrame().Offset());
+  } else {
+    mSource.Seek(SEEK_SET, 0);
+  }
+  mParser->EndFrameSession();
+}
+
+RefPtr<FlacTrackDemuxer::SkipAccessPointPromise>
+FlacTrackDemuxer::SkipToNextRandomAccessPoint(TimeUnit aTimeThreshold)
+{
+  // Will not be called for audio-only resources.
+  return SkipAccessPointPromise::CreateAndReject(
+    SkipFailureHolder(NS_ERROR_DOM_MEDIA_DEMUXER_ERR, 0), __func__);
+}
+
+int64_t
+FlacTrackDemuxer::GetResourceOffset() const
+{
+  return mSource.Tell();
+}
+
+TimeIntervals
+FlacTrackDemuxer::GetBuffered()
+{
+  TimeUnit duration = Duration();
+
+  if (duration <= TimeUnit()) {
+    return TimeIntervals();
+  }
+
+  // We could simply parse the cached data instead and read the timestamps.
+  // However, for now this will do.
+  AutoPinned<MediaResource> stream(mSource.GetResource());
+  return GetEstimatedBufferedTimeRanges(stream, duration.ToMicroseconds());
+}
+
+const flac::Frame&
+FlacTrackDemuxer::FindNextFrame()
+{
+  LOGV("FindNext() Begin offset=%lld mParsedFramesDuration=%f"
+       " mTotalFrameLen=%llu",
+       GetResourceOffset(), mParsedFramesDuration.ToSeconds(), mTotalFrameLen);
+
+  if (mParser->FindNextFrame(mSource)) {
+    // Update our current progress stats.
+    mParsedFramesDuration =
+      std::max(mParsedFramesDuration,
+               mParser->CurrentFrame().Time() - mParser->FirstFrame().Time()
+               + mParser->CurrentFrame().Duration());
+    mTotalFrameLen =
+      std::max<uint64_t>(mTotalFrameLen,
+                         mParser->CurrentFrame().Offset()
+                         - mParser->FirstFrame().Offset()
+                         + mParser->CurrentFrame().Size());
+
+    LOGV("FindNext() End time=%f offset=%lld mParsedFramesDuration=%f"
+         " mTotalFrameLen=%llu",
+         mParser->CurrentFrame().Time().ToSeconds(), GetResourceOffset(),
+         mParsedFramesDuration.ToSeconds(), mTotalFrameLen);
+  }
+
+  return mParser->CurrentFrame();
+}
+
+already_AddRefed<MediaRawData>
+FlacTrackDemuxer::GetNextFrame(const flac::Frame& aFrame)
+{
+  if (!aFrame.IsValid()) {
+    LOG("GetNextFrame() EOS");
+    return nullptr;
+  }
+
+  LOG("GetNextFrame() Begin(time=%f offset=%lld size=%u)",
+      aFrame.Time().ToSeconds(), aFrame.Offset(), aFrame.Size());
+
+  const int64_t offset = aFrame.Offset();
+  const uint32_t size = aFrame.Size();
+
+  RefPtr<MediaRawData> frame = new MediaRawData();
+  frame->mOffset = offset;
+
+  nsAutoPtr<MediaRawDataWriter> frameWriter(frame->CreateWriter());
+  if (!frameWriter->SetSize(size)) {
+    LOG("GetNext() Exit failed to allocated media buffer");
+    return nullptr;
+  }
+
+  const uint32_t read = Read(frameWriter->Data(), offset, size);
+  if (read != size) {
+    LOG("GetNextFrame() Exit read=%u frame->Size=%u", read, frame->Size());
+    return nullptr;
+  }
+
+  frame->mTime = aFrame.Time().ToMicroseconds();
+  frame->mDuration = aFrame.Duration().ToMicroseconds();
+  frame->mTimecode = frame->mTime;
+  frame->mOffset = aFrame.Offset();
+  frame->mKeyframe = true;
+
+  MOZ_ASSERT(frame->mTime >= 0);
+  MOZ_ASSERT(frame->mDuration >= 0);
+
+  return frame.forget();
+}
+
+int32_t
+FlacTrackDemuxer::Read(uint8_t* aBuffer, int64_t aOffset, int32_t aSize)
+{
+  uint32_t read = 0;
+  const nsresult rv = mSource.ReadAt(aOffset, reinterpret_cast<char*>(aBuffer),
+                                     static_cast<uint32_t>(aSize), &read);
+  NS_ENSURE_SUCCESS(rv, 0);
+  return static_cast<int32_t>(read);
+}
+
+double
+FlacTrackDemuxer::AverageFrameLength() const
+{
+  if (mParsedFramesDuration.ToMicroseconds()) {
+    return mTotalFrameLen / mParsedFramesDuration.ToSeconds();
+  }
+
+  return 0.0;
+}
+
+TimeUnit
+FlacTrackDemuxer::Duration() const
+{
+  return std::max(mParsedFramesDuration,
+                  TimeUnit::FromMicroseconds(mParser->Info().mDuration));
+}
+
+TimeUnit
+FlacTrackDemuxer::TimeAtEnd()
+{
+  // Scan the last 128kB if available to determine the last frame.
+  static const int OFFSET_FROM_END = 128 * 1024;
+
+  // Seek to the end of the file and attempt to find the last frame.
+  MediaResourceIndex source(mSource.GetResource());
+  TimeUnit previousDuration;
+  TimeUnit previousTime;
+
+  const int64_t streamLen = mSource.GetLength();
+  if (streamLen < 0) {
+    return TimeUnit::FromInfinity();
+  }
+
+  flac::FrameParser parser;
+
+  source.Seek(SEEK_SET, std::max<int64_t>(0LL, streamLen - OFFSET_FROM_END));
+  while (parser.FindNextFrame(source)) {
+    // FFmpeg flac muxer can generate a last frame with earlier than the others.
+    previousTime = std::max(previousTime, parser.CurrentFrame().Time());
+    if (parser.CurrentFrame().Duration() > TimeUnit()) {
+      // The last frame doesn't have a duration, so only update our duration
+      // if we do have one.
+      previousDuration = parser.CurrentFrame().Duration();
+    }
+    if (source.Tell() >= streamLen) {
+      // Limit the read, in case the length change half-way.
+      break;
+    }
+  }
+
+  // Update our current progress stats.
+  mParsedFramesDuration =
+    previousTime + previousDuration - mParser->FirstFrame().Time();
+  mTotalFrameLen = streamLen - mParser->FirstFrame().Offset();
+
+  return mParsedFramesDuration;
+}
+
+/* static */ bool
+FlacDemuxer::FlacSniffer(const uint8_t* aData, const uint32_t aLength)
+{
+  if (aLength < FLAC_MAX_FRAME_HEADER_SIZE) {
+    return false;
+  }
+
+  flac::Frame frame;
+  return frame.FindNext(aData, aLength - FLAC_MAX_FRAME_HEADER_SIZE) >= 0;
+}
+
+} // namespace mozilla
diff --git a/dom/media/flac/FlacDemuxer.h b/dom/media/flac/FlacDemuxer.h
new file mode 100644
index 0000000000..fd0e35c94e
--- /dev/null
+++ b/dom/media/flac/FlacDemuxer.h
@@ -0,0 +1,108 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+#ifndef FLAC_DEMUXER_H_
+#define FLAC_DEMUXER_H_
+
+#include "mozilla/Attributes.h"
+#include "MediaDataDemuxer.h"
+#include "MediaResource.h"
+namespace mozilla {
+
+namespace flac {
+class Frame;
+class FrameParser;
+}
+class FlacTrackDemuxer;
+
+
+class FlacDemuxer : public MediaDataDemuxer {
+public:
+  // MediaDataDemuxer interface.
+  explicit FlacDemuxer(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;
+
+  // Return true if a valid flac frame header could be found.
+  static bool FlacSniffer(const uint8_t* aData, const uint32_t aLength);
+
+private:
+  bool InitInternal();
+
+  RefPtr<MediaResource> mSource;
+  RefPtr<FlacTrackDemuxer> mTrackDemuxer;
+};
+
+class FlacTrackDemuxer : public MediaTrackDemuxer {
+public:
+  explicit FlacTrackDemuxer(MediaResource* aSource);
+
+  // Initializes the track demuxer by reading the first frame for meta data.
+  // Returns initialization success state.
+  bool Init();
+
+  // 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;
+  int64_t GetResourceOffset() const override;
+  media::TimeIntervals GetBuffered() override;
+  RefPtr<SkipAccessPointPromise> SkipToNextRandomAccessPoint(
+    media::TimeUnit aTimeThreshold) override;
+
+  bool IsSeekable() const;
+
+private:
+  // Destructor.
+  ~FlacTrackDemuxer();
+
+  // Returns the estimated stream duration, or a 0-duration if unknown.
+  media::TimeUnit Duration() const;
+  media::TimeUnit TimeAtEnd();
+
+  // 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 next valid frame and return it.
+  const flac::Frame& FindNextFrame();
+
+  // Returns the next ADTS frame, if available.
+  already_AddRefed<MediaRawData> GetNextFrame(const flac::Frame& aFrame);
+
+  // 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) Flac resource.
+  MediaResourceIndex mSource;
+
+  // Flac frame parser used to detect frames and extract side info.
+  nsAutoPtr<flac::FrameParser> mParser;
+
+  // Total duration of parsed frames.
+  media::TimeUnit mParsedFramesDuration;
+
+  // Sum of parsed frames' lengths in bytes.
+  uint64_t mTotalFrameLen;
+
+  // Audio track config info.
+  UniquePtr<AudioInfo> mInfo;
+};
+
+} // mozilla
+
+#endif // !FLAC_DEMUXER_H_
diff --git a/dom/media/flac/FlacFrameParser.cpp b/dom/media/flac/FlacFrameParser.cpp
new file mode 100644
index 0000000000..f2d6c1367e
--- /dev/null
+++ b/dom/media/flac/FlacFrameParser.cpp
@@ -0,0 +1,251 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+#include "FlacFrameParser.h"
+#include "mp4_demuxer/ByteReader.h"
+#include "nsTArray.h"
+#include "OggCodecState.h"
+#include "OpusParser.h"
+#include "VideoUtils.h"
+
+using mp4_demuxer::ByteReader;
+
+namespace mozilla
+{
+
+#define OGG_FLAC_METADATA_TYPE_STREAMINFO 0x7F
+#define FLAC_STREAMINFO_SIZE   34
+
+#define BITMASK(x) ((1ULL << x)-1)
+
+enum
+{
+  FLAC_METADATA_TYPE_STREAMINFO = 0,
+  FLAC_METADATA_TYPE_PADDING,
+  FLAC_METADATA_TYPE_APPLICATION,
+  FLAC_METADATA_TYPE_SEEKTABLE,
+  FLAC_METADATA_TYPE_VORBIS_COMMENT,
+  FLAC_METADATA_TYPE_CUESHEET,
+  FLAC_METADATA_TYPE_PICTURE,
+  FLAC_METADATA_TYPE_INVALID = 127
+};
+
+FlacFrameParser::FlacFrameParser()
+  : mMinBlockSize(0)
+  , mMaxBlockSize(0)
+  , mMinFrameSize(0)
+  , mMaxFrameSize(0)
+  , mNumFrames(0)
+  , mFullMetadata(false)
+  , mPacketCount(0)
+{
+}
+
+FlacFrameParser::~FlacFrameParser()
+{
+}
+
+uint32_t
+FlacFrameParser::HeaderBlockLength(const uint8_t* aPacket) const
+{
+  uint32_t extra = 4;
+  if (aPacket[0] == 'f') {
+    // This must be the first block read, which contains the fLaC signature.
+    aPacket += 4;
+    extra += 4;
+  }
+  return (BigEndian::readUint32(aPacket) & BITMASK(24)) + extra;
+}
+
+bool
+FlacFrameParser::DecodeHeaderBlock(const uint8_t* aPacket, size_t aLength)
+{
+  if (aLength < 4 || aPacket[0] == 0xff) {
+    // Not a header block.
+    return false;
+  }
+  ByteReader br(aPacket, aLength);
+
+  mPacketCount++;
+
+  if (aPacket[0] == 'f') {
+    if (mPacketCount != 1 || memcmp(br.Read(4), "fLaC", 4) ||
+        br.Remaining() != FLAC_STREAMINFO_SIZE + 4) {
+      return false;
+    }
+    aPacket += 4;
+    aLength -= 4;
+  }
+  uint8_t blockHeader = br.ReadU8();
+  // blockType is a misnomer as it could indicate here either a packet type
+  // should it points to the start of a Flac in Ogg metadata, or an actual
+  // block type as per the flac specification.
+  uint32_t blockType = blockHeader & 0x7f;
+  bool lastBlock = blockHeader & 0x80;
+
+  if (blockType == OGG_FLAC_METADATA_TYPE_STREAMINFO) {
+    if (mPacketCount != 1 || memcmp(br.Read(4), "FLAC", 4) ||
+        br.Remaining() != FLAC_STREAMINFO_SIZE + 12) {
+      return false;
+    }
+    uint32_t major = br.ReadU8();
+    if (major != 1) {
+      // unsupported version;
+      return false;
+    }
+    br.ReadU8(); // minor version
+    mNumHeaders = Some(uint32_t(br.ReadU16()));
+    br.Read(4); // fLaC
+    blockType = br.ReadU8() & BITMASK(7);
+    // First METADATA_BLOCK_STREAMINFO
+    if (blockType != FLAC_METADATA_TYPE_STREAMINFO) {
+      // First block must be a stream info.
+      return false;
+    }
+  }
+
+  uint32_t blockDataSize = br.ReadU24();
+  const uint8_t* blockDataStart = br.Peek(blockDataSize);
+  if (!blockDataStart) {
+    // Incomplete block.
+    return false;
+  }
+
+  switch (blockType) {
+    case FLAC_METADATA_TYPE_STREAMINFO:
+    {
+      if (mPacketCount != 1 || blockDataSize != FLAC_STREAMINFO_SIZE) {
+        // STREAMINFO must be the first metadata block found, and its size
+        // is constant.
+        return false;
+      }
+
+      mMinBlockSize = br.ReadU16();
+      mMaxBlockSize = br.ReadU16();
+      mMinFrameSize = br.ReadU24();
+      mMaxFrameSize = br.ReadU24();
+
+      uint64_t blob = br.ReadU64();
+      uint32_t sampleRate = (blob >> 44) & BITMASK(20);
+      if (!sampleRate) {
+        return false;
+      }
+      uint32_t numChannels = ((blob >> 41) & BITMASK(3)) + 1;
+      if (numChannels > FLAC_MAX_CHANNELS) {
+        return false;
+      }
+      uint32_t bps = ((blob >> 36) & BITMASK(5)) + 1;
+      if (bps > 24) {
+        return false;
+      }
+      mNumFrames = blob & BITMASK(36);
+
+      mInfo.mMimeType = "audio/flac";
+      mInfo.mRate = sampleRate;
+      mInfo.mChannels = numChannels;
+      mInfo.mBitDepth = bps;
+      mInfo.mCodecSpecificConfig->AppendElements(blockDataStart, blockDataSize);
+      CheckedInt64 duration =
+        SaferMultDiv(mNumFrames, USECS_PER_S, sampleRate);
+      mInfo.mDuration = duration.isValid() ? duration.value() : 0;
+      mParser = new OpusParser;
+      break;
+    }
+    case FLAC_METADATA_TYPE_VORBIS_COMMENT:
+    {
+      if (!mParser) {
+        // We must have seen a valid streaminfo first.
+        return false;
+      }
+      nsTArray<uint8_t> comments(blockDataSize + 8);
+      comments.AppendElements("OpusTags", 8);
+      comments.AppendElements(blockDataStart, blockDataSize);
+      if (!mParser->DecodeTags(comments.Elements(), comments.Length())) {
+        return false;
+      }
+      break;
+    }
+    default:
+      break;
+  }
+
+  if (mNumHeaders && mPacketCount > mNumHeaders.ref() + 1) {
+    // Received too many header block. assuming invalid.
+    return false;
+  }
+
+  if (lastBlock || (mNumHeaders && mNumHeaders.ref() + 1 == mPacketCount)) {
+    mFullMetadata = true;
+  }
+
+  return true;
+}
+
+int64_t
+FlacFrameParser::BlockDuration(const uint8_t* aPacket, size_t aLength) const
+{
+  if (!mInfo.IsValid()) {
+    return -1;
+  }
+  if (mMinBlockSize == mMaxBlockSize) {
+    // block size is fixed, use this instead of looking at the frame header.
+    return mMinBlockSize;
+  }
+  // TODO
+  return 0;
+}
+
+bool
+FlacFrameParser::IsHeaderBlock(const uint8_t* aPacket, size_t aLength) const
+{
+  // Ogg Flac header
+  // The one-byte packet type 0x7F
+  // The four-byte ASCII signature "FLAC", i.e. 0x46, 0x4C, 0x41, 0x43
+
+  // Flac header:
+  // "fLaC", the FLAC stream marker in ASCII, meaning byte 0 of the stream is 0x66, followed by 0x4C 0x61 0x43
+
+  // If we detect either a ogg or plain flac header, then it must be valid.
+  if (aLength < 4 || aPacket[0] == 0xff) {
+    // A header is at least 4 bytes.
+    return false;
+  }
+  if (aPacket[0] == 0x7f) {
+    // Ogg packet
+    ByteReader br(aPacket + 1, aLength - 1);
+    const uint8_t* signature = br.Read(4);
+    return signature && !memcmp(signature, "FLAC", 4);
+  }
+  ByteReader br(aPacket, aLength - 1);
+  const uint8_t* signature = br.Read(4);
+  if (signature && !memcmp(signature, "fLaC", 4)) {
+    // Flac start header, must have STREAMINFO as first metadata block;
+    if (!br.CanRead8()) {
+      return false;
+    }
+    uint32_t blockType = br.ReadU8() & 0x7f;
+    return blockType == FLAC_METADATA_TYPE_STREAMINFO;
+  }
+  char type = aPacket[0] & 0x7f;
+  return type >= 1 && type <= 6;
+}
+
+MetadataTags*
+FlacFrameParser::GetTags() const
+{
+  MetadataTags* tags;
+
+  tags = new MetadataTags;
+  for (uint32_t i = 0; i < mParser->mTags.Length(); i++) {
+    OggCodecState::AddVorbisComment(tags,
+                                    mParser->mTags[i].Data(),
+                                    mParser->mTags[i].Length());
+  }
+
+  return tags;
+}
+
+} // namespace mozilla
diff --git a/dom/media/flac/FlacFrameParser.h b/dom/media/flac/FlacFrameParser.h
new file mode 100644
index 0000000000..aa1a6e15b8
--- /dev/null
+++ b/dom/media/flac/FlacFrameParser.h
@@ -0,0 +1,64 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+#ifndef FLAC_FRAME_PARSER_H_
+#define FLAC_FRAME_PARSER_H_
+
+#include "mozilla/Maybe.h"
+#include "nsAutoPtr.h"
+#include "MediaDecoder.h" // For MetadataTags
+#include "MediaInfo.h"
+#include "MediaResource.h"
+
+namespace mozilla
+{
+
+class OpusParser;
+
+// Decode a Flac Metadata block contained in either a ogg packet
+// (https://xiph.org/flac/ogg_mapping.html) or in flac container
+// (https://xiph.org/flac/format.html#frame_header)
+
+class FlacFrameParser
+{
+public:
+  FlacFrameParser();
+  ~FlacFrameParser();
+
+  bool IsHeaderBlock(const uint8_t* aPacket, size_t aLength) const;
+  // Return the length of the block header (METADATA_BLOCK_HEADER+
+  // METADATA_BLOCK_DATA), aPacket must point to at least 4
+  // bytes and to a valid block header start (as determined by IsHeaderBlock).
+  uint32_t HeaderBlockLength(const uint8_t* aPacket) const;
+  bool DecodeHeaderBlock(const uint8_t* aPacket, size_t aLength);
+  bool HasFullMetadata() const { return mFullMetadata; }
+  // Return the duration in frames found in the block. -1 if error
+  // such as invalid packet.
+  int64_t BlockDuration(const uint8_t* aPacket, size_t aLength) const;
+
+  // Return a hash table with tag metadata.
+  MetadataTags* GetTags() const;
+
+  AudioInfo mInfo;
+
+private:
+  bool ReconstructFlacGranulepos(void);
+  Maybe<uint32_t> mNumHeaders;
+  uint32_t mMinBlockSize;
+  uint32_t mMaxBlockSize;
+  uint32_t mMinFrameSize;
+  uint32_t mMaxFrameSize;
+  uint64_t mNumFrames;
+  bool mFullMetadata;
+  uint32_t mPacketCount;
+
+  // Used to decode the vorbis comment metadata.
+  nsAutoPtr<OpusParser> mParser;
+};
+
+}
+
+#endif // FLAC_FRAME_PARSER_H_
diff --git a/dom/media/flac/moz.build b/dom/media/flac/moz.build
new file mode 100644
index 0000000000..6933ded1f9
--- /dev/null
+++ b/dom/media/flac/moz.build
@@ -0,0 +1,24 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+EXPORTS += [
+    'FlacDecoder.h',
+    'FlacDemuxer.h',
+    'FlacFrameParser.h',
+]
+
+UNIFIED_SOURCES += [
+    'FlacDecoder.cpp',
+    'FlacDemuxer.cpp',
+    'FlacFrameParser.cpp',
+]
+
+CXXFLAGS += CONFIG['MOZ_LIBVPX_CFLAGS']
+
+FINAL_LIBRARY = 'xul'
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']