diff options
Diffstat (limited to 'dom/media/flac/FlacDemuxer.cpp')
| -rw-r--r-- | dom/media/flac/FlacDemuxer.cpp | 1074 |
1 files changed, 1074 insertions, 0 deletions
diff --git a/dom/media/flac/FlacDemuxer.cpp b/dom/media/flac/FlacDemuxer.cpp new file mode 100644 index 000000000..7a98edbee --- /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 |