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Diffstat (limited to 'dom/media/mp3/MP3Demuxer.cpp')
| -rw-r--r-- | dom/media/mp3/MP3Demuxer.cpp | 1340 |
1 files changed, 1340 insertions, 0 deletions
diff --git a/dom/media/mp3/MP3Demuxer.cpp b/dom/media/mp3/MP3Demuxer.cpp new file mode 100644 index 000000000..5a98cabfe --- /dev/null +++ b/dom/media/mp3/MP3Demuxer.cpp @@ -0,0 +1,1340 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim:set ts=2 sw=2 sts=2 et cindent: */ +/* 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 "MP3Demuxer.h" + +#include <inttypes.h> +#include <algorithm> + +#include "mozilla/Assertions.h" +#include "mozilla/EndianUtils.h" +#include "nsAutoPtr.h" +#include "VideoUtils.h" +#include "TimeUnits.h" +#include "prenv.h" + +#ifdef PR_LOGGING +extern mozilla::LazyLogModule gMediaDemuxerLog; +#define MP3LOG(msg, ...) \ + MOZ_LOG(gMediaDemuxerLog, LogLevel::Debug, ("MP3Demuxer " msg, ##__VA_ARGS__)) +#define MP3LOGV(msg, ...) \ + MOZ_LOG(gMediaDemuxerLog, LogLevel::Verbose, ("MP3Demuxer " msg, ##__VA_ARGS__)) +#else +#define MP3LOG(msg, ...) +#define MP3LOGV(msg, ...) +#endif + +using mozilla::media::TimeUnit; +using mozilla::media::TimeInterval; +using mozilla::media::TimeIntervals; +using mp4_demuxer::ByteReader; + +namespace mozilla { + +// MP3Demuxer + +MP3Demuxer::MP3Demuxer(MediaResource* aSource) + : mSource(aSource) +{} + +bool +MP3Demuxer::InitInternal() { + if (!mTrackDemuxer) { + mTrackDemuxer = new MP3TrackDemuxer(mSource); + } + return mTrackDemuxer->Init(); +} + +RefPtr<MP3Demuxer::InitPromise> +MP3Demuxer::Init() { + if (!InitInternal()) { + MP3LOG("MP3Demuxer::Init() failure: waiting for data"); + + return InitPromise::CreateAndReject( + NS_ERROR_DOM_MEDIA_METADATA_ERR, __func__); + } + + MP3LOG("MP3Demuxer::Init() successful"); + return InitPromise::CreateAndResolve(NS_OK, __func__); +} + +bool +MP3Demuxer::HasTrackType(TrackInfo::TrackType aType) const { + return aType == TrackInfo::kAudioTrack; +} + +uint32_t +MP3Demuxer::GetNumberTracks(TrackInfo::TrackType aType) const { + return aType == TrackInfo::kAudioTrack ? 1u : 0u; +} + +already_AddRefed<MediaTrackDemuxer> +MP3Demuxer::GetTrackDemuxer(TrackInfo::TrackType aType, uint32_t aTrackNumber) { + if (!mTrackDemuxer) { + return nullptr; + } + return RefPtr<MP3TrackDemuxer>(mTrackDemuxer).forget(); +} + +bool +MP3Demuxer::IsSeekable() const { + return true; +} + +void +MP3Demuxer::NotifyDataArrived() { + // TODO: bug 1169485. + NS_WARNING("Unimplemented function NotifyDataArrived"); + MP3LOGV("NotifyDataArrived()"); +} + +void +MP3Demuxer::NotifyDataRemoved() { + // TODO: bug 1169485. + NS_WARNING("Unimplemented function NotifyDataRemoved"); + MP3LOGV("NotifyDataRemoved()"); +} + + +// MP3TrackDemuxer + +MP3TrackDemuxer::MP3TrackDemuxer(MediaResource* aSource) + : mSource(aSource) + , mOffset(0) + , mFirstFrameOffset(0) + , mNumParsedFrames(0) + , mFrameIndex(0) + , mTotalFrameLen(0) + , mSamplesPerFrame(0) + , mSamplesPerSecond(0) + , mChannels(0) +{ + Reset(); +} + +bool +MP3TrackDemuxer::Init() { + Reset(); + FastSeek(TimeUnit()); + // Read the first frame to fetch sample rate and other meta data. + RefPtr<MediaRawData> frame(GetNextFrame(FindFirstFrame())); + + MP3LOG("Init StreamLength()=%" PRId64 " first-frame-found=%d", + StreamLength(), !!frame); + + if (!frame) { + return false; + } + + // Rewind back to the stream begin to avoid dropping the first frame. + FastSeek(TimeUnit()); + + if (!mInfo) { + mInfo = MakeUnique<AudioInfo>(); + } + + mInfo->mRate = mSamplesPerSecond; + mInfo->mChannels = mChannels; + mInfo->mBitDepth = 16; + mInfo->mMimeType = "audio/mpeg"; + mInfo->mDuration = Duration().ToMicroseconds(); + + MP3LOG("Init mInfo={mRate=%d mChannels=%d mBitDepth=%d mDuration=%" PRId64 "}", + mInfo->mRate, mInfo->mChannels, mInfo->mBitDepth, + mInfo->mDuration); + + return mSamplesPerSecond && mChannels; +} + +media::TimeUnit +MP3TrackDemuxer::SeekPosition() const { + TimeUnit pos = Duration(mFrameIndex); + if (Duration() > TimeUnit()) { + pos = std::min(Duration(), pos); + } + return pos; +} + +const FrameParser::Frame& +MP3TrackDemuxer::LastFrame() const { + return mParser.PrevFrame(); +} + +RefPtr<MediaRawData> +MP3TrackDemuxer::DemuxSample() { + return GetNextFrame(FindNextFrame()); +} + +const ID3Parser::ID3Header& +MP3TrackDemuxer::ID3Header() const { + return mParser.ID3Header(); +} + +const FrameParser::VBRHeader& +MP3TrackDemuxer::VBRInfo() const { + return mParser.VBRInfo(); +} + +UniquePtr<TrackInfo> +MP3TrackDemuxer::GetInfo() const { + return mInfo->Clone(); +} + +RefPtr<MP3TrackDemuxer::SeekPromise> +MP3TrackDemuxer::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 +MP3TrackDemuxer::FastSeek(const TimeUnit& aTime) { + MP3LOG("FastSeek(%" PRId64 ") avgFrameLen=%f mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mOffset=%" PRIu64, + aTime.ToMicroseconds(), AverageFrameLength(), mNumParsedFrames, + mFrameIndex, mOffset); + + const auto& vbr = mParser.VBRInfo(); + if (!aTime.ToMicroseconds()) { + // Quick seek to the beginning of the stream. + mFrameIndex = 0; + } else if (vbr.IsTOCPresent() && Duration().ToMicroseconds() > 0) { + // Use TOC for more precise seeking. + const float durationFrac = static_cast<float>(aTime.ToMicroseconds()) / + Duration().ToMicroseconds(); + mFrameIndex = FrameIndexFromOffset(vbr.Offset(durationFrac)); + } else if (AverageFrameLength() > 0) { + mFrameIndex = FrameIndexFromTime(aTime); + } + + mOffset = OffsetFromFrameIndex(mFrameIndex); + + if (mOffset > mFirstFrameOffset && StreamLength() > 0) { + mOffset = std::min(StreamLength() - 1, mOffset); + } + + mParser.EndFrameSession(); + + MP3LOG("FastSeek End TOC=%d avgFrameLen=%f mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mFirstFrameOffset=%llu mOffset=%" PRIu64 + " SL=%llu NumBytes=%u", + vbr.IsTOCPresent(), AverageFrameLength(), mNumParsedFrames, mFrameIndex, + mFirstFrameOffset, mOffset, StreamLength(), vbr.NumBytes().valueOr(0)); + + return Duration(mFrameIndex); +} + +TimeUnit +MP3TrackDemuxer::ScanUntil(const TimeUnit& aTime) { + MP3LOG("ScanUntil(%" PRId64 ") avgFrameLen=%f mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mOffset=%" PRIu64, + aTime.ToMicroseconds(), AverageFrameLength(), mNumParsedFrames, + mFrameIndex, mOffset); + + if (!aTime.ToMicroseconds()) { + return FastSeek(aTime); + } + + if (Duration(mFrameIndex) > aTime) { + FastSeek(aTime); + } + + if (Duration(mFrameIndex + 1) > aTime) { + return SeekPosition(); + } + + MediaByteRange nextRange = FindNextFrame(); + while (SkipNextFrame(nextRange) && Duration(mFrameIndex + 1) < aTime) { + nextRange = FindNextFrame(); + MP3LOGV("ScanUntil* avgFrameLen=%f mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mOffset=%" PRIu64 " Duration=%" PRId64, + AverageFrameLength(), mNumParsedFrames, + mFrameIndex, mOffset, Duration(mFrameIndex + 1).ToMicroseconds()); + } + + MP3LOG("ScanUntil End avgFrameLen=%f mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mOffset=%" PRIu64, + AverageFrameLength(), mNumParsedFrames, mFrameIndex, mOffset); + + return SeekPosition(); +} + +RefPtr<MP3TrackDemuxer::SamplesPromise> +MP3TrackDemuxer::GetSamples(int32_t aNumSamples) { + MP3LOGV("GetSamples(%d) Begin mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d " + "mSamplesPerSecond=%d mChannels=%d", + aNumSamples, mOffset, mNumParsedFrames, mFrameIndex, mTotalFrameLen, + mSamplesPerFrame, mSamplesPerSecond, mChannels); + + 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); + } + + MP3LOGV("GetSamples() End mSamples.Size()=%d aNumSamples=%d mOffset=%" PRIu64 + " mNumParsedFrames=%" PRIu64 " mFrameIndex=%" PRId64 + " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d mSamplesPerSecond=%d " + "mChannels=%d", + frames->mSamples.Length(), aNumSamples, mOffset, mNumParsedFrames, + mFrameIndex, mTotalFrameLen, mSamplesPerFrame, mSamplesPerSecond, + mChannels); + + if (frames->mSamples.IsEmpty()) { + return SamplesPromise::CreateAndReject( + NS_ERROR_DOM_MEDIA_END_OF_STREAM, __func__); + } + return SamplesPromise::CreateAndResolve(frames, __func__); +} + +void +MP3TrackDemuxer::Reset() { + MP3LOG("Reset()"); + + FastSeek(TimeUnit()); + mParser.Reset(); +} + +RefPtr<MP3TrackDemuxer::SkipAccessPointPromise> +MP3TrackDemuxer::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 +MP3TrackDemuxer::GetResourceOffset() const { + return mOffset; +} + +TimeIntervals +MP3TrackDemuxer::GetBuffered() { + AutoPinned<MediaResource> stream(mSource.GetResource()); + TimeIntervals buffered; + + if (Duration() > TimeUnit() && stream->IsDataCachedToEndOfResource(0)) { + // Special case completely cached files. This also handles local files. + buffered += TimeInterval(TimeUnit(), Duration()); + MP3LOGV("buffered = [[%" PRId64 ", %" PRId64 "]]", + TimeUnit().ToMicroseconds(), Duration().ToMicroseconds()); + return buffered; + } + + MediaByteRangeSet ranges; + nsresult rv = stream->GetCachedRanges(ranges); + NS_ENSURE_SUCCESS(rv, buffered); + + for (const auto& range: ranges) { + if (range.IsEmpty()) { + continue; + } + TimeUnit start = Duration(FrameIndexFromOffset(range.mStart)); + TimeUnit end = Duration(FrameIndexFromOffset(range.mEnd)); + MP3LOGV("buffered += [%" PRId64 ", %" PRId64 "]", + start.ToMicroseconds(), end.ToMicroseconds()); + buffered += TimeInterval(start, end); + } + + return buffered; +} + +int64_t +MP3TrackDemuxer::StreamLength() const { + return mSource.GetLength(); +} + +TimeUnit +MP3TrackDemuxer::Duration() const { + if (!mNumParsedFrames) { + return TimeUnit::FromMicroseconds(-1); + } + + int64_t numFrames = 0; + const auto numAudioFrames = mParser.VBRInfo().NumAudioFrames(); + if (mParser.VBRInfo().IsValid() && numAudioFrames.valueOr(0) + 1 > 1) { + // VBR headers don't include the VBR header frame. + numFrames = numAudioFrames.value() + 1; + } else { + const int64_t streamLen = StreamLength(); + if (streamLen < 0) { + // Unknown length, we can't estimate duration. + return TimeUnit::FromMicroseconds(-1); + } + if (AverageFrameLength() > 0) { + numFrames = (streamLen - mFirstFrameOffset) / AverageFrameLength(); + } + } + return Duration(numFrames); +} + +TimeUnit +MP3TrackDemuxer::Duration(int64_t aNumFrames) const { + if (!mSamplesPerSecond) { + return TimeUnit::FromMicroseconds(-1); + } + + const double usPerFrame = USECS_PER_S * mSamplesPerFrame / mSamplesPerSecond; + return TimeUnit::FromMicroseconds(aNumFrames * usPerFrame); +} + +MediaByteRange +MP3TrackDemuxer::FindFirstFrame() { + static const int MIN_SUCCESSIVE_FRAMES = 4; + + MediaByteRange candidateFrame = FindNextFrame(); + int numSuccFrames = candidateFrame.Length() > 0; + MediaByteRange currentFrame = candidateFrame; + MP3LOGV("FindFirst() first candidate frame: mOffset=%" PRIu64 " Length()=%" PRIu64, + candidateFrame.mStart, candidateFrame.Length()); + + while (candidateFrame.Length() && numSuccFrames < MIN_SUCCESSIVE_FRAMES) { + mParser.EndFrameSession(); + mOffset = currentFrame.mEnd; + const MediaByteRange prevFrame = currentFrame; + + // FindNextFrame() here will only return frames consistent with our candidate frame. + currentFrame = FindNextFrame(); + numSuccFrames += currentFrame.Length() > 0; + // Multiple successive false positives, which wouldn't be caught by the consistency + // checks alone, can be detected by wrong alignment (non-zero gap between frames). + const int64_t frameSeparation = currentFrame.mStart - prevFrame.mEnd; + + if (!currentFrame.Length() || frameSeparation != 0) { + MP3LOGV("FindFirst() not enough successive frames detected, " + "rejecting candidate frame: successiveFrames=%d, last Length()=%" PRIu64 + ", last frameSeparation=%" PRId64, numSuccFrames, currentFrame.Length(), + frameSeparation); + + mParser.ResetFrameData(); + mOffset = candidateFrame.mStart + 1; + candidateFrame = FindNextFrame(); + numSuccFrames = candidateFrame.Length() > 0; + currentFrame = candidateFrame; + MP3LOGV("FindFirst() new candidate frame: mOffset=%" PRIu64 " Length()=%" PRIu64, + candidateFrame.mStart, candidateFrame.Length()); + } + } + + if (numSuccFrames >= MIN_SUCCESSIVE_FRAMES) { + MP3LOG("FindFirst() accepting candidate frame: " + "successiveFrames=%d", numSuccFrames); + } else { + MP3LOG("FindFirst() no suitable first frame found"); + } + return candidateFrame; +} + +static bool +VerifyFrameConsistency( + const FrameParser::Frame& aFrame1, const FrameParser::Frame& aFrame2) { + const auto& h1 = aFrame1.Header(); + const auto& h2 = aFrame2.Header(); + + return h1.IsValid() && h2.IsValid() && + h1.Layer() == h2.Layer() && + h1.SlotSize() == h2.SlotSize() && + h1.SamplesPerFrame() == h2.SamplesPerFrame() && + h1.Channels() == h2.Channels() && + h1.SampleRate() == h2.SampleRate() && + h1.RawVersion() == h2.RawVersion() && + h1.RawProtection() == h2.RawProtection(); +} + +MediaByteRange +MP3TrackDemuxer::FindNextFrame() { + static const int BUFFER_SIZE = 64; + static const int MAX_SKIPPED_BYTES = 1024 * BUFFER_SIZE; + + MP3LOGV("FindNext() Begin mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mTotalFrameLen=%" PRIu64 + " mSamplesPerFrame=%d mSamplesPerSecond=%d mChannels=%d", + mOffset, mNumParsedFrames, mFrameIndex, mTotalFrameLen, + mSamplesPerFrame, mSamplesPerSecond, mChannels); + + uint8_t buffer[BUFFER_SIZE]; + int32_t read = 0; + + bool foundFrame = false; + int64_t frameHeaderOffset = 0; + + // Check whether we've found a valid MPEG frame. + while (!foundFrame) { + if ((!mParser.FirstFrame().Length() && + mOffset - mParser.ID3Header().Size() > MAX_SKIPPED_BYTES) || + (read = Read(buffer, mOffset, BUFFER_SIZE)) == 0) { + MP3LOG("FindNext() EOS or exceeded MAX_SKIPPED_BYTES without a frame"); + // This is not a valid MPEG audio stream or we've reached EOS, give up. + break; + } + + ByteReader reader(buffer, read); + uint32_t bytesToSkip = 0; + foundFrame = mParser.Parse(&reader, &bytesToSkip); + frameHeaderOffset = mOffset + reader.Offset() - FrameParser::FrameHeader::SIZE; + + // If we've found neither an MPEG frame header nor an ID3v2 tag, + // the reader shouldn't have any bytes remaining. + MOZ_ASSERT(foundFrame || bytesToSkip || !reader.Remaining()); + + if (foundFrame && mParser.FirstFrame().Length() && + !VerifyFrameConsistency(mParser.FirstFrame(), mParser.CurrentFrame())) { + // We've likely hit a false-positive, ignore it and proceed with the + // search for the next valid frame. + foundFrame = false; + mOffset = frameHeaderOffset + 1; + mParser.EndFrameSession(); + } else { + // Advance mOffset by the amount of bytes read and if necessary, + // skip an ID3v2 tag which stretches beyond the current buffer. + NS_ENSURE_TRUE(mOffset + read + bytesToSkip > mOffset, + MediaByteRange(0, 0)); + mOffset += read + bytesToSkip; + } + } + + if (!foundFrame || !mParser.CurrentFrame().Length()) { + MP3LOG("FindNext() Exit foundFrame=%d mParser.CurrentFrame().Length()=%d ", + foundFrame, mParser.CurrentFrame().Length()); + return { 0, 0 }; + } + + MP3LOGV("FindNext() End mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " frameHeaderOffset=%d" + " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d mSamplesPerSecond=%d" + " mChannels=%d", + mOffset, mNumParsedFrames, mFrameIndex, frameHeaderOffset, + mTotalFrameLen, mSamplesPerFrame, mSamplesPerSecond, mChannels); + + return { frameHeaderOffset, frameHeaderOffset + mParser.CurrentFrame().Length() }; +} + +bool +MP3TrackDemuxer::SkipNextFrame(const MediaByteRange& aRange) { + if (!mNumParsedFrames || !aRange.Length()) { + // We can't skip the first frame, since it could contain VBR headers. + RefPtr<MediaRawData> frame(GetNextFrame(aRange)); + return frame; + } + + UpdateState(aRange); + + MP3LOGV("SkipNext() End mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mTotalFrameLen=%" PRIu64 + " mSamplesPerFrame=%d mSamplesPerSecond=%d mChannels=%d", + mOffset, mNumParsedFrames, mFrameIndex, mTotalFrameLen, + mSamplesPerFrame, mSamplesPerSecond, mChannels); + + return true; +} + +already_AddRefed<MediaRawData> +MP3TrackDemuxer::GetNextFrame(const MediaByteRange& aRange) { + MP3LOG("GetNext() Begin({mStart=%" PRId64 " Length()=%" PRId64 "})", + aRange.mStart, aRange.Length()); + if (!aRange.Length()) { + return nullptr; + } + + RefPtr<MediaRawData> frame = new MediaRawData(); + frame->mOffset = aRange.mStart; + + nsAutoPtr<MediaRawDataWriter> frameWriter(frame->CreateWriter()); + if (!frameWriter->SetSize(aRange.Length())) { + MP3LOG("GetNext() Exit failed to allocated media buffer"); + return nullptr; + } + + const uint32_t read = Read(frameWriter->Data(), frame->mOffset, frame->Size()); + + if (read != aRange.Length()) { + MP3LOG("GetNext() Exit read=%u frame->Size()=%u", read, frame->Size()); + return nullptr; + } + + UpdateState(aRange); + + frame->mTime = Duration(mFrameIndex - 1).ToMicroseconds(); + frame->mDuration = Duration(1).ToMicroseconds(); + frame->mTimecode = frame->mTime; + frame->mKeyframe = true; + + MOZ_ASSERT(frame->mTime >= 0); + MOZ_ASSERT(frame->mDuration > 0); + + if (mNumParsedFrames == 1) { + // First frame parsed, let's read VBR info if available. + ByteReader reader(frame->Data(), frame->Size()); + mParser.ParseVBRHeader(&reader); + mFirstFrameOffset = frame->mOffset; + } + + MP3LOGV("GetNext() End mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64 + " mFrameIndex=%" PRId64 " mTotalFrameLen=%" PRIu64 + " mSamplesPerFrame=%d mSamplesPerSecond=%d mChannels=%d", + mOffset, mNumParsedFrames, mFrameIndex, mTotalFrameLen, + mSamplesPerFrame, mSamplesPerSecond, mChannels); + + return frame.forget(); +} + +int64_t +MP3TrackDemuxer::OffsetFromFrameIndex(int64_t aFrameIndex) const { + int64_t offset = 0; + const auto& vbr = mParser.VBRInfo(); + + if (vbr.IsComplete()) { + offset = mFirstFrameOffset + aFrameIndex * vbr.NumBytes().value() / + vbr.NumAudioFrames().value(); + } else if (AverageFrameLength() > 0) { + offset = mFirstFrameOffset + aFrameIndex * AverageFrameLength(); + } + + MP3LOGV("OffsetFromFrameIndex(%" PRId64 ") -> %" PRId64, aFrameIndex, offset); + return std::max<int64_t>(mFirstFrameOffset, offset); +} + +int64_t +MP3TrackDemuxer::FrameIndexFromOffset(int64_t aOffset) const { + int64_t frameIndex = 0; + const auto& vbr = mParser.VBRInfo(); + + if (vbr.IsComplete()) { + frameIndex = static_cast<float>(aOffset - mFirstFrameOffset) / + vbr.NumBytes().value() * vbr.NumAudioFrames().value(); + frameIndex = std::min<int64_t>(vbr.NumAudioFrames().value(), frameIndex); + } else if (AverageFrameLength() > 0) { + frameIndex = (aOffset - mFirstFrameOffset) / AverageFrameLength(); + } + + MP3LOGV("FrameIndexFromOffset(%" PRId64 ") -> %" PRId64, aOffset, frameIndex); + return std::max<int64_t>(0, frameIndex); +} + +int64_t +MP3TrackDemuxer::FrameIndexFromTime(const media::TimeUnit& aTime) const { + int64_t frameIndex = 0; + if (mSamplesPerSecond > 0 && mSamplesPerFrame > 0) { + frameIndex = aTime.ToSeconds() * mSamplesPerSecond / mSamplesPerFrame - 1; + } + + MP3LOGV("FrameIndexFromOffset(%fs) -> %" PRId64, aTime.ToSeconds(), frameIndex); + return std::max<int64_t>(0, frameIndex); +} + +void +MP3TrackDemuxer::UpdateState(const MediaByteRange& aRange) { + // Prevent overflow. + if (mTotalFrameLen + aRange.Length() < mTotalFrameLen) { + // These variables have a linear dependency and are only used to derive the + // average frame length. + mTotalFrameLen /= 2; + mNumParsedFrames /= 2; + } + + // Full frame parsed, move offset to its end. + mOffset = aRange.mEnd; + + mTotalFrameLen += aRange.Length(); + + if (!mSamplesPerFrame) { + mSamplesPerFrame = mParser.CurrentFrame().Header().SamplesPerFrame(); + mSamplesPerSecond = mParser.CurrentFrame().Header().SampleRate(); + mChannels = mParser.CurrentFrame().Header().Channels(); + } + + ++mNumParsedFrames; + ++mFrameIndex; + MOZ_ASSERT(mFrameIndex > 0); + + // Prepare the parser for the next frame parsing session. + mParser.EndFrameSession(); +} + +int32_t +MP3TrackDemuxer::Read(uint8_t* aBuffer, int64_t aOffset, int32_t aSize) { + MP3LOGV("MP3TrackDemuxer::Read(%p %" PRId64 " %d)", aBuffer, aOffset, aSize); + + const int64_t streamLen = StreamLength(); + if (mInfo && streamLen > 0) { + // Prevent blocking reads after successful initialization. + aSize = std::min<int64_t>(aSize, streamLen - aOffset); + } + + uint32_t read = 0; + MP3LOGV("MP3TrackDemuxer::Read -> ReadAt(%d)", aSize); + 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 +MP3TrackDemuxer::AverageFrameLength() const { + if (mNumParsedFrames) { + return static_cast<double>(mTotalFrameLen) / mNumParsedFrames; + } + const auto& vbr = mParser.VBRInfo(); + if (vbr.IsComplete() && vbr.NumAudioFrames().value() + 1) { + return static_cast<double>(vbr.NumBytes().value()) / + (vbr.NumAudioFrames().value() + 1); + } + return 0.0; +} + +// FrameParser + +namespace frame_header { +// FrameHeader mRaw byte offsets. +static const int SYNC1 = 0; +static const int SYNC2_VERSION_LAYER_PROTECTION = 1; +static const int BITRATE_SAMPLERATE_PADDING_PRIVATE = 2; +static const int CHANNELMODE_MODEEXT_COPY_ORIG_EMPH = 3; +} // namespace frame_header + +FrameParser::FrameParser() +{ +} + +void +FrameParser::Reset() { + mID3Parser.Reset(); + mFrame.Reset(); +} + +void +FrameParser::ResetFrameData() { + mFrame.Reset(); + mFirstFrame.Reset(); + mPrevFrame.Reset(); +} + +void +FrameParser::EndFrameSession() { + if (!mID3Parser.Header().IsValid()) { + // Reset ID3 tags only if we have not parsed a valid ID3 header yet. + mID3Parser.Reset(); + } + mPrevFrame = mFrame; + mFrame.Reset(); +} + +const FrameParser::Frame& +FrameParser::CurrentFrame() const { + return mFrame; +} + +const FrameParser::Frame& +FrameParser::PrevFrame() const { + return mPrevFrame; +} + +const FrameParser::Frame& +FrameParser::FirstFrame() const { + return mFirstFrame; +} + +const ID3Parser::ID3Header& +FrameParser::ID3Header() const { + return mID3Parser.Header(); +} + +const FrameParser::VBRHeader& +FrameParser::VBRInfo() const { + return mVBRHeader; +} + +bool +FrameParser::Parse(ByteReader* aReader, uint32_t* aBytesToSkip) { + MOZ_ASSERT(aReader && aBytesToSkip); + *aBytesToSkip = 0; + + if (!mID3Parser.Header().Size() && !mFirstFrame.Length()) { + // No MP3 frames have been parsed yet, look for ID3v2 headers at file begin. + // ID3v1 tags may only be at file end. + // TODO: should we try to read ID3 tags at end of file/mid-stream, too? + const size_t prevReaderOffset = aReader->Offset(); + const uint32_t tagSize = mID3Parser.Parse(aReader); + if (tagSize) { + // ID3 tag found, skip past it. + const uint32_t skipSize = tagSize - ID3Parser::ID3Header::SIZE; + + if (skipSize > aReader->Remaining()) { + // Skipping across the ID3v2 tag would take us past the end of the buffer, therefore we + // return immediately and let the calling function handle skipping the rest of the tag. + MP3LOGV("ID3v2 tag detected, size=%d," + " needing to skip %d bytes past the current buffer", + tagSize, skipSize - aReader->Remaining()); + *aBytesToSkip = skipSize - aReader->Remaining(); + return false; + } + MP3LOGV("ID3v2 tag detected, size=%d", tagSize); + aReader->Read(skipSize); + } else { + // No ID3v2 tag found, rewinding reader in order to search for a MPEG frame header. + aReader->Seek(prevReaderOffset); + } + } + + while (aReader->CanRead8() && !mFrame.ParseNext(aReader->ReadU8())) { } + + if (mFrame.Length()) { + // MP3 frame found. + if (!mFirstFrame.Length()) { + mFirstFrame = mFrame; + } + // Indicate success. + return true; + } + return false; +} + +// FrameParser::Header + +FrameParser::FrameHeader::FrameHeader() +{ + Reset(); +} + +uint8_t +FrameParser::FrameHeader::Sync1() const { + return mRaw[frame_header::SYNC1]; +} + +uint8_t +FrameParser::FrameHeader::Sync2() const { + return 0x7 & mRaw[frame_header::SYNC2_VERSION_LAYER_PROTECTION] >> 5; +} + +uint8_t +FrameParser::FrameHeader::RawVersion() const { + return 0x3 & mRaw[frame_header::SYNC2_VERSION_LAYER_PROTECTION] >> 3; +} + +uint8_t +FrameParser::FrameHeader::RawLayer() const { + return 0x3 & mRaw[frame_header::SYNC2_VERSION_LAYER_PROTECTION] >> 1; +} + +uint8_t +FrameParser::FrameHeader::RawProtection() const { + return 0x1 & mRaw[frame_header::SYNC2_VERSION_LAYER_PROTECTION] >> 6; +} + +uint8_t +FrameParser::FrameHeader::RawBitrate() const { + return 0xF & mRaw[frame_header::BITRATE_SAMPLERATE_PADDING_PRIVATE] >> 4; +} + +uint8_t +FrameParser::FrameHeader::RawSampleRate() const { + return 0x3 & mRaw[frame_header::BITRATE_SAMPLERATE_PADDING_PRIVATE] >> 2; +} + +uint8_t +FrameParser::FrameHeader::Padding() const { + return 0x1 & mRaw[frame_header::BITRATE_SAMPLERATE_PADDING_PRIVATE] >> 1; +} + +uint8_t +FrameParser::FrameHeader::Private() const { + return 0x1 & mRaw[frame_header::BITRATE_SAMPLERATE_PADDING_PRIVATE]; +} + +uint8_t +FrameParser::FrameHeader::RawChannelMode() const { + return 0x3 & mRaw[frame_header::CHANNELMODE_MODEEXT_COPY_ORIG_EMPH] >> 6; +} + +int32_t +FrameParser::FrameHeader::Layer() const { + static const uint8_t LAYERS[4] = { 0, 3, 2, 1 }; + + return LAYERS[RawLayer()]; +} + +int32_t +FrameParser::FrameHeader::SampleRate() const { + // Sample rates - use [version][srate] + static const uint16_t SAMPLE_RATE[4][4] = { + { 11025, 12000, 8000, 0 }, // MPEG 2.5 + { 0, 0, 0, 0 }, // Reserved + { 22050, 24000, 16000, 0 }, // MPEG 2 + { 44100, 48000, 32000, 0 } // MPEG 1 + }; + + return SAMPLE_RATE[RawVersion()][RawSampleRate()]; +} + +int32_t +FrameParser::FrameHeader::Channels() const { + // 3 is single channel (mono), any other value is some variant of dual + // channel. + return RawChannelMode() == 3 ? 1 : 2; +} + +int32_t +FrameParser::FrameHeader::SamplesPerFrame() const { + // Samples per frame - use [version][layer] + static const uint16_t FRAME_SAMPLE[4][4] = { + // Layer 3 2 1 Version + { 0, 576, 1152, 384 }, // 2.5 + { 0, 0, 0, 0 }, // Reserved + { 0, 576, 1152, 384 }, // 2 + { 0, 1152, 1152, 384 } // 1 + }; + + return FRAME_SAMPLE[RawVersion()][RawLayer()]; +} + +int32_t +FrameParser::FrameHeader::Bitrate() const { + // Bitrates - use [version][layer][bitrate] + static const uint16_t BITRATE[4][4][16] = { + { // Version 2.5 + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, // Reserved + { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 }, // Layer 3 + { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 }, // Layer 2 + { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 } // Layer 1 + }, + { // Reserved + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, // Invalid + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, // Invalid + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, // Invalid + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } // Invalid + }, + { // Version 2 + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, // Reserved + { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 }, // Layer 3 + { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 }, // Layer 2 + { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 } // Layer 1 + }, + { // Version 1 + { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, // Reserved + { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0 }, // Layer 3 + { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0 }, // Layer 2 + { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0 }, // Layer 1 + } + }; + + return 1000 * BITRATE[RawVersion()][RawLayer()][RawBitrate()]; +} + +int32_t +FrameParser::FrameHeader::SlotSize() const { + // Slot size (MPEG unit of measurement) - use [layer] + static const uint8_t SLOT_SIZE[4] = { 0, 1, 1, 4 }; // Rsvd, 3, 2, 1 + + return SLOT_SIZE[RawLayer()]; +} + +bool +FrameParser::FrameHeader::ParseNext(uint8_t c) { + if (!Update(c)) { + Reset(); + if (!Update(c)) { + Reset(); + } + } + return IsValid(); +} + +bool +FrameParser::FrameHeader::IsValid(int aPos) const { + if (aPos >= SIZE) { + return true; + } + if (aPos == frame_header::SYNC1) { + return Sync1() == 0xFF; + } + if (aPos == frame_header::SYNC2_VERSION_LAYER_PROTECTION) { + return Sync2() == 7 && + RawVersion() != 1 && + Layer() == 3; + } + if (aPos == frame_header::BITRATE_SAMPLERATE_PADDING_PRIVATE) { + return RawBitrate() != 0xF && RawBitrate() != 0 && + RawSampleRate() != 3; + } + return true; +} + +bool +FrameParser::FrameHeader::IsValid() const { + return mPos >= SIZE; +} + +void +FrameParser::FrameHeader::Reset() { + mPos = 0; +} + +bool +FrameParser::FrameHeader::Update(uint8_t c) { + if (mPos < SIZE) { + mRaw[mPos] = c; + } + return IsValid(mPos++); +} + +// FrameParser::VBRHeader + +namespace vbr_header { +static const char* TYPE_STR[3] = {"NONE", "XING", "VBRI"}; +static const uint32_t TOC_SIZE = 100; +} // namespace vbr_header + +FrameParser::VBRHeader::VBRHeader() + : mType(NONE) +{ +} + +FrameParser::VBRHeader::VBRHeaderType +FrameParser::VBRHeader::Type() const { + return mType; +} + +const Maybe<uint32_t>& +FrameParser::VBRHeader::NumAudioFrames() const { + return mNumAudioFrames; +} + +const Maybe<uint32_t>& +FrameParser::VBRHeader::NumBytes() const { + return mNumBytes; +} + +const Maybe<uint32_t>& +FrameParser::VBRHeader::Scale() const { + return mScale; +} + +bool +FrameParser::VBRHeader::IsTOCPresent() const { + return mTOC.size() == vbr_header::TOC_SIZE; +} + +bool +FrameParser::VBRHeader::IsValid() const { + return mType != NONE; +} + +bool +FrameParser::VBRHeader::IsComplete() const { + return IsValid() && + mNumAudioFrames.valueOr(0) > 0 && + mNumBytes.valueOr(0) > 0 && + // We don't care about the scale for any computations here. + // mScale < 101 && + true; +} + +int64_t +FrameParser::VBRHeader::Offset(float aDurationFac) const { + if (!IsTOCPresent()) { + return -1; + } + + // Constrain the duration percentage to [0, 99]. + const float durationPer = 100.0f * std::min(0.99f, std::max(0.0f, aDurationFac)); + const size_t fullPer = durationPer; + const float rest = durationPer - fullPer; + + MOZ_ASSERT(fullPer < mTOC.size()); + int64_t offset = mTOC.at(fullPer); + + if (rest > 0.0 && fullPer + 1 < mTOC.size()) { + offset += rest * (mTOC.at(fullPer + 1) - offset); + } + + return offset; +} + +bool +FrameParser::VBRHeader::ParseXing(ByteReader* aReader) { + static const uint32_t XING_TAG = BigEndian::readUint32("Xing"); + static const uint32_t INFO_TAG = BigEndian::readUint32("Info"); + + enum Flags { + NUM_FRAMES = 0x01, + NUM_BYTES = 0x02, + TOC = 0x04, + VBR_SCALE = 0x08 + }; + + MOZ_ASSERT(aReader); + const size_t prevReaderOffset = aReader->Offset(); + + // We have to search for the Xing header as its position can change. + while (aReader->CanRead32() && + aReader->PeekU32() != XING_TAG && aReader->PeekU32() != INFO_TAG) { + aReader->Read(1); + } + + if (aReader->CanRead32()) { + // Skip across the VBR header ID tag. + aReader->ReadU32(); + mType = XING; + } + uint32_t flags = 0; + if (aReader->CanRead32()) { + flags = aReader->ReadU32(); + } + if (flags & NUM_FRAMES && aReader->CanRead32()) { + mNumAudioFrames = Some(aReader->ReadU32()); + } + if (flags & NUM_BYTES && aReader->CanRead32()) { + mNumBytes = Some(aReader->ReadU32()); + } + if (flags & TOC && aReader->Remaining() >= vbr_header::TOC_SIZE) { + if (!mNumBytes) { + // We don't have the stream size to calculate offsets, skip the TOC. + aReader->Read(vbr_header::TOC_SIZE); + } else { + mTOC.clear(); + mTOC.reserve(vbr_header::TOC_SIZE); + for (size_t i = 0; i < vbr_header::TOC_SIZE; ++i) { + mTOC.push_back(1.0f / 256.0f * aReader->ReadU8() * mNumBytes.value()); + } + } + } + if (flags & VBR_SCALE && aReader->CanRead32()) { + mScale = Some(aReader->ReadU32()); + } + + aReader->Seek(prevReaderOffset); + return mType == XING; +} + +bool +FrameParser::VBRHeader::ParseVBRI(ByteReader* aReader) { + static const uint32_t TAG = BigEndian::readUint32("VBRI"); + static const uint32_t OFFSET = 32 + FrameParser::FrameHeader::SIZE; + static const uint32_t FRAME_COUNT_OFFSET = OFFSET + 14; + static const uint32_t MIN_FRAME_SIZE = OFFSET + 26; + + MOZ_ASSERT(aReader); + // ParseVBRI assumes that the ByteReader offset points to the beginning of a frame, + // therefore as a simple check, we look for the presence of a frame sync at that position. + MOZ_ASSERT((aReader->PeekU16() & 0xFFE0) == 0xFFE0); + const size_t prevReaderOffset = aReader->Offset(); + + // VBRI have a fixed relative position, so let's check for it there. + if (aReader->Remaining() > MIN_FRAME_SIZE) { + aReader->Seek(prevReaderOffset + OFFSET); + if (aReader->ReadU32() == TAG) { + aReader->Seek(prevReaderOffset + FRAME_COUNT_OFFSET); + mNumAudioFrames = Some(aReader->ReadU32()); + mType = VBRI; + aReader->Seek(prevReaderOffset); + return true; + } + } + aReader->Seek(prevReaderOffset); + return false; +} + +bool +FrameParser::VBRHeader::Parse(ByteReader* aReader) { + const bool rv = ParseVBRI(aReader) || ParseXing(aReader); + if (rv) { + MP3LOG("VBRHeader::Parse found valid VBR/CBR header: type=%s" + " NumAudioFrames=%u NumBytes=%u Scale=%u TOC-size=%u", + vbr_header::TYPE_STR[Type()], NumAudioFrames().valueOr(0), + NumBytes().valueOr(0), Scale().valueOr(0), mTOC.size()); + } + return rv; +} + +// FrameParser::Frame + +void +FrameParser::Frame::Reset() { + mHeader.Reset(); +} + +int32_t +FrameParser::Frame::Length() const { + if (!mHeader.IsValid() || !mHeader.SampleRate()) { + return 0; + } + + const float bitsPerSample = mHeader.SamplesPerFrame() / 8.0f; + const int32_t frameLen = bitsPerSample * mHeader.Bitrate() / + mHeader.SampleRate() + + mHeader.Padding() * mHeader.SlotSize(); + return frameLen; +} + +bool +FrameParser::Frame::ParseNext(uint8_t c) { + return mHeader.ParseNext(c); +} + +const FrameParser::FrameHeader& +FrameParser::Frame::Header() const { + return mHeader; +} + +bool +FrameParser::ParseVBRHeader(ByteReader* aReader) { + return mVBRHeader.Parse(aReader); +} + +// ID3Parser + +// Constants +namespace id3_header { +static const int ID_LEN = 3; +static const int VERSION_LEN = 2; +static const int FLAGS_LEN = 1; +static const int SIZE_LEN = 4; + +static const int ID_END = ID_LEN; +static const int VERSION_END = ID_END + VERSION_LEN; +static const int FLAGS_END = VERSION_END + FLAGS_LEN; +static const int SIZE_END = FLAGS_END + SIZE_LEN; + +static const uint8_t ID[ID_LEN] = {'I', 'D', '3'}; + +static const uint8_t MIN_MAJOR_VER = 2; +static const uint8_t MAX_MAJOR_VER = 4; +} // namespace id3_header + +uint32_t +ID3Parser::Parse(ByteReader* aReader) { + MOZ_ASSERT(aReader); + + while (aReader->CanRead8() && !mHeader.ParseNext(aReader->ReadU8())) { } + + if (mHeader.IsValid()) { + // Header found, return total tag size. + return ID3Header::SIZE + Header().Size() + Header().FooterSize(); + } + return 0; +} + +void +ID3Parser::Reset() { + mHeader.Reset(); +} + +const ID3Parser::ID3Header& +ID3Parser::Header() const { + return mHeader; +} + +// ID3Parser::Header + +ID3Parser::ID3Header::ID3Header() +{ + Reset(); +} + +void +ID3Parser::ID3Header::Reset() { + mSize = 0; + mPos = 0; +} + +uint8_t +ID3Parser::ID3Header::MajorVersion() const { + return mRaw[id3_header::ID_END]; +} + +uint8_t +ID3Parser::ID3Header::MinorVersion() const { + return mRaw[id3_header::ID_END + 1]; +} + +uint8_t +ID3Parser::ID3Header::Flags() const { + return mRaw[id3_header::FLAGS_END - id3_header::FLAGS_LEN]; +} + +uint32_t +ID3Parser::ID3Header::Size() const { + if (!IsValid()) { + return 0; + } + return mSize; +} + +uint8_t +ID3Parser::ID3Header::FooterSize() const { + if (Flags() & (1 << 4)) { + return SIZE; + } + return 0; +} + +bool +ID3Parser::ID3Header::ParseNext(uint8_t c) { + if (!Update(c)) { + Reset(); + if (!Update(c)) { + Reset(); + } + } + return IsValid(); +} + +bool +ID3Parser::ID3Header::IsValid(int aPos) const { + if (aPos >= SIZE) { + return true; + } + const uint8_t c = mRaw[aPos]; + switch (aPos) { + case 0: case 1: case 2: + // Expecting "ID3". + return id3_header::ID[aPos] == c; + case 3: + return MajorVersion() >= id3_header::MIN_MAJOR_VER && + MajorVersion() <= id3_header::MAX_MAJOR_VER; + case 4: + return MinorVersion() < 0xFF; + case 5: + // Validate flags for supported versions, see bug 949036. + return ((0xFF >> MajorVersion()) & c) == 0; + case 6: case 7: case 8: case 9: + return c < 0x80; + } + return true; +} + +bool +ID3Parser::ID3Header::IsValid() const { + return mPos >= SIZE; +} + +bool +ID3Parser::ID3Header::Update(uint8_t c) { + if (mPos >= id3_header::SIZE_END - id3_header::SIZE_LEN && + mPos < id3_header::SIZE_END) { + mSize <<= 7; + mSize |= c; + } + if (mPos < SIZE) { + mRaw[mPos] = c; + } + return IsValid(mPos++); +} + +} // namespace mozilla |