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Diffstat (limited to '')
| -rw-r--r-- | dom/media/webm/WebMDemuxer.cpp | 1324 |
1 files changed, 1324 insertions, 0 deletions
diff --git a/dom/media/webm/WebMDemuxer.cpp b/dom/media/webm/WebMDemuxer.cpp new file mode 100644 index 0000000000..2515a4061d --- /dev/null +++ b/dom/media/webm/WebMDemuxer.cpp @@ -0,0 +1,1324 @@ +/* -*- 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 "nsError.h" +#include "MediaResource.h" +#ifdef MOZ_AV1 +# include "AOMDecoder.h" +#endif +#include "OpusDecoder.h" +#include "VPXDecoder.h" +#include "WebMDemuxer.h" +#include "WebMBufferedParser.h" +#include "gfx2DGlue.h" +#include "gfxUtils.h" +#include "mozilla/EndianUtils.h" +#include "mozilla/SharedThreadPool.h" +#include "MediaDataDemuxer.h" +#include "nsAutoRef.h" +#include "NesteggPacketHolder.h" +#include "XiphExtradata.h" +#include "prprf.h" // leaving it for PR_vsnprintf() +#include "mozilla/IntegerPrintfMacros.h" +#include "mozilla/Sprintf.h" +#include "VideoUtils.h" + +#include <algorithm> +#include <numeric> +#include <stdint.h> + +#define WEBM_DEBUG(arg, ...) \ + DDMOZ_LOG(gMediaDemuxerLog, mozilla::LogLevel::Debug, "::%s: " arg, \ + __func__, ##__VA_ARGS__) +extern mozilla::LazyLogModule gMediaDemuxerLog; + +namespace mozilla { + +using namespace gfx; +using media::TimeUnit; + +LazyLogModule gNesteggLog("Nestegg"); + +// How far ahead will we look when searching future keyframe. In microseconds. +// This value is based on what appears to be a reasonable value as most webm +// files encountered appear to have keyframes located < 4s. +#define MAX_LOOK_AHEAD 10000000 + +// Functions for reading and seeking using WebMDemuxer required for +// nestegg_io. The 'user data' passed to these functions is the +// demuxer. +static int webmdemux_read(void* aBuffer, size_t aLength, void* aUserData) { + MOZ_ASSERT(aUserData); + MOZ_ASSERT(aLength < UINT32_MAX); + WebMDemuxer::NestEggContext* context = + reinterpret_cast<WebMDemuxer::NestEggContext*>(aUserData); + uint32_t count = aLength; + if (context->IsMediaSource()) { + int64_t length = context->GetEndDataOffset(); + int64_t position = context->GetResource()->Tell(); + MOZ_ASSERT(position <= context->GetResource()->GetLength()); + MOZ_ASSERT(position <= length); + if (length >= 0 && count + position > length) { + count = length - position; + } + MOZ_ASSERT(count <= aLength); + } + uint32_t bytes = 0; + nsresult rv = + context->GetResource()->Read(static_cast<char*>(aBuffer), count, &bytes); + bool eof = bytes < aLength; + return NS_FAILED(rv) ? -1 : eof ? 0 : 1; +} + +static int webmdemux_seek(int64_t aOffset, int aWhence, void* aUserData) { + MOZ_ASSERT(aUserData); + WebMDemuxer::NestEggContext* context = + reinterpret_cast<WebMDemuxer::NestEggContext*>(aUserData); + nsresult rv = context->GetResource()->Seek(aWhence, aOffset); + return NS_SUCCEEDED(rv) ? 0 : -1; +} + +static int64_t webmdemux_tell(void* aUserData) { + MOZ_ASSERT(aUserData); + WebMDemuxer::NestEggContext* context = + reinterpret_cast<WebMDemuxer::NestEggContext*>(aUserData); + return context->GetResource()->Tell(); +} + +static void webmdemux_log(nestegg* aContext, unsigned int aSeverity, + char const* aFormat, ...) { + if (!MOZ_LOG_TEST(gNesteggLog, LogLevel::Debug)) { + return; + } + + va_list args; + char msg[256]; + const char* sevStr; + + switch (aSeverity) { + case NESTEGG_LOG_DEBUG: + sevStr = "DBG"; + break; + case NESTEGG_LOG_INFO: + sevStr = "INF"; + break; + case NESTEGG_LOG_WARNING: + sevStr = "WRN"; + break; + case NESTEGG_LOG_ERROR: + sevStr = "ERR"; + break; + case NESTEGG_LOG_CRITICAL: + sevStr = "CRT"; + break; + default: + sevStr = "UNK"; + break; + } + + va_start(args, aFormat); + + SprintfLiteral(msg, "%p [Nestegg-%s] ", aContext, sevStr); + PR_vsnprintf(msg + strlen(msg), sizeof(msg) - strlen(msg), aFormat, args); + MOZ_LOG(gNesteggLog, LogLevel::Debug, ("%s", msg)); + + va_end(args); +} + +WebMDemuxer::NestEggContext::~NestEggContext() { + if (mContext) { + nestegg_destroy(mContext); + } +} + +int WebMDemuxer::NestEggContext::Init() { + nestegg_io io; + io.read = webmdemux_read; + io.seek = webmdemux_seek; + io.tell = webmdemux_tell; + io.userdata = this; + + // While reading the metadata, we do not really care about which nestegg + // context is being used so long that they are both initialised. + // For reading the metadata however, we will use mVideoContext. + return nestegg_init(&mContext, io, &webmdemux_log, + mParent->IsMediaSource() ? mResource.GetLength() : -1); +} + +WebMDemuxer::WebMDemuxer(MediaResource* aResource) + : WebMDemuxer(aResource, false) {} + +WebMDemuxer::WebMDemuxer(MediaResource* aResource, bool aIsMediaSource) + : mVideoContext(this, aResource), + mAudioContext(this, aResource), + mBufferedState(nullptr), + mInitData(nullptr), + mVideoTrack(0), + mAudioTrack(0), + mSeekPreroll(0), + mAudioCodec(-1), + mVideoCodec(-1), + mHasVideo(false), + mHasAudio(false), + mNeedReIndex(true), + mLastWebMBlockOffset(-1), + mIsMediaSource(aIsMediaSource) { + DDLINKCHILD("resource", aResource); + // Audio/video contexts hold a MediaResourceIndex. + DDLINKCHILD("video context", mVideoContext.GetResource()); + DDLINKCHILD("audio context", mAudioContext.GetResource()); +} + +WebMDemuxer::~WebMDemuxer() { + Reset(TrackInfo::kVideoTrack); + Reset(TrackInfo::kAudioTrack); +} + +RefPtr<WebMDemuxer::InitPromise> WebMDemuxer::Init() { + InitBufferedState(); + + if (NS_FAILED(ReadMetadata())) { + return InitPromise::CreateAndReject(NS_ERROR_DOM_MEDIA_METADATA_ERR, + __func__); + } + + if (!GetNumberTracks(TrackInfo::kAudioTrack) && + !GetNumberTracks(TrackInfo::kVideoTrack)) { + return InitPromise::CreateAndReject(NS_ERROR_DOM_MEDIA_METADATA_ERR, + __func__); + } + + return InitPromise::CreateAndResolve(NS_OK, __func__); +} + +void WebMDemuxer::InitBufferedState() { + MOZ_ASSERT(!mBufferedState); + mBufferedState = new WebMBufferedState; +} + +uint32_t WebMDemuxer::GetNumberTracks(TrackInfo::TrackType aType) const { + switch (aType) { + case TrackInfo::kAudioTrack: + return mHasAudio ? 1 : 0; + case TrackInfo::kVideoTrack: + return mHasVideo ? 1 : 0; + default: + return 0; + } +} + +UniquePtr<TrackInfo> WebMDemuxer::GetTrackInfo(TrackInfo::TrackType aType, + size_t aTrackNumber) const { + switch (aType) { + case TrackInfo::kAudioTrack: + return mInfo.mAudio.Clone(); + case TrackInfo::kVideoTrack: + return mInfo.mVideo.Clone(); + default: + return nullptr; + } +} + +already_AddRefed<MediaTrackDemuxer> WebMDemuxer::GetTrackDemuxer( + TrackInfo::TrackType aType, uint32_t aTrackNumber) { + if (GetNumberTracks(aType) <= aTrackNumber) { + return nullptr; + } + RefPtr<WebMTrackDemuxer> e = new WebMTrackDemuxer(this, aType, aTrackNumber); + DDLINKCHILD("track demuxer", e.get()); + mDemuxers.AppendElement(e); + + return e.forget(); +} + +void WebMDemuxer::Reset(TrackInfo::TrackType aType) { + if (aType == TrackInfo::kVideoTrack) { + mVideoPackets.Reset(); + } else { + mAudioPackets.Reset(); + } +} + +nsresult WebMDemuxer::ReadMetadata() { + int r = mVideoContext.Init(); + if (r == -1) { + return NS_ERROR_FAILURE; + } + if (mAudioContext.Init() == -1) { + return NS_ERROR_FAILURE; + } + + // For reading the metadata we can only use the video resource/context. + MediaResourceIndex& resource = Resource(TrackInfo::kVideoTrack); + nestegg* context = Context(TrackInfo::kVideoTrack); + + { + // Check how much data nestegg read and force feed it to BufferedState. + RefPtr<MediaByteBuffer> buffer = resource.MediaReadAt(0, resource.Tell()); + if (!buffer) { + return NS_ERROR_FAILURE; + } + mBufferedState->NotifyDataArrived(buffer->Elements(), buffer->Length(), 0); + if (mBufferedState->GetInitEndOffset() < 0) { + return NS_ERROR_FAILURE; + } + MOZ_ASSERT(mBufferedState->GetInitEndOffset() <= resource.Tell()); + } + mInitData = resource.MediaReadAt(0, mBufferedState->GetInitEndOffset()); + if (!mInitData || + mInitData->Length() != size_t(mBufferedState->GetInitEndOffset())) { + return NS_ERROR_FAILURE; + } + + unsigned int ntracks = 0; + r = nestegg_track_count(context, &ntracks); + if (r == -1) { + return NS_ERROR_FAILURE; + } + + for (unsigned int track = 0; track < ntracks; ++track) { + int id = nestegg_track_codec_id(context, track); + if (id == -1) { + return NS_ERROR_FAILURE; + } + int type = nestegg_track_type(context, track); + if (type == NESTEGG_TRACK_VIDEO && !mHasVideo) { + nestegg_video_params params; + r = nestegg_track_video_params(context, track, ¶ms); + if (r == -1) { + return NS_ERROR_FAILURE; + } + mVideoCodec = nestegg_track_codec_id(context, track); + switch (mVideoCodec) { + case NESTEGG_CODEC_VP8: + mInfo.mVideo.mMimeType = "video/vp8"; + break; + case NESTEGG_CODEC_VP9: + mInfo.mVideo.mMimeType = "video/vp9"; + break; + case NESTEGG_CODEC_AV1: + mInfo.mVideo.mMimeType = "video/av1"; + break; + default: + NS_WARNING("Unknown WebM video codec"); + return NS_ERROR_FAILURE; + } + + mInfo.mVideo.mColorPrimaries = gfxUtils::CicpToColorPrimaries( + static_cast<gfx::CICP::ColourPrimaries>(params.primaries), + gMediaDemuxerLog); + + // For VPX, this is our only chance to capture the transfer + // characteristics, which we can't get from a VPX bitstream later. + // We only need this value if the video is using the BT2020 + // colorspace, which will be determined on a per-frame basis later. + mInfo.mVideo.mTransferFunction = gfxUtils::CicpToTransferFunction( + static_cast<gfx::CICP::TransferCharacteristics>( + params.transfer_characteristics)); + + // Picture region, taking into account cropping, before scaling + // to the display size. + unsigned int cropH = params.crop_right + params.crop_left; + unsigned int cropV = params.crop_bottom + params.crop_top; + gfx::IntRect pictureRect(params.crop_left, params.crop_top, + params.width - cropH, params.height - cropV); + + // If the cropping data appears invalid then use the frame data + if (pictureRect.width <= 0 || pictureRect.height <= 0 || + pictureRect.x < 0 || pictureRect.y < 0) { + pictureRect.x = 0; + pictureRect.y = 0; + pictureRect.width = params.width; + pictureRect.height = params.height; + } + + // Validate the container-reported frame and pictureRect sizes. This + // ensures that our video frame creation code doesn't overflow. + gfx::IntSize displaySize(params.display_width, params.display_height); + gfx::IntSize frameSize(params.width, params.height); + if (!IsValidVideoRegion(frameSize, pictureRect, displaySize)) { + // Video track's frame sizes will overflow. Ignore the video track. + continue; + } + + mVideoTrack = track; + mHasVideo = true; + + mInfo.mVideo.mDisplay = displaySize; + mInfo.mVideo.mImage = frameSize; + mInfo.mVideo.SetImageRect(pictureRect); + mInfo.mVideo.SetAlpha(params.alpha_mode); + + switch (params.stereo_mode) { + case NESTEGG_VIDEO_MONO: + mInfo.mVideo.mStereoMode = StereoMode::MONO; + break; + case NESTEGG_VIDEO_STEREO_LEFT_RIGHT: + mInfo.mVideo.mStereoMode = StereoMode::LEFT_RIGHT; + break; + case NESTEGG_VIDEO_STEREO_BOTTOM_TOP: + mInfo.mVideo.mStereoMode = StereoMode::BOTTOM_TOP; + break; + case NESTEGG_VIDEO_STEREO_TOP_BOTTOM: + mInfo.mVideo.mStereoMode = StereoMode::TOP_BOTTOM; + break; + case NESTEGG_VIDEO_STEREO_RIGHT_LEFT: + mInfo.mVideo.mStereoMode = StereoMode::RIGHT_LEFT; + break; + } + uint64_t duration = 0; + r = nestegg_duration(context, &duration); + if (!r) { + mInfo.mVideo.mDuration = TimeUnit::FromNanoseconds(duration); + } + mInfo.mVideo.mCrypto = GetTrackCrypto(TrackInfo::kVideoTrack, track); + if (mInfo.mVideo.mCrypto.IsEncrypted()) { + MOZ_ASSERT(mInfo.mVideo.mCrypto.mCryptoScheme == CryptoScheme::Cenc, + "WebM should only use cenc scheme"); + mCrypto.AddInitData(u"webm"_ns, mInfo.mVideo.mCrypto.mKeyId); + } + } else if (type == NESTEGG_TRACK_AUDIO && !mHasAudio) { + nestegg_audio_params params; + r = nestegg_track_audio_params(context, track, ¶ms); + if (r == -1) { + return NS_ERROR_FAILURE; + } + if (params.rate > + static_cast<decltype(params.rate)>(AudioInfo::MAX_RATE) || + params.rate <= static_cast<decltype(params.rate)>(0) || + params.channels > AudioConfig::ChannelLayout::MAX_CHANNELS) { + return NS_ERROR_DOM_MEDIA_METADATA_ERR; + } + + mAudioTrack = track; + mHasAudio = true; + mAudioCodec = nestegg_track_codec_id(context, track); + if (mAudioCodec == NESTEGG_CODEC_VORBIS) { + mInfo.mAudio.mCodecSpecificConfig = + AudioCodecSpecificVariant{VorbisCodecSpecificData{}}; + mInfo.mAudio.mMimeType = "audio/vorbis"; + } else if (mAudioCodec == NESTEGG_CODEC_OPUS) { + uint64_t codecDelayUs = params.codec_delay / 1000; + mInfo.mAudio.mMimeType = "audio/opus"; + OpusCodecSpecificData opusCodecSpecificData; + opusCodecSpecificData.mContainerCodecDelayMicroSeconds = codecDelayUs; + mInfo.mAudio.mCodecSpecificConfig = + AudioCodecSpecificVariant{std::move(opusCodecSpecificData)}; + } + mSeekPreroll = params.seek_preroll; + mInfo.mAudio.mRate = params.rate; + mInfo.mAudio.mChannels = params.channels; + + unsigned int nheaders = 0; + r = nestegg_track_codec_data_count(context, track, &nheaders); + if (r == -1) { + return NS_ERROR_FAILURE; + } + + AutoTArray<const unsigned char*, 4> headers; + AutoTArray<size_t, 4> headerLens; + for (uint32_t header = 0; header < nheaders; ++header) { + unsigned char* data = 0; + size_t length = 0; + r = nestegg_track_codec_data(context, track, header, &data, &length); + if (r == -1) { + return NS_ERROR_FAILURE; + } + headers.AppendElement(data); + headerLens.AppendElement(length); + } + + // Vorbis has 3 headers, convert to Xiph extradata format to send them to + // the demuxer. + // TODO: This is already the format WebM stores them in. Would be nice + // to avoid having libnestegg split them only for us to pack them again, + // but libnestegg does not give us an API to access this data directly. + RefPtr<MediaByteBuffer> audioCodecSpecificBlob = + GetAudioCodecSpecificBlob(mInfo.mAudio.mCodecSpecificConfig); + if (nheaders > 1) { + if (!XiphHeadersToExtradata(audioCodecSpecificBlob, headers, + headerLens)) { + return NS_ERROR_FAILURE; + } + } else { + audioCodecSpecificBlob->AppendElements(headers[0], headerLens[0]); + } + uint64_t duration = 0; + r = nestegg_duration(context, &duration); + if (!r) { + mInfo.mAudio.mDuration = TimeUnit::FromNanoseconds(duration); + } + mInfo.mAudio.mCrypto = GetTrackCrypto(TrackInfo::kAudioTrack, track); + if (mInfo.mAudio.mCrypto.IsEncrypted()) { + MOZ_ASSERT(mInfo.mAudio.mCrypto.mCryptoScheme == CryptoScheme::Cenc, + "WebM should only use cenc scheme"); + mCrypto.AddInitData(u"webm"_ns, mInfo.mAudio.mCrypto.mKeyId); + } + } + } + return NS_OK; +} + +bool WebMDemuxer::IsSeekable() const { + return Context(TrackInfo::kVideoTrack) && + nestegg_has_cues(Context(TrackInfo::kVideoTrack)); +} + +bool WebMDemuxer::IsSeekableOnlyInBufferedRanges() const { + return Context(TrackInfo::kVideoTrack) && + !nestegg_has_cues(Context(TrackInfo::kVideoTrack)); +} + +void WebMDemuxer::EnsureUpToDateIndex() { + if (!mNeedReIndex || !mInitData) { + return; + } + AutoPinned<MediaResource> resource( + Resource(TrackInfo::kVideoTrack).GetResource()); + MediaByteRangeSet byteRanges; + nsresult rv = resource->GetCachedRanges(byteRanges); + if (NS_FAILED(rv) || byteRanges.IsEmpty()) { + return; + } + mBufferedState->UpdateIndex(byteRanges, resource); + + mNeedReIndex = false; + + if (!mIsMediaSource) { + return; + } + mLastWebMBlockOffset = mBufferedState->GetLastBlockOffset(); + MOZ_ASSERT(mLastWebMBlockOffset <= resource->GetLength()); +} + +void WebMDemuxer::NotifyDataArrived() { + WEBM_DEBUG(""); + mNeedReIndex = true; +} + +void WebMDemuxer::NotifyDataRemoved() { + mBufferedState->Reset(); + if (mInitData) { + mBufferedState->NotifyDataArrived(mInitData->Elements(), + mInitData->Length(), 0); + } + mNeedReIndex = true; +} + +UniquePtr<EncryptionInfo> WebMDemuxer::GetCrypto() { + return mCrypto.IsEncrypted() ? MakeUnique<EncryptionInfo>(mCrypto) : nullptr; +} + +CryptoTrack WebMDemuxer::GetTrackCrypto(TrackInfo::TrackType aType, + size_t aTrackNumber) { + const int WEBM_IV_SIZE = 16; + const unsigned char* contentEncKeyId; + size_t contentEncKeyIdLength; + CryptoTrack crypto; + nestegg* context = Context(aType); + + int r = nestegg_track_content_enc_key_id( + context, aTrackNumber, &contentEncKeyId, &contentEncKeyIdLength); + + if (r == -1) { + WEBM_DEBUG("nestegg_track_content_enc_key_id failed r=%d", r); + return crypto; + } + + uint32_t i; + nsTArray<uint8_t> initData; + for (i = 0; i < contentEncKeyIdLength; i++) { + initData.AppendElement(contentEncKeyId[i]); + } + + if (!initData.IsEmpty()) { + // Webm only uses a cenc style scheme. + crypto.mCryptoScheme = CryptoScheme::Cenc; + crypto.mIVSize = WEBM_IV_SIZE; + crypto.mKeyId = std::move(initData); + } + + return crypto; +} + +nsresult WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, + MediaRawDataQueue* aSamples) { + if (mIsMediaSource) { + // To ensure mLastWebMBlockOffset is properly up to date. + EnsureUpToDateIndex(); + } + + RefPtr<NesteggPacketHolder> holder; + nsresult rv = NextPacket(aType, holder); + + if (NS_FAILED(rv)) { + return rv; + } + + int r = 0; + unsigned int count = 0; + r = nestegg_packet_count(holder->Packet(), &count); + if (r == -1) { + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + int64_t tstamp = holder->Timestamp(); + int64_t duration = holder->Duration(); + + // The end time of this frame is the start time of the next frame. Fetch + // the timestamp of the next packet for this track. If we've reached the + // end of the resource, use the file's duration as the end time of this + // video frame. + RefPtr<NesteggPacketHolder> next_holder; + rv = NextPacket(aType, next_holder); + if (NS_FAILED(rv) && rv != NS_ERROR_DOM_MEDIA_END_OF_STREAM) { + return rv; + } + + int64_t next_tstamp = INT64_MIN; + auto calculateNextTimestamp = [&](auto&& pushPacket, auto&& lastFrameTime, + int64_t trackEndTime) { + if (next_holder) { + next_tstamp = next_holder->Timestamp(); + (this->*pushPacket)(next_holder); + } else if (duration >= 0) { + next_tstamp = tstamp + duration; + } else if (lastFrameTime.isSome()) { + next_tstamp = tstamp + (tstamp - lastFrameTime.ref()); + } else if (mIsMediaSource) { + (this->*pushPacket)(holder); + } else { + // If we can't get frame's duration, it means either we need to wait for + // more data for MSE case or this is the last frame for file resource + // case. + if (tstamp > trackEndTime) { + // This shouldn't happen, but some muxers give incorrect durations to + // segments, then have samples appear beyond those durations. + WEBM_DEBUG("Found tstamp=%" PRIi64 " > trackEndTime=%" PRIi64 + " while calculating next timestamp! Indicates a bad mux! " + "Will use tstamp value.", + tstamp, trackEndTime); + } + next_tstamp = std::max<int64_t>(tstamp, trackEndTime); + } + lastFrameTime = Some(tstamp); + }; + + if (aType == TrackInfo::kAudioTrack) { + calculateNextTimestamp(&WebMDemuxer::PushAudioPacket, mLastAudioFrameTime, + mInfo.mAudio.mDuration.ToMicroseconds()); + } else { + calculateNextTimestamp(&WebMDemuxer::PushVideoPacket, mLastVideoFrameTime, + mInfo.mVideo.mDuration.ToMicroseconds()); + } + + if (mIsMediaSource && next_tstamp == INT64_MIN) { + return NS_ERROR_DOM_MEDIA_END_OF_STREAM; + } + + int64_t discardPadding = 0; + if (aType == TrackInfo::kAudioTrack) { + (void)nestegg_packet_discard_padding(holder->Packet(), &discardPadding); + } + + int packetEncryption = nestegg_packet_encryption(holder->Packet()); + + for (uint32_t i = 0; i < count; ++i) { + unsigned char* data = nullptr; + size_t length; + r = nestegg_packet_data(holder->Packet(), i, &data, &length); + if (r == -1) { + WEBM_DEBUG("nestegg_packet_data failed r=%d", r); + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + unsigned char* alphaData = nullptr; + size_t alphaLength = 0; + // Check packets for alpha information if file has declared alpha frames + // may be present. + if (mInfo.mVideo.HasAlpha()) { + r = nestegg_packet_additional_data(holder->Packet(), 1, &alphaData, + &alphaLength); + if (r == -1) { + WEBM_DEBUG( + "nestegg_packet_additional_data failed to retrieve alpha data r=%d", + r); + } + } + bool isKeyframe = false; + if (aType == TrackInfo::kAudioTrack) { + isKeyframe = true; + } else if (aType == TrackInfo::kVideoTrack) { + if (packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_ENCRYPTED || + packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_PARTITIONED) { + // Packet is encrypted, can't peek, use packet info + isKeyframe = nestegg_packet_has_keyframe(holder->Packet()) == + NESTEGG_PACKET_HAS_KEYFRAME_TRUE; + } else { + MOZ_ASSERT( + packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_UNENCRYPTED || + packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_FALSE, + "Unencrypted packet expected"); + auto sample = Span(data, length); + auto alphaSample = Span(alphaData, alphaLength); + + switch (mVideoCodec) { + case NESTEGG_CODEC_VP8: + isKeyframe = VPXDecoder::IsKeyframe(sample, VPXDecoder::Codec::VP8); + if (isKeyframe && alphaLength) { + isKeyframe = + VPXDecoder::IsKeyframe(alphaSample, VPXDecoder::Codec::VP8); + } + break; + case NESTEGG_CODEC_VP9: + isKeyframe = VPXDecoder::IsKeyframe(sample, VPXDecoder::Codec::VP9); + if (isKeyframe && alphaLength) { + isKeyframe = + VPXDecoder::IsKeyframe(alphaSample, VPXDecoder::Codec::VP9); + } + break; +#ifdef MOZ_AV1 + case NESTEGG_CODEC_AV1: + isKeyframe = AOMDecoder::IsKeyframe(sample); + if (isKeyframe && alphaLength) { + isKeyframe = AOMDecoder::IsKeyframe(alphaSample); + } + break; +#endif + default: + NS_WARNING("Cannot detect keyframes in unknown WebM video codec"); + return NS_ERROR_FAILURE; + } + } + } + + WEBM_DEBUG("push sample tstamp: %" PRId64 " next_tstamp: %" PRId64 + " length: %zu kf: %d", + tstamp, next_tstamp, length, isKeyframe); + RefPtr<MediaRawData> sample; + if (mInfo.mVideo.HasAlpha() && alphaLength != 0) { + sample = new MediaRawData(data, length, alphaData, alphaLength); + if ((length && !sample->Data()) || + (alphaLength && !sample->AlphaData())) { + // OOM. + return NS_ERROR_OUT_OF_MEMORY; + } + } else { + sample = new MediaRawData(data, length); + if (length && !sample->Data()) { + // OOM. + return NS_ERROR_OUT_OF_MEMORY; + } + } + sample->mTimecode = TimeUnit::FromMicroseconds(tstamp); + sample->mTime = TimeUnit::FromMicroseconds(tstamp); + if (next_tstamp > tstamp) { + sample->mDuration = TimeUnit::FromMicroseconds(next_tstamp - tstamp); + } + sample->mOffset = holder->Offset(); + sample->mKeyframe = isKeyframe; + if (discardPadding && i == count - 1) { + CheckedInt64 discardFrames; + if (discardPadding < 0) { + // This is an invalid value as discard padding should never be negative. + // Set to maximum value so that the decoder will reject it as it's + // greater than the number of frames available. + discardFrames = INT32_MAX; + WEBM_DEBUG("Invalid negative discard padding"); + } else { + discardFrames = TimeUnitToFrames( + TimeUnit::FromNanoseconds(discardPadding), mInfo.mAudio.mRate); + } + if (discardFrames.isValid()) { + sample->mDiscardPadding = discardFrames.value(); + } + } + + if (packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_ENCRYPTED || + packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_PARTITIONED) { + UniquePtr<MediaRawDataWriter> writer(sample->CreateWriter()); + unsigned char const* iv; + size_t ivLength; + nestegg_packet_iv(holder->Packet(), &iv, &ivLength); + writer->mCrypto.mCryptoScheme = CryptoScheme::Cenc; + writer->mCrypto.mIVSize = ivLength; + if (ivLength == 0) { + // Frame is not encrypted. This shouldn't happen as it means the + // encryption bit is set on a frame with no IV, but we gracefully + // handle incase. + MOZ_ASSERT_UNREACHABLE( + "Unencrypted packets should not have the encryption bit set!"); + WEBM_DEBUG("Unencrypted packet with encryption bit set"); + writer->mCrypto.mPlainSizes.AppendElement(length); + writer->mCrypto.mEncryptedSizes.AppendElement(0); + } else { + // Frame is encrypted + writer->mCrypto.mIV.AppendElements(iv, 8); + // Iv from a sample is 64 bits, must be padded with 64 bits more 0s + // in compliance with spec + for (uint32_t i = 0; i < 8; i++) { + writer->mCrypto.mIV.AppendElement(0); + } + + if (packetEncryption == NESTEGG_PACKET_HAS_SIGNAL_BYTE_ENCRYPTED) { + writer->mCrypto.mPlainSizes.AppendElement(0); + writer->mCrypto.mEncryptedSizes.AppendElement(length); + } else if (packetEncryption == + NESTEGG_PACKET_HAS_SIGNAL_BYTE_PARTITIONED) { + uint8_t numPartitions = 0; + const uint32_t* partitions = NULL; + nestegg_packet_offsets(holder->Packet(), &partitions, &numPartitions); + + // WebM stores a list of 'partitions' in the data, which alternate + // clear, encrypted. The data in the first partition is always clear. + // So, and sample might look as follows: + // 00|XXXX|000|XX, where | represents a partition, 0 a clear byte and + // X an encrypted byte. If the first bytes in sample are unencrypted, + // the first partition will be at zero |XXXX|000|XX. + // + // As GMP expects the lengths of the clear and encrypted chunks of + // data, we calculate these from the difference between the last two + // partitions. + uint32_t lastOffset = 0; + bool encrypted = false; + + for (uint8_t i = 0; i < numPartitions; i++) { + uint32_t partition = partitions[i]; + uint32_t currentLength = partition - lastOffset; + + if (encrypted) { + writer->mCrypto.mEncryptedSizes.AppendElement(currentLength); + } else { + writer->mCrypto.mPlainSizes.AppendElement(currentLength); + } + + encrypted = !encrypted; + lastOffset = partition; + + MOZ_ASSERT(lastOffset <= length); + } + + // Add the data between the last offset and the end of the data. + // 000|XXX|000 + // ^---^ + if (encrypted) { + writer->mCrypto.mEncryptedSizes.AppendElement(length - lastOffset); + } else { + writer->mCrypto.mPlainSizes.AppendElement(length - lastOffset); + } + + // Make sure we have an equal number of encrypted and plain sizes (GMP + // expects this). This simple check is sufficient as there are two + // possible cases at this point: + // 1. The number of samples are even (so we don't need to do anything) + // 2. There is one more clear sample than encrypted samples, so add a + // zero length encrypted chunk. + // There can never be more encrypted partitions than clear partitions + // due to the alternating structure of the WebM samples and the + // restriction that the first chunk is always clear. + if (numPartitions % 2 == 0) { + writer->mCrypto.mEncryptedSizes.AppendElement(0); + } + + // Assert that the lengths of the encrypted and plain samples add to + // the length of the data. + MOZ_ASSERT( + ((size_t)(std::accumulate(writer->mCrypto.mPlainSizes.begin(), + writer->mCrypto.mPlainSizes.end(), 0) + + std::accumulate(writer->mCrypto.mEncryptedSizes.begin(), + writer->mCrypto.mEncryptedSizes.end(), + 0)) == length)); + } + } + } + aSamples->Push(sample); + } + return NS_OK; +} + +nsresult WebMDemuxer::NextPacket(TrackInfo::TrackType aType, + RefPtr<NesteggPacketHolder>& aPacket) { + bool isVideo = aType == TrackInfo::kVideoTrack; + + // Flag to indicate that we do need to playback these types of + // packets. + bool hasType = isVideo ? mHasVideo : mHasAudio; + + if (!hasType) { + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + + // The packet queue for the type that we are interested in. + WebMPacketQueue& packets = isVideo ? mVideoPackets : mAudioPackets; + + if (packets.GetSize() > 0) { + aPacket = packets.PopFront(); + return NS_OK; + } + + // Track we are interested in + uint32_t ourTrack = isVideo ? mVideoTrack : mAudioTrack; + + do { + RefPtr<NesteggPacketHolder> holder; + nsresult rv = DemuxPacket(aType, holder); + if (NS_FAILED(rv)) { + return rv; + } + if (!holder) { + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + + if (ourTrack == holder->Track()) { + aPacket = holder; + return NS_OK; + } + } while (true); +} + +nsresult WebMDemuxer::DemuxPacket(TrackInfo::TrackType aType, + RefPtr<NesteggPacketHolder>& aPacket) { + nestegg_packet* packet; + int r = nestegg_read_packet(Context(aType), &packet); + if (r == 0) { + nestegg_read_reset(Context(aType)); + return NS_ERROR_DOM_MEDIA_END_OF_STREAM; + } else if (r < 0) { + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + + unsigned int track = 0; + r = nestegg_packet_track(packet, &track); + if (r == -1) { + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + + int64_t offset = Resource(aType).Tell(); + RefPtr<NesteggPacketHolder> holder = new NesteggPacketHolder(); + if (!holder->Init(packet, offset, track, false)) { + return NS_ERROR_DOM_MEDIA_DEMUXER_ERR; + } + + aPacket = holder; + return NS_OK; +} + +void WebMDemuxer::PushAudioPacket(NesteggPacketHolder* aItem) { + mAudioPackets.PushFront(aItem); +} + +void WebMDemuxer::PushVideoPacket(NesteggPacketHolder* aItem) { + mVideoPackets.PushFront(aItem); +} + +nsresult WebMDemuxer::SeekInternal(TrackInfo::TrackType aType, + const TimeUnit& aTarget) { + EnsureUpToDateIndex(); + uint32_t trackToSeek = mHasVideo ? mVideoTrack : mAudioTrack; + MOZ_ASSERT(aTarget.ToNanoseconds() >= 0, "Seek time can't be negative"); + uint64_t target = static_cast<uint64_t>(aTarget.ToNanoseconds()); + + Reset(aType); + + if (mSeekPreroll) { + uint64_t startTime = 0; + if (!mBufferedState->GetStartTime(&startTime)) { + startTime = 0; + } + WEBM_DEBUG("Seek Target: %f", + TimeUnit::FromNanoseconds(target).ToSeconds()); + if (target < mSeekPreroll || target - mSeekPreroll < startTime) { + target = startTime; + } else { + target -= mSeekPreroll; + } + WEBM_DEBUG("SeekPreroll: %f StartTime: %f Adjusted Target: %f", + TimeUnit::FromNanoseconds(mSeekPreroll).ToSeconds(), + TimeUnit::FromNanoseconds(startTime).ToSeconds(), + TimeUnit::FromNanoseconds(target).ToSeconds()); + } + int r = nestegg_track_seek(Context(aType), trackToSeek, target); + if (r == -1) { + WEBM_DEBUG("track_seek for track %u to %f failed, r=%d", trackToSeek, + TimeUnit::FromNanoseconds(target).ToSeconds(), r); + // Try seeking directly based on cluster information in memory. + int64_t offset = 0; + bool rv = mBufferedState->GetOffsetForTime(target, &offset); + if (!rv) { + WEBM_DEBUG("mBufferedState->GetOffsetForTime failed too"); + return NS_ERROR_FAILURE; + } + + if (offset < 0) { + WEBM_DEBUG("Unknow byte offset time for seek target %" PRIu64 "ns", + target); + return NS_ERROR_FAILURE; + } + + r = nestegg_offset_seek(Context(aType), static_cast<uint64_t>(offset)); + if (r == -1) { + WEBM_DEBUG("and nestegg_offset_seek to %" PRIu64 " failed", offset); + return NS_ERROR_FAILURE; + } + WEBM_DEBUG("got offset from buffered state: %" PRIu64 "", offset); + } + + if (aType == TrackInfo::kAudioTrack) { + mLastAudioFrameTime.reset(); + } else { + mLastVideoFrameTime.reset(); + } + + return NS_OK; +} + +bool WebMDemuxer::IsBufferedIntervalValid(uint64_t start, uint64_t end) { + if (start > end) { + // Buffered ranges are clamped to the media's start time and duration. Any + // frames with timestamps outside that range are ignored, see bug 1697641 + // for more info. + WEBM_DEBUG("Ignoring range %" PRIu64 "-%" PRIu64 + ", due to invalid interval (start > end).", + start, end); + return false; + } + + auto startTime = TimeUnit::FromNanoseconds(start); + auto endTime = TimeUnit::FromNanoseconds(end); + + if (startTime.IsNegative() || endTime.IsNegative()) { + // We can get timestamps that are conceptually valid, but become + // negative due to uint64 -> int64 conversion from TimeUnit. We should + // not get negative timestamps, so guard against them. + WEBM_DEBUG( + "Invalid range %f-%f, likely result of uint64 -> int64 conversion.", + startTime.ToSeconds(), endTime.ToSeconds()); + return false; + } + + return true; +} + +media::TimeIntervals WebMDemuxer::GetBuffered() { + EnsureUpToDateIndex(); + AutoPinned<MediaResource> resource( + Resource(TrackInfo::kVideoTrack).GetResource()); + + media::TimeIntervals buffered; + + MediaByteRangeSet ranges; + nsresult rv = resource->GetCachedRanges(ranges); + if (NS_FAILED(rv)) { + return media::TimeIntervals(); + } + uint64_t duration = 0; + uint64_t startOffset = 0; + if (!nestegg_duration(Context(TrackInfo::kVideoTrack), &duration)) { + if (mBufferedState->GetStartTime(&startOffset)) { + duration += startOffset; + } + WEBM_DEBUG("Duration: %f StartTime: %f", + TimeUnit::FromNanoseconds(duration).ToSeconds(), + TimeUnit::FromNanoseconds(startOffset).ToSeconds()); + } + for (uint32_t index = 0; index < ranges.Length(); index++) { + uint64_t start, end; + bool rv = mBufferedState->CalculateBufferedForRange( + ranges[index].mStart, ranges[index].mEnd, &start, &end); + if (rv) { + NS_ASSERTION(startOffset <= start, + "startOffset negative or larger than start time"); + + if (duration && end > duration) { + WEBM_DEBUG("limit range to duration, end: %f duration: %f", + TimeUnit::FromNanoseconds(end).ToSeconds(), + TimeUnit::FromNanoseconds(duration).ToSeconds()); + end = duration; + } + + if (!IsBufferedIntervalValid(start, end)) { + WEBM_DEBUG("Invalid interval, bailing"); + break; + } + + auto startTime = TimeUnit::FromNanoseconds(start); + auto endTime = TimeUnit::FromNanoseconds(end); + + WEBM_DEBUG("add range %f-%f", startTime.ToSeconds(), endTime.ToSeconds()); + buffered += media::TimeInterval(startTime, endTime); + } + } + return buffered; +} + +bool WebMDemuxer::GetOffsetForTime(uint64_t aTime, int64_t* aOffset) { + EnsureUpToDateIndex(); + return mBufferedState && mBufferedState->GetOffsetForTime(aTime, aOffset); +} + +// WebMTrackDemuxer +WebMTrackDemuxer::WebMTrackDemuxer(WebMDemuxer* aParent, + TrackInfo::TrackType aType, + uint32_t aTrackNumber) + : mParent(aParent), mType(aType), mNeedKeyframe(true) { + mInfo = mParent->GetTrackInfo(aType, aTrackNumber); + MOZ_ASSERT(mInfo); +} + +WebMTrackDemuxer::~WebMTrackDemuxer() { mSamples.Reset(); } + +UniquePtr<TrackInfo> WebMTrackDemuxer::GetInfo() const { + return mInfo->Clone(); +} + +RefPtr<WebMTrackDemuxer::SeekPromise> WebMTrackDemuxer::Seek( + const TimeUnit& aTime) { + // Seeks to aTime. Upon success, SeekPromise will be resolved with the + // actual time seeked to. Typically the random access point time + + auto seekTime = aTime; + bool keyframe = false; + + mNeedKeyframe = true; + + do { + mSamples.Reset(); + mParent->SeekInternal(mType, seekTime); + nsresult rv = mParent->GetNextPacket(mType, &mSamples); + if (NS_FAILED(rv)) { + if (rv == NS_ERROR_DOM_MEDIA_END_OF_STREAM) { + // Ignore the error for now, the next GetSample will be rejected with + // EOS. + return SeekPromise::CreateAndResolve(TimeUnit::Zero(), __func__); + } + return SeekPromise::CreateAndReject(rv, __func__); + } + + // Check what time we actually seeked to. + if (mSamples.GetSize() == 0) { + // We can't determine if the seek succeeded at this stage, so break the + // loop. + break; + } + + for (const auto& sample : mSamples) { + seekTime = sample->mTime; + keyframe = sample->mKeyframe; + if (keyframe) { + break; + } + } + if (mType == TrackInfo::kVideoTrack && + !mInfo->GetAsVideoInfo()->HasAlpha()) { + // We only perform a search for a keyframe on videos with alpha layer to + // prevent potential regression for normal video (even though invalid) + break; + } + if (!keyframe) { + // We didn't find any keyframe, attempt to seek to the previous cluster. + seekTime = mSamples.First()->mTime - TimeUnit::FromMicroseconds(1); + } + } while (!keyframe && seekTime >= TimeUnit::Zero()); + + SetNextKeyFrameTime(); + + return SeekPromise::CreateAndResolve(seekTime, __func__); +} + +nsresult WebMTrackDemuxer::NextSample(RefPtr<MediaRawData>& aData) { + nsresult rv = NS_ERROR_DOM_MEDIA_END_OF_STREAM; + while (mSamples.GetSize() < 1 && + NS_SUCCEEDED((rv = mParent->GetNextPacket(mType, &mSamples)))) { + } + if (mSamples.GetSize()) { + aData = mSamples.PopFront(); + return NS_OK; + } + return rv; +} + +RefPtr<WebMTrackDemuxer::SamplesPromise> WebMTrackDemuxer::GetSamples( + int32_t aNumSamples) { + RefPtr<SamplesHolder> samples = new SamplesHolder; + MOZ_ASSERT(aNumSamples); + + nsresult rv = NS_ERROR_DOM_MEDIA_END_OF_STREAM; + + while (aNumSamples) { + RefPtr<MediaRawData> sample; + rv = NextSample(sample); + if (NS_FAILED(rv)) { + break; + } + // Ignore empty samples. + if (sample->Size() == 0) { + WEBM_DEBUG( + "0 sized sample encountered while getting samples, skipping it"); + continue; + } + if (mNeedKeyframe && !sample->mKeyframe) { + continue; + } + if (!sample->HasValidTime()) { + return SamplesPromise::CreateAndReject(NS_ERROR_DOM_MEDIA_DEMUXER_ERR, + __func__); + } + mNeedKeyframe = false; + samples->AppendSample(sample); + aNumSamples--; + } + + if (samples->GetSamples().IsEmpty()) { + return SamplesPromise::CreateAndReject(rv, __func__); + } else { + UpdateSamples(samples->GetSamples()); + return SamplesPromise::CreateAndResolve(samples, __func__); + } +} + +void WebMTrackDemuxer::SetNextKeyFrameTime() { + if (mType != TrackInfo::kVideoTrack || mParent->IsMediaSource()) { + return; + } + + auto frameTime = TimeUnit::Invalid(); + + mNextKeyframeTime.reset(); + + MediaRawDataQueue skipSamplesQueue; + bool foundKeyframe = false; + while (!foundKeyframe && mSamples.GetSize()) { + RefPtr<MediaRawData> sample = mSamples.PopFront(); + if (sample->mKeyframe) { + frameTime = sample->mTime; + foundKeyframe = true; + } + skipSamplesQueue.Push(sample.forget()); + } + Maybe<int64_t> startTime; + if (skipSamplesQueue.GetSize()) { + const RefPtr<MediaRawData>& sample = skipSamplesQueue.First(); + startTime.emplace(sample->mTimecode.ToMicroseconds()); + } + // Demux and buffer frames until we find a keyframe. + RefPtr<MediaRawData> sample; + nsresult rv = NS_OK; + while (!foundKeyframe && NS_SUCCEEDED((rv = NextSample(sample)))) { + if (sample->mKeyframe) { + frameTime = sample->mTime; + foundKeyframe = true; + } + int64_t sampleTimecode = sample->mTimecode.ToMicroseconds(); + skipSamplesQueue.Push(sample.forget()); + if (!startTime) { + startTime.emplace(sampleTimecode); + } else if (!foundKeyframe && + sampleTimecode > startTime.ref() + MAX_LOOK_AHEAD) { + WEBM_DEBUG("Couldn't find keyframe in a reasonable time, aborting"); + break; + } + } + // We may have demuxed more than intended, so ensure that all frames are kept + // in the right order. + mSamples.PushFront(std::move(skipSamplesQueue)); + + if (frameTime.IsValid()) { + mNextKeyframeTime.emplace(frameTime); + WEBM_DEBUG( + "Next Keyframe %f (%u queued %.02fs)", + mNextKeyframeTime.value().ToSeconds(), uint32_t(mSamples.GetSize()), + (mSamples.Last()->mTimecode - mSamples.First()->mTimecode).ToSeconds()); + } else { + WEBM_DEBUG("Couldn't determine next keyframe time (%u queued)", + uint32_t(mSamples.GetSize())); + } +} + +void WebMTrackDemuxer::Reset() { + mSamples.Reset(); + media::TimeIntervals buffered = GetBuffered(); + mNeedKeyframe = true; + if (!buffered.IsEmpty()) { + WEBM_DEBUG("Seek to start point: %f", buffered.Start(0).ToSeconds()); + mParent->SeekInternal(mType, buffered.Start(0)); + SetNextKeyFrameTime(); + } else { + mNextKeyframeTime.reset(); + } +} + +void WebMTrackDemuxer::UpdateSamples( + const nsTArray<RefPtr<MediaRawData>>& aSamples) { + for (const auto& sample : aSamples) { + if (sample->mCrypto.IsEncrypted()) { + UniquePtr<MediaRawDataWriter> writer(sample->CreateWriter()); + writer->mCrypto.mIVSize = mInfo->mCrypto.mIVSize; + writer->mCrypto.mKeyId.AppendElements(mInfo->mCrypto.mKeyId); + } + } + if (mNextKeyframeTime.isNothing() || + aSamples.LastElement()->mTime >= mNextKeyframeTime.value()) { + SetNextKeyFrameTime(); + } +} + +nsresult WebMTrackDemuxer::GetNextRandomAccessPoint(TimeUnit* aTime) { + if (mNextKeyframeTime.isNothing()) { + // There's no next key frame. + *aTime = TimeUnit::FromInfinity(); + } else { + *aTime = mNextKeyframeTime.ref(); + } + return NS_OK; +} + +RefPtr<WebMTrackDemuxer::SkipAccessPointPromise> +WebMTrackDemuxer::SkipToNextRandomAccessPoint(const TimeUnit& aTimeThreshold) { + uint32_t parsed = 0; + bool found = false; + RefPtr<MediaRawData> sample; + nsresult rv = NS_OK; + + WEBM_DEBUG("TimeThreshold: %f", aTimeThreshold.ToSeconds()); + while (!found && NS_SUCCEEDED((rv = NextSample(sample)))) { + parsed++; + if (sample->mKeyframe && sample->mTime >= aTimeThreshold) { + WEBM_DEBUG("next sample: %f (parsed: %d)", sample->mTime.ToSeconds(), + parsed); + found = true; + mSamples.Reset(); + mSamples.PushFront(sample.forget()); + } + } + if (NS_SUCCEEDED(rv)) { + SetNextKeyFrameTime(); + } + if (found) { + return SkipAccessPointPromise::CreateAndResolve(parsed, __func__); + } else { + SkipFailureHolder failure(NS_ERROR_DOM_MEDIA_END_OF_STREAM, parsed); + return SkipAccessPointPromise::CreateAndReject(std::move(failure), + __func__); + } +} + +media::TimeIntervals WebMTrackDemuxer::GetBuffered() { + return mParent->GetBuffered(); +} + +void WebMTrackDemuxer::BreakCycles() { mParent = nullptr; } + +int64_t WebMTrackDemuxer::GetEvictionOffset(const TimeUnit& aTime) { + int64_t offset; + int64_t nanos = aTime.ToNanoseconds(); + if (nanos < 0 || + !mParent->GetOffsetForTime(static_cast<uint64_t>(nanos), &offset)) { + return 0; + } + + return offset; +} +} // namespace mozilla + +#undef WEBM_DEBUG |