/* -*- 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