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gecko-dev/content/media/ogg/nsOggReader.cpp

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/* -*- 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 "nsBuiltinDecoderStateMachine.h"
#include "nsBuiltinDecoder.h"
#include "nsOggReader.h"
#include "VideoUtils.h"
#include "theora/theoradec.h"
#ifdef MOZ_OPUS
#include "opus/opus.h"
#endif
#include "nsTimeRanges.h"
#include "mozilla/TimeStamp.h"
using namespace mozilla;
// Un-comment to enable logging of seek bisections.
//#define SEEK_LOGGING
#ifdef PR_LOGGING
extern PRLogModuleInfo* gBuiltinDecoderLog;
#define LOG(type, msg) PR_LOG(gBuiltinDecoderLog, type, msg)
#ifdef SEEK_LOGGING
#define SEEK_LOG(type, msg) PR_LOG(gBuiltinDecoderLog, type, msg)
#else
#define SEEK_LOG(type, msg)
#endif
#else
#define LOG(type, msg)
#define SEEK_LOG(type, msg)
#endif
// The number of microseconds of "fuzz" we use in a bisection search over
// HTTP. When we're seeking with fuzz, we'll stop the search if a bisection
// lands between the seek target and SEEK_FUZZ_USECS microseconds before the
// seek target. This is becaue it's usually quicker to just keep downloading
// from an exisiting connection than to do another bisection inside that
// small range, which would open a new HTTP connetion.
static const PRUint32 SEEK_FUZZ_USECS = 500000;
// The number of microseconds of "pre-roll" we use for Opus streams.
// The specification recommends 80 ms.
static const PRInt64 SEEK_OPUS_PREROLL = 80 * USECS_PER_MS;
enum PageSyncResult {
PAGE_SYNC_ERROR = 1,
PAGE_SYNC_END_OF_RANGE= 2,
PAGE_SYNC_OK = 3
};
// Reads a page from the media resource.
static PageSyncResult
PageSync(MediaResource* aResource,
ogg_sync_state* aState,
bool aCachedDataOnly,
PRInt64 aOffset,
PRInt64 aEndOffset,
ogg_page* aPage,
int& aSkippedBytes);
// Chunk size to read when reading Ogg files. Average Ogg page length
// is about 4300 bytes, so we read the file in chunks larger than that.
static const int PAGE_STEP = 8192;
nsOggReader::nsOggReader(nsBuiltinDecoder* aDecoder)
: nsBuiltinDecoderReader(aDecoder),
mTheoraState(nullptr),
mVorbisState(nullptr),
mOpusState(nullptr),
mOpusEnabled(nsHTMLMediaElement::IsOpusEnabled()),
mSkeletonState(nullptr),
mVorbisSerial(0),
mOpusSerial(0),
mTheoraSerial(0),
mOpusPreSkip(0),
mPageOffset(0)
{
MOZ_COUNT_CTOR(nsOggReader);
memset(&mTheoraInfo, 0, sizeof(mTheoraInfo));
}
nsOggReader::~nsOggReader()
{
ogg_sync_clear(&mOggState);
MOZ_COUNT_DTOR(nsOggReader);
}
nsresult nsOggReader::Init(nsBuiltinDecoderReader* aCloneDonor) {
mCodecStates.Init();
int ret = ogg_sync_init(&mOggState);
NS_ENSURE_TRUE(ret == 0, NS_ERROR_FAILURE);
return NS_OK;
}
nsresult nsOggReader::ResetDecode()
{
return ResetDecode(false);
}
nsresult nsOggReader::ResetDecode(bool start)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
nsresult res = NS_OK;
if (NS_FAILED(nsBuiltinDecoderReader::ResetDecode())) {
res = NS_ERROR_FAILURE;
}
// Discard any previously buffered packets/pages.
ogg_sync_reset(&mOggState);
if (mVorbisState && NS_FAILED(mVorbisState->Reset())) {
res = NS_ERROR_FAILURE;
}
if (mOpusState && NS_FAILED(mOpusState->Reset(start))) {
res = NS_ERROR_FAILURE;
}
if (mTheoraState && NS_FAILED(mTheoraState->Reset())) {
res = NS_ERROR_FAILURE;
}
return res;
}
bool nsOggReader::ReadHeaders(nsOggCodecState* aState)
{
while (!aState->DoneReadingHeaders()) {
ogg_packet* packet = NextOggPacket(aState);
// DecodeHeader is responsible for releasing packet.
if (!packet || !aState->DecodeHeader(packet)) {
aState->Deactivate();
return false;
}
}
return aState->Init();
}
void nsOggReader::BuildSerialList(nsTArray<PRUint32>& aTracks)
{
if (HasVideo()) {
aTracks.AppendElement(mTheoraState->mSerial);
}
if (HasAudio()) {
if (mVorbisState) {
aTracks.AppendElement(mVorbisState->mSerial);
} else if(mOpusState) {
aTracks.AppendElement(mOpusState->mSerial);
}
}
}
static
nsHTMLMediaElement::MetadataTags* TagsFromVorbisComment(vorbis_comment *vc)
{
nsHTMLMediaElement::MetadataTags* tags;
int i;
tags = new nsHTMLMediaElement::MetadataTags;
tags->Init();
for (i = 0; i < vc->comments; i++) {
char *comment = vc->user_comments[i];
char *div = (char*)memchr(comment, '=', vc->comment_lengths[i]);
if (!div) {
LOG(PR_LOG_DEBUG, ("Invalid vorbis comment: no separator"));
continue;
}
// This should be ASCII.
nsCString key = nsCString(comment, div-comment);
PRUint32 value_length = vc->comment_lengths[i] - (div-comment);
// This should be utf-8.
nsCString value = nsCString(div + 1, value_length);
tags->Put(key, value);
}
return tags;
}
nsresult nsOggReader::ReadMetadata(nsVideoInfo* aInfo,
nsHTMLMediaElement::MetadataTags** aTags)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
// We read packets until all bitstreams have read all their header packets.
// We record the offset of the first non-header page so that we know
// what page to seek to when seeking to the media start.
NS_ASSERTION(aTags, "Called with null MetadataTags**.");
*aTags = nullptr;
ogg_page page;
nsAutoTArray<nsOggCodecState*,4> bitstreams;
bool readAllBOS = false;
while (!readAllBOS) {
PRInt64 pageOffset = ReadOggPage(&page);
if (pageOffset == -1) {
// Some kind of error...
break;
}
int serial = ogg_page_serialno(&page);
nsOggCodecState* codecState = 0;
if (!ogg_page_bos(&page)) {
// We've encountered a non Beginning Of Stream page. No more BOS pages
// can follow in this Ogg segment, so there will be no other bitstreams
// in the Ogg (unless it's invalid).
readAllBOS = true;
} else if (!mCodecStates.Get(serial, nullptr)) {
// We've not encountered a stream with this serial number before. Create
// an nsOggCodecState to demux it, and map that to the nsOggCodecState
// in mCodecStates.
codecState = nsOggCodecState::Create(&page);
mCodecStates.Put(serial, codecState);
bitstreams.AppendElement(codecState);
mKnownStreams.AppendElement(serial);
if (codecState &&
codecState->GetType() == nsOggCodecState::TYPE_VORBIS &&
!mVorbisState)
{
// First Vorbis bitstream, we'll play this one. Subsequent Vorbis
// bitstreams will be ignored.
mVorbisState = static_cast<nsVorbisState*>(codecState);
}
if (codecState &&
codecState->GetType() == nsOggCodecState::TYPE_THEORA &&
!mTheoraState)
{
// First Theora bitstream, we'll play this one. Subsequent Theora
// bitstreams will be ignored.
mTheoraState = static_cast<nsTheoraState*>(codecState);
}
if (codecState &&
codecState->GetType() == nsOggCodecState::TYPE_OPUS &&
!mOpusState)
{
if (mOpusEnabled) {
mOpusState = static_cast<nsOpusState*>(codecState);
} else {
NS_WARNING("Opus decoding disabled."
" See media.opus.enabled in about:config");
}
}
if (codecState &&
codecState->GetType() == nsOggCodecState::TYPE_SKELETON &&
!mSkeletonState)
{
mSkeletonState = static_cast<nsSkeletonState*>(codecState);
}
}
mCodecStates.Get(serial, &codecState);
NS_ENSURE_TRUE(codecState, NS_ERROR_FAILURE);
if (NS_FAILED(codecState->PageIn(&page))) {
return NS_ERROR_FAILURE;
}
}
// We've read all BOS pages, so we know the streams contained in the media.
// Now process all available header packets in the active Theora, Vorbis and
// Skeleton streams.
// Deactivate any non-primary bitstreams.
for (PRUint32 i = 0; i < bitstreams.Length(); i++) {
nsOggCodecState* s = bitstreams[i];
if (s != mVorbisState && s != mOpusState &&
s != mTheoraState && s != mSkeletonState) {
s->Deactivate();
}
}
if (mTheoraState && ReadHeaders(mTheoraState)) {
nsIntRect picture = nsIntRect(mTheoraState->mInfo.pic_x,
mTheoraState->mInfo.pic_y,
mTheoraState->mInfo.pic_width,
mTheoraState->mInfo.pic_height);
nsIntSize displaySize = nsIntSize(mTheoraState->mInfo.pic_width,
mTheoraState->mInfo.pic_height);
// Apply the aspect ratio to produce the intrinsic display size we report
// to the element.
ScaleDisplayByAspectRatio(displaySize, mTheoraState->mPixelAspectRatio);
nsIntSize frameSize(mTheoraState->mInfo.frame_width,
mTheoraState->mInfo.frame_height);
if (nsVideoInfo::ValidateVideoRegion(frameSize, picture, displaySize)) {
// Video track's frame sizes will not overflow. Activate the video track.
mInfo.mHasVideo = true;
mInfo.mDisplay = displaySize;
mPicture = picture;
VideoFrameContainer* container = mDecoder->GetVideoFrameContainer();
if (container) {
container->SetCurrentFrame(gfxIntSize(displaySize.width, displaySize.height),
nullptr,
TimeStamp::Now());
}
// Copy Theora info data for time computations on other threads.
memcpy(&mTheoraInfo, &mTheoraState->mInfo, sizeof(mTheoraInfo));
mTheoraSerial = mTheoraState->mSerial;
}
}
if (mVorbisState && ReadHeaders(mVorbisState)) {
mInfo.mHasAudio = true;
mInfo.mAudioRate = mVorbisState->mInfo.rate;
mInfo.mAudioChannels = mVorbisState->mInfo.channels;
// Copy Vorbis info data for time computations on other threads.
memcpy(&mVorbisInfo, &mVorbisState->mInfo, sizeof(mVorbisInfo));
mVorbisInfo.codec_setup = NULL;
mVorbisSerial = mVorbisState->mSerial;
*aTags = TagsFromVorbisComment(&mVorbisState->mComment);
} else {
memset(&mVorbisInfo, 0, sizeof(mVorbisInfo));
}
#ifdef MOZ_OPUS
if (mOpusState && ReadHeaders(mOpusState)) {
mInfo.mHasAudio = true;
mInfo.mAudioRate = mOpusState->mRate;
mInfo.mAudioChannels = mOpusState->mChannels;
mOpusSerial = mOpusState->mSerial;
mOpusPreSkip = mOpusState->mPreSkip;
}
#endif
if (mSkeletonState) {
if (!HasAudio() && !HasVideo()) {
// We have a skeleton track, but no audio or video, may as well disable
// the skeleton, we can't do anything useful with this media.
mSkeletonState->Deactivate();
} else if (ReadHeaders(mSkeletonState) && mSkeletonState->HasIndex()) {
// Extract the duration info out of the index, so we don't need to seek to
// the end of resource to get it.
nsAutoTArray<PRUint32, 2> tracks;
BuildSerialList(tracks);
PRInt64 duration = 0;
if (NS_SUCCEEDED(mSkeletonState->GetDuration(tracks, duration))) {
ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
mDecoder->GetStateMachine()->SetDuration(duration);
LOG(PR_LOG_DEBUG, ("Got duration from Skeleton index %lld", duration));
}
}
}
if (HasAudio() || HasVideo()) {
ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
MediaResource* resource = mDecoder->GetResource();
if (mDecoder->GetStateMachine()->GetDuration() == -1 &&
mDecoder->GetStateMachine()->GetState() != nsDecoderStateMachine::DECODER_STATE_SHUTDOWN &&
resource->GetLength() >= 0 &&
mDecoder->GetStateMachine()->IsSeekable())
{
// We didn't get a duration from the index or a Content-Duration header.
// Seek to the end of file to find the end time.
PRInt64 length = resource->GetLength();
NS_ASSERTION(length > 0, "Must have a content length to get end time");
PRInt64 endTime = 0;
{
ReentrantMonitorAutoExit exitMon(mDecoder->GetReentrantMonitor());
endTime = RangeEndTime(length);
}
if (endTime != -1) {
mDecoder->GetStateMachine()->SetEndTime(endTime);
LOG(PR_LOG_DEBUG, ("Got Ogg duration from seeking to end %lld", endTime));
}
}
} else {
return NS_ERROR_FAILURE;
}
*aInfo = mInfo;
return NS_OK;
}
nsresult nsOggReader::DecodeVorbis(ogg_packet* aPacket) {
NS_ASSERTION(aPacket->granulepos != -1, "Must know vorbis granulepos!");
if (vorbis_synthesis(&mVorbisState->mBlock, aPacket) != 0) {
return NS_ERROR_FAILURE;
}
if (vorbis_synthesis_blockin(&mVorbisState->mDsp,
&mVorbisState->mBlock) != 0)
{
return NS_ERROR_FAILURE;
}
VorbisPCMValue** pcm = 0;
PRInt32 frames = 0;
PRUint32 channels = mVorbisState->mInfo.channels;
ogg_int64_t endFrame = aPacket->granulepos;
while ((frames = vorbis_synthesis_pcmout(&mVorbisState->mDsp, &pcm)) > 0) {
mVorbisState->ValidateVorbisPacketSamples(aPacket, frames);
nsAutoArrayPtr<AudioDataValue> buffer(new AudioDataValue[frames * channels]);
for (PRUint32 j = 0; j < channels; ++j) {
VorbisPCMValue* channel = pcm[j];
for (PRUint32 i = 0; i < PRUint32(frames); ++i) {
buffer[i*channels + j] = MOZ_CONVERT_VORBIS_SAMPLE(channel[i]);
}
}
PRInt64 duration = mVorbisState->Time((PRInt64)frames);
PRInt64 startTime = mVorbisState->Time(endFrame - frames);
mAudioQueue.Push(new AudioData(mPageOffset,
startTime,
duration,
frames,
buffer.forget(),
channels));
endFrame -= frames;
if (vorbis_synthesis_read(&mVorbisState->mDsp, frames) != 0) {
return NS_ERROR_FAILURE;
}
}
return NS_OK;
}
#ifdef MOZ_OPUS
nsresult nsOggReader::DecodeOpus(ogg_packet* aPacket) {
NS_ASSERTION(aPacket->granulepos != -1, "Must know opus granulepos!");
// Maximum value is 63*2880.
PRInt32 frames = opus_decoder_get_nb_samples(mOpusState->mDecoder,
aPacket->packet,
aPacket->bytes);
if (frames <= 0)
return NS_ERROR_FAILURE;
PRUint32 channels = mOpusState->mChannels;
nsAutoArrayPtr<AudioDataValue> buffer(new AudioDataValue[frames * channels]);
// Decode to the appropriate sample type.
#ifdef MOZ_SAMPLE_TYPE_FLOAT32
int ret = opus_decode_float(mOpusState->mDecoder,
aPacket->packet, aPacket->bytes,
buffer, frames, false);
#else
int ret = opus_decode(mOpusState->mDecoder,
aPacket->packet, aPacket->bytes,
buffer, frames, false);
#endif
if (ret < 0)
return NS_ERROR_FAILURE;
NS_ASSERTION(ret == frames, "Opus decoded too few audio samples");
PRInt64 endFrame = aPacket->granulepos;
PRInt64 startFrame;
// If this is the last packet, perform end trimming.
if (aPacket->e_o_s && mOpusState->mPrevPacketGranulepos != -1) {
startFrame = mOpusState->mPrevPacketGranulepos;
frames = static_cast<PRInt32>(NS_MAX(static_cast<PRInt64>(0),
NS_MIN(endFrame - startFrame,
static_cast<PRInt64>(frames))));
} else {
startFrame = endFrame - frames;
}
// Trim the initial frames while the decoder is settling.
if (mOpusState->mSkip > 0) {
PRInt32 skipFrames = NS_MIN(mOpusState->mSkip, frames);
if (skipFrames == frames) {
// discard the whole packet
mOpusState->mSkip -= frames;
LOG(PR_LOG_DEBUG, ("Opus decoder skipping %d frames"
" (whole packet)", frames));
return NS_OK;
}
PRInt32 keepFrames = frames - skipFrames;
int samples = keepFrames * channels;
nsAutoArrayPtr<AudioDataValue> trimBuffer(new AudioDataValue[samples]);
for (int i = 0; i < samples; i++)
trimBuffer[i] = buffer[skipFrames*channels + i];
startFrame = endFrame - keepFrames;
frames = keepFrames;
buffer = trimBuffer;
mOpusState->mSkip -= skipFrames;
LOG(PR_LOG_DEBUG, ("Opus decoder skipping %d frames", skipFrames));
}
// Save this packet's granule position in case we need to perform end
// trimming on the next packet.
mOpusState->mPrevPacketGranulepos = endFrame;
// Apply the header gain if one was specified.
#ifdef MOZ_SAMPLE_TYPE_FLOAT32
if (mOpusState->mGain != 1.0f) {
float gain = mOpusState->mGain;
int samples = frames * channels;
for (int i = 0; i < samples; i++) {
buffer[i] *= gain;
}
}
#else
if (mOpusState->mGain_Q16 != 65536) {
PRInt64 gain_Q16 = mOpusState->mGain_Q16;
int samples = frames * channels;
for (int i = 0; i < samples; i++) {
PRInt32 val = static_cast<PRInt32>((gain_Q16*buffer[i] + 32768)>>16);
buffer[i] = static_cast<AudioDataValue>(MOZ_CLIP_TO_15(val));
}
}
#endif
LOG(PR_LOG_DEBUG, ("Opus decoder pushing %d frames", frames));
PRInt64 startTime = mOpusState->Time(startFrame);
PRInt64 endTime = mOpusState->Time(endFrame);
mAudioQueue.Push(new AudioData(mPageOffset,
startTime,
endTime - startTime,
frames,
buffer.forget(),
channels));
return NS_OK;
}
#endif /* MOZ_OPUS */
bool nsOggReader::DecodeAudioData()
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
NS_ASSERTION(mVorbisState != nullptr || mOpusState != nullptr,
"Need audio codec state to decode audio");
// Read the next data packet. Skip any non-data packets we encounter.
ogg_packet* packet = 0;
nsOggCodecState* codecState;
if (mVorbisState)
codecState = static_cast<nsOggCodecState*>(mVorbisState);
else
codecState = static_cast<nsOggCodecState*>(mOpusState);
do {
if (packet) {
nsOggCodecState::ReleasePacket(packet);
}
packet = NextOggPacket(codecState);
} while (packet && codecState->IsHeader(packet));
if (!packet) {
mAudioQueue.Finish();
return false;
}
NS_ASSERTION(packet && packet->granulepos != -1,
"Must have packet with known granulepos");
nsAutoRef<ogg_packet> autoRelease(packet);
if (mVorbisState) {
DecodeVorbis(packet);
#ifdef MOZ_OPUS
} else if (mOpusState) {
DecodeOpus(packet);
#endif
}
if (packet->e_o_s) {
// We've encountered an end of bitstream packet, or we've hit the end of
// file while trying to decode, so inform the audio queue that there'll
// be no more samples.
mAudioQueue.Finish();
return false;
}
return true;
}
nsresult nsOggReader::DecodeTheora(ogg_packet* aPacket, PRInt64 aTimeThreshold)
{
NS_ASSERTION(aPacket->granulepos >= TheoraVersion(&mTheoraState->mInfo,3,2,1),
"Packets must have valid granulepos and packetno");
int ret = th_decode_packetin(mTheoraState->mCtx, aPacket, 0);
if (ret != 0 && ret != TH_DUPFRAME) {
return NS_ERROR_FAILURE;
}
PRInt64 time = mTheoraState->StartTime(aPacket->granulepos);
// Don't use the frame if it's outside the bounds of the presentation
// start time in the skeleton track. Note we still must submit the frame
// to the decoder (via th_decode_packetin), as the frames which are
// presentable may depend on this frame's data.
if (mSkeletonState && !mSkeletonState->IsPresentable(time)) {
return NS_OK;
}
PRInt64 endTime = mTheoraState->Time(aPacket->granulepos);
if (endTime < aTimeThreshold) {
// The end time of this frame is already before the current playback
// position. It will never be displayed, don't bother enqueing it.
return NS_OK;
}
if (ret == TH_DUPFRAME) {
VideoData* v = VideoData::CreateDuplicate(mPageOffset,
time,
endTime,
aPacket->granulepos);
mVideoQueue.Push(v);
} else if (ret == 0) {
th_ycbcr_buffer buffer;
ret = th_decode_ycbcr_out(mTheoraState->mCtx, buffer);
NS_ASSERTION(ret == 0, "th_decode_ycbcr_out failed");
bool isKeyframe = th_packet_iskeyframe(aPacket) == 1;
VideoData::YCbCrBuffer b;
for (PRUint32 i=0; i < 3; ++i) {
b.mPlanes[i].mData = buffer[i].data;
b.mPlanes[i].mHeight = buffer[i].height;
b.mPlanes[i].mWidth = buffer[i].width;
b.mPlanes[i].mStride = buffer[i].stride;
b.mPlanes[i].mOffset = b.mPlanes[i].mSkip = 0;
}
VideoData *v = VideoData::Create(mInfo,
mDecoder->GetImageContainer(),
mPageOffset,
time,
endTime,
b,
isKeyframe,
aPacket->granulepos,
mPicture);
if (!v) {
// There may be other reasons for this error, but for
// simplicity just assume the worst case: out of memory.
NS_WARNING("Failed to allocate memory for video frame");
return NS_ERROR_OUT_OF_MEMORY;
}
mVideoQueue.Push(v);
}
return NS_OK;
}
bool nsOggReader::DecodeVideoFrame(bool &aKeyframeSkip,
PRInt64 aTimeThreshold)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
// Record number of frames decoded and parsed. Automatically update the
// stats counters using the AutoNotifyDecoded stack-based class.
PRUint32 parsed = 0, decoded = 0;
nsMediaDecoder::AutoNotifyDecoded autoNotify(mDecoder, parsed, decoded);
// Read the next data packet. Skip any non-data packets we encounter.
ogg_packet* packet = 0;
do {
if (packet) {
nsOggCodecState::ReleasePacket(packet);
}
packet = NextOggPacket(mTheoraState);
} while (packet && mTheoraState->IsHeader(packet));
if (!packet) {
mVideoQueue.Finish();
return false;
}
nsAutoRef<ogg_packet> autoRelease(packet);
parsed++;
NS_ASSERTION(packet && packet->granulepos != -1,
"Must know first packet's granulepos");
bool eos = packet->e_o_s;
PRInt64 frameEndTime = mTheoraState->Time(packet->granulepos);
if (!aKeyframeSkip ||
(th_packet_iskeyframe(packet) && frameEndTime >= aTimeThreshold))
{
aKeyframeSkip = false;
nsresult res = DecodeTheora(packet, aTimeThreshold);
decoded++;
if (NS_FAILED(res)) {
return false;
}
}
if (eos) {
// We've encountered an end of bitstream packet. Inform the queue that
// there will be no more frames.
mVideoQueue.Finish();
return false;
}
return true;
}
PRInt64 nsOggReader::ReadOggPage(ogg_page* aPage)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
int ret = 0;
while((ret = ogg_sync_pageseek(&mOggState, aPage)) <= 0) {
if (ret < 0) {
// Lost page sync, have to skip up to next page.
mPageOffset += -ret;
continue;
}
// Returns a buffer that can be written too
// with the given size. This buffer is stored
// in the ogg synchronisation structure.
char* buffer = ogg_sync_buffer(&mOggState, 4096);
NS_ASSERTION(buffer, "ogg_sync_buffer failed");
// Read from the resource into the buffer
PRUint32 bytesRead = 0;
nsresult rv = mDecoder->GetResource()->Read(buffer, 4096, &bytesRead);
if (NS_FAILED(rv) || (bytesRead == 0 && ret == 0)) {
// End of file.
return -1;
}
mDecoder->NotifyBytesConsumed(bytesRead);
// Update the synchronisation layer with the number
// of bytes written to the buffer
ret = ogg_sync_wrote(&mOggState, bytesRead);
NS_ENSURE_TRUE(ret == 0, -1);
}
PRInt64 offset = mPageOffset;
mPageOffset += aPage->header_len + aPage->body_len;
return offset;
}
ogg_packet* nsOggReader::NextOggPacket(nsOggCodecState* aCodecState)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
if (!aCodecState || !aCodecState->mActive) {
return nullptr;
}
ogg_packet* packet;
while ((packet = aCodecState->PacketOut()) == nullptr) {
// The codec state does not have any buffered pages, so try to read another
// page from the channel.
ogg_page page;
if (ReadOggPage(&page) == -1) {
return nullptr;
}
PRUint32 serial = ogg_page_serialno(&page);
nsOggCodecState* codecState = nullptr;
mCodecStates.Get(serial, &codecState);
if (codecState && NS_FAILED(codecState->PageIn(&page))) {
return nullptr;
}
}
return packet;
}
// Returns an ogg page's checksum.
static ogg_uint32_t
GetChecksum(ogg_page* page)
{
if (page == 0 || page->header == 0 || page->header_len < 25) {
return 0;
}
const unsigned char* p = page->header + 22;
PRUint32 c = p[0] +
(p[1] << 8) +
(p[2] << 16) +
(p[3] << 24);
return c;
}
PRInt64 nsOggReader::RangeStartTime(PRInt64 aOffset)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
MediaResource* resource = mDecoder->GetResource();
NS_ENSURE_TRUE(resource != nullptr, 0);
nsresult res = resource->Seek(nsISeekableStream::NS_SEEK_SET, aOffset);
NS_ENSURE_SUCCESS(res, 0);
PRInt64 startTime = 0;
nsBuiltinDecoderReader::FindStartTime(startTime);
return startTime;
}
struct nsAutoOggSyncState {
nsAutoOggSyncState() {
ogg_sync_init(&mState);
}
~nsAutoOggSyncState() {
ogg_sync_clear(&mState);
}
ogg_sync_state mState;
};
PRInt64 nsOggReader::RangeEndTime(PRInt64 aEndOffset)
{
NS_ASSERTION(mDecoder->OnStateMachineThread() || mDecoder->OnDecodeThread(),
"Should be on state machine or decode thread.");
MediaResource* resource = mDecoder->GetResource();
NS_ENSURE_TRUE(resource != nullptr, -1);
PRInt64 position = resource->Tell();
PRInt64 endTime = RangeEndTime(0, aEndOffset, false);
nsresult res = resource->Seek(nsISeekableStream::NS_SEEK_SET, position);
NS_ENSURE_SUCCESS(res, -1);
return endTime;
}
PRInt64 nsOggReader::RangeEndTime(PRInt64 aStartOffset,
PRInt64 aEndOffset,
bool aCachedDataOnly)
{
MediaResource* resource = mDecoder->GetResource();
nsAutoOggSyncState sync;
// We need to find the last page which ends before aEndOffset that
// has a granulepos that we can convert to a timestamp. We do this by
// backing off from aEndOffset until we encounter a page on which we can
// interpret the granulepos. If while backing off we encounter a page which
// we've previously encountered before, we'll either backoff again if we
// haven't found an end time yet, or return the last end time found.
const int step = 5000;
const int maxOggPageSize = 65306;
PRInt64 readStartOffset = aEndOffset;
PRInt64 readLimitOffset = aEndOffset;
PRInt64 readHead = aEndOffset;
PRInt64 endTime = -1;
PRUint32 checksumAfterSeek = 0;
PRUint32 prevChecksumAfterSeek = 0;
bool mustBackOff = false;
while (true) {
ogg_page page;
int ret = ogg_sync_pageseek(&sync.mState, &page);
if (ret == 0) {
// We need more data if we've not encountered a page we've seen before,
// or we've read to the end of file.
if (mustBackOff || readHead == aEndOffset || readHead == aStartOffset) {
if (endTime != -1 || readStartOffset == 0) {
// We have encountered a page before, or we're at the end of file.
break;
}
mustBackOff = false;
prevChecksumAfterSeek = checksumAfterSeek;
checksumAfterSeek = 0;
ogg_sync_reset(&sync.mState);
readStartOffset = NS_MAX(static_cast<PRInt64>(0), readStartOffset - step);
// There's no point reading more than the maximum size of
// an Ogg page into data we've previously scanned. Any data
// between readLimitOffset and aEndOffset must be garbage
// and we can ignore it thereafter.
readLimitOffset = NS_MIN(readLimitOffset,
readStartOffset + maxOggPageSize);
readHead = NS_MAX(aStartOffset, readStartOffset);
}
PRInt64 limit = NS_MIN(static_cast<PRInt64>(PR_UINT32_MAX),
aEndOffset - readHead);
limit = NS_MAX(static_cast<PRInt64>(0), limit);
limit = NS_MIN(limit, static_cast<PRInt64>(step));
PRUint32 bytesToRead = static_cast<PRUint32>(limit);
PRUint32 bytesRead = 0;
char* buffer = ogg_sync_buffer(&sync.mState, bytesToRead);
NS_ASSERTION(buffer, "Must have buffer");
nsresult res;
if (aCachedDataOnly) {
res = resource->ReadFromCache(buffer, readHead, bytesToRead);
NS_ENSURE_SUCCESS(res, -1);
bytesRead = bytesToRead;
} else {
NS_ASSERTION(readHead < aEndOffset,
"resource pos must be before range end");
res = resource->Seek(nsISeekableStream::NS_SEEK_SET, readHead);
NS_ENSURE_SUCCESS(res, -1);
res = resource->Read(buffer, bytesToRead, &bytesRead);
NS_ENSURE_SUCCESS(res, -1);
}
readHead += bytesRead;
if (readHead > readLimitOffset) {
mustBackOff = true;
}
// Update the synchronisation layer with the number
// of bytes written to the buffer
ret = ogg_sync_wrote(&sync.mState, bytesRead);
if (ret != 0) {
endTime = -1;
break;
}
continue;
}
if (ret < 0 || ogg_page_granulepos(&page) < 0) {
continue;
}
PRUint32 checksum = GetChecksum(&page);
if (checksumAfterSeek == 0) {
// This is the first page we've decoded after a backoff/seek. Remember
// the page checksum. If we backoff further and encounter this page
// again, we'll know that we won't find a page with an end time after
// this one, so we'll know to back off again.
checksumAfterSeek = checksum;
}
if (checksum == prevChecksumAfterSeek) {
// This page has the same checksum as the first page we encountered
// after the last backoff/seek. Since we've already scanned after this
// page and failed to find an end time, we may as well backoff again and
// try to find an end time from an earlier page.
mustBackOff = true;
continue;
}
PRInt64 granulepos = ogg_page_granulepos(&page);
int serial = ogg_page_serialno(&page);
nsOggCodecState* codecState = nullptr;
mCodecStates.Get(serial, &codecState);
if (!codecState) {
// This page is from a bitstream which we haven't encountered yet.
// It's probably from a new "link" in a "chained" ogg. Don't
// bother even trying to find a duration...
endTime = -1;
break;
}
PRInt64 t = codecState->Time(granulepos);
if (t != -1) {
endTime = t;
}
}
return endTime;
}
nsresult nsOggReader::GetSeekRanges(nsTArray<SeekRange>& aRanges)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
nsTArray<MediaByteRange> cached;
nsresult res = mDecoder->GetResource()->GetCachedRanges(cached);
NS_ENSURE_SUCCESS(res, res);
for (PRUint32 index = 0; index < cached.Length(); index++) {
MediaByteRange& range = cached[index];
PRInt64 startTime = -1;
PRInt64 endTime = -1;
if (NS_FAILED(ResetDecode())) {
return NS_ERROR_FAILURE;
}
PRInt64 startOffset = range.mStart;
PRInt64 endOffset = range.mEnd;
startTime = RangeStartTime(startOffset);
if (startTime != -1 &&
((endTime = RangeEndTime(endOffset)) != -1))
{
NS_ASSERTION(startTime < endTime,
"Start time must be before end time");
aRanges.AppendElement(SeekRange(startOffset,
endOffset,
startTime,
endTime));
}
}
if (NS_FAILED(ResetDecode())) {
return NS_ERROR_FAILURE;
}
return NS_OK;
}
nsOggReader::SeekRange
nsOggReader::SelectSeekRange(const nsTArray<SeekRange>& ranges,
PRInt64 aTarget,
PRInt64 aStartTime,
PRInt64 aEndTime,
bool aExact)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
PRInt64 so = 0;
PRInt64 eo = mDecoder->GetResource()->GetLength();
PRInt64 st = aStartTime;
PRInt64 et = aEndTime;
for (PRUint32 i = 0; i < ranges.Length(); i++) {
const SeekRange &r = ranges[i];
if (r.mTimeStart < aTarget) {
so = r.mOffsetStart;
st = r.mTimeStart;
}
if (r.mTimeEnd >= aTarget && r.mTimeEnd < et) {
eo = r.mOffsetEnd;
et = r.mTimeEnd;
}
if (r.mTimeStart < aTarget && aTarget <= r.mTimeEnd) {
// Target lies exactly in this range.
return ranges[i];
}
}
if (aExact || eo == -1) {
return SeekRange();
}
return SeekRange(so, eo, st, et);
}
nsOggReader::IndexedSeekResult nsOggReader::RollbackIndexedSeek(PRInt64 aOffset)
{
mSkeletonState->Deactivate();
MediaResource* resource = mDecoder->GetResource();
NS_ENSURE_TRUE(resource != nullptr, SEEK_FATAL_ERROR);
nsresult res = resource->Seek(nsISeekableStream::NS_SEEK_SET, aOffset);
NS_ENSURE_SUCCESS(res, SEEK_FATAL_ERROR);
return SEEK_INDEX_FAIL;
}
nsOggReader::IndexedSeekResult nsOggReader::SeekToKeyframeUsingIndex(PRInt64 aTarget)
{
MediaResource* resource = mDecoder->GetResource();
NS_ENSURE_TRUE(resource != nullptr, SEEK_FATAL_ERROR);
if (!HasSkeleton() || !mSkeletonState->HasIndex()) {
return SEEK_INDEX_FAIL;
}
// We have an index from the Skeleton track, try to use it to seek.
nsAutoTArray<PRUint32, 2> tracks;
BuildSerialList(tracks);
nsSkeletonState::nsSeekTarget keyframe;
if (NS_FAILED(mSkeletonState->IndexedSeekTarget(aTarget,
tracks,
keyframe)))
{
// Could not locate a keypoint for the target in the index.
return SEEK_INDEX_FAIL;
}
// Remember original resource read cursor position so we can rollback on failure.
PRInt64 tell = resource->Tell();
// Seek to the keypoint returned by the index.
if (keyframe.mKeyPoint.mOffset > resource->GetLength() ||
keyframe.mKeyPoint.mOffset < 0)
{
// Index must be invalid.
return RollbackIndexedSeek(tell);
}
LOG(PR_LOG_DEBUG, ("Seeking using index to keyframe at offset %lld\n",
keyframe.mKeyPoint.mOffset));
nsresult res = resource->Seek(nsISeekableStream::NS_SEEK_SET,
keyframe.mKeyPoint.mOffset);
NS_ENSURE_SUCCESS(res, SEEK_FATAL_ERROR);
mPageOffset = keyframe.mKeyPoint.mOffset;
// We've moved the read set, so reset decode.
res = ResetDecode();
NS_ENSURE_SUCCESS(res, SEEK_FATAL_ERROR);
// Check that the page the index thinks is exactly here is actually exactly
// here. If not, the index is invalid.
ogg_page page;
int skippedBytes = 0;
PageSyncResult syncres = PageSync(resource,
&mOggState,
false,
mPageOffset,
resource->GetLength(),
&page,
skippedBytes);
NS_ENSURE_TRUE(syncres != PAGE_SYNC_ERROR, SEEK_FATAL_ERROR);
if (syncres != PAGE_SYNC_OK || skippedBytes != 0) {
LOG(PR_LOG_DEBUG, ("Indexed-seek failure: Ogg Skeleton Index is invalid "
"or sync error after seek"));
return RollbackIndexedSeek(tell);
}
PRUint32 serial = ogg_page_serialno(&page);
if (serial != keyframe.mSerial) {
// Serialno of page at offset isn't what the index told us to expect.
// Assume the index is invalid.
return RollbackIndexedSeek(tell);
}
nsOggCodecState* codecState = nullptr;
mCodecStates.Get(serial, &codecState);
if (codecState &&
codecState->mActive &&
ogg_stream_pagein(&codecState->mState, &page) != 0)
{
// Couldn't insert page into the ogg resource, or somehow the resource
// is no longer active.
return RollbackIndexedSeek(tell);
}
mPageOffset = keyframe.mKeyPoint.mOffset + page.header_len + page.body_len;
return SEEK_OK;
}
nsresult nsOggReader::SeekInBufferedRange(PRInt64 aTarget,
PRInt64 aAdjustedTarget,
PRInt64 aStartTime,
PRInt64 aEndTime,
const nsTArray<SeekRange>& aRanges,
const SeekRange& aRange)
{
LOG(PR_LOG_DEBUG, ("%p Seeking in buffered data to %lld using bisection search", mDecoder, aTarget));
nsresult res = NS_OK;
if (HasVideo() || aAdjustedTarget >= aTarget) {
// We know the exact byte range in which the target must lie. It must
// be buffered in the media cache. Seek there.
nsresult res = SeekBisection(aTarget, aRange, 0);
if (NS_FAILED(res) || !HasVideo()) {
return res;
}
// We have an active Theora bitstream. Decode the next Theora frame, and
// extract its keyframe's time.
bool eof;
do {
bool skip = false;
eof = !DecodeVideoFrame(skip, 0);
{
ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
if (mDecoder->GetDecodeState() == nsBuiltinDecoderStateMachine::DECODER_STATE_SHUTDOWN) {
return NS_ERROR_FAILURE;
}
}
} while (!eof &&
mVideoQueue.GetSize() == 0);
VideoData* video = mVideoQueue.PeekFront();
if (video && !video->mKeyframe) {
// First decoded frame isn't a keyframe, seek back to previous keyframe,
// otherwise we'll get visual artifacts.
NS_ASSERTION(video->mTimecode != -1, "Must have a granulepos");
int shift = mTheoraState->mInfo.keyframe_granule_shift;
PRInt64 keyframeGranulepos = (video->mTimecode >> shift) << shift;
PRInt64 keyframeTime = mTheoraState->StartTime(keyframeGranulepos);
SEEK_LOG(PR_LOG_DEBUG, ("Keyframe for %lld is at %lld, seeking back to it",
video->mTime, keyframeTime));
aAdjustedTarget = NS_MIN(aAdjustedTarget, keyframeTime);
}
}
if (aAdjustedTarget < aTarget) {
SeekRange k = SelectSeekRange(aRanges,
aAdjustedTarget,
aStartTime,
aEndTime,
false);
res = SeekBisection(aAdjustedTarget, k, SEEK_FUZZ_USECS);
}
return res;
}
nsresult nsOggReader::SeekInUnbuffered(PRInt64 aTarget,
PRInt64 aStartTime,
PRInt64 aEndTime,
const nsTArray<SeekRange>& aRanges)
{
LOG(PR_LOG_DEBUG, ("%p Seeking in unbuffered data to %lld using bisection search", mDecoder, aTarget));
// If we've got an active Theora bitstream, determine the maximum possible
// time in usecs which a keyframe could be before a given interframe. We
// subtract this from our seek target, seek to the new target, and then
// will decode forward to the original seek target. We should encounter a
// keyframe in that interval. This prevents us from needing to run two
// bisections; one for the seek target frame, and another to find its
// keyframe. It's usually faster to just download this extra data, rather
// tham perform two bisections to find the seek target's keyframe. We
// don't do this offsetting when seeking in a buffered range,
// as the extra decoding causes a noticeable speed hit when all the data
// is buffered (compared to just doing a bisection to exactly find the
// keyframe).
PRInt64 keyframeOffsetMs = 0;
if (HasVideo() && mTheoraState) {
keyframeOffsetMs = mTheoraState->MaxKeyframeOffset();
}
// Add in the Opus pre-roll if necessary, as well.
if (HasAudio() && mOpusState) {
keyframeOffsetMs = NS_MAX(keyframeOffsetMs, SEEK_OPUS_PREROLL);
}
PRInt64 seekTarget = NS_MAX(aStartTime, aTarget - keyframeOffsetMs);
// Minimize the bisection search space using the known timestamps from the
// buffered ranges.
SeekRange k = SelectSeekRange(aRanges, seekTarget, aStartTime, aEndTime, false);
return SeekBisection(seekTarget, k, SEEK_FUZZ_USECS);
}
nsresult nsOggReader::Seek(PRInt64 aTarget,
PRInt64 aStartTime,
PRInt64 aEndTime,
PRInt64 aCurrentTime)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
LOG(PR_LOG_DEBUG, ("%p About to seek to %lld", mDecoder, aTarget));
nsresult res;
MediaResource* resource = mDecoder->GetResource();
NS_ENSURE_TRUE(resource != nullptr, NS_ERROR_FAILURE);
PRInt64 adjustedTarget = aTarget;
if (HasAudio() && mOpusState){
adjustedTarget = NS_MAX(aStartTime, aTarget - SEEK_OPUS_PREROLL);
}
if (adjustedTarget == aStartTime) {
// We've seeked to the media start. Just seek to the offset of the first
// content page.
res = resource->Seek(nsISeekableStream::NS_SEEK_SET, 0);
NS_ENSURE_SUCCESS(res,res);
mPageOffset = 0;
res = ResetDecode(true);
NS_ENSURE_SUCCESS(res,res);
NS_ASSERTION(aStartTime != -1, "mStartTime should be known");
{
ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
mDecoder->UpdatePlaybackPosition(aStartTime);
}
} else {
// TODO: This may seek back unnecessarily far in the video, but we don't
// have a way of asking Skeleton to seek to a different target for each
// stream yet. Using adjustedTarget here is at least correct, if slow.
IndexedSeekResult sres = SeekToKeyframeUsingIndex(adjustedTarget);
NS_ENSURE_TRUE(sres != SEEK_FATAL_ERROR, NS_ERROR_FAILURE);
if (sres == SEEK_INDEX_FAIL) {
// No index or other non-fatal index-related failure. Try to seek
// using a bisection search. Determine the already downloaded data
// in the media cache, so we can try to seek in the cached data first.
nsAutoTArray<SeekRange, 16> ranges;
res = GetSeekRanges(ranges);
NS_ENSURE_SUCCESS(res,res);
// Figure out if the seek target lies in a buffered range.
SeekRange r = SelectSeekRange(ranges, aTarget, aStartTime, aEndTime, true);
if (!r.IsNull()) {
// We know the buffered range in which the seek target lies, do a
// bisection search in that buffered range.
res = SeekInBufferedRange(aTarget, adjustedTarget, aStartTime, aEndTime, ranges, r);
NS_ENSURE_SUCCESS(res,res);
} else {
// The target doesn't lie in a buffered range. Perform a bisection
// search over the whole media, using the known buffered ranges to
// reduce the search space.
res = SeekInUnbuffered(aTarget, aStartTime, aEndTime, ranges);
NS_ENSURE_SUCCESS(res,res);
}
}
}
// The decode position must now be either close to the seek target, or
// we've seeked to before the keyframe before the seek target. Decode
// forward to the seek target frame.
return DecodeToTarget(aTarget);
}
// Reads a page from the media resource.
static PageSyncResult
PageSync(MediaResource* aResource,
ogg_sync_state* aState,
bool aCachedDataOnly,
PRInt64 aOffset,
PRInt64 aEndOffset,
ogg_page* aPage,
int& aSkippedBytes)
{
aSkippedBytes = 0;
// Sync to the next page.
int ret = 0;
PRUint32 bytesRead = 0;
PRInt64 readHead = aOffset;
while (ret <= 0) {
ret = ogg_sync_pageseek(aState, aPage);
if (ret == 0) {
char* buffer = ogg_sync_buffer(aState, PAGE_STEP);
NS_ASSERTION(buffer, "Must have a buffer");
// Read from the file into the buffer
PRInt64 bytesToRead = NS_MIN(static_cast<PRInt64>(PAGE_STEP),
aEndOffset - readHead);
NS_ASSERTION(bytesToRead <= PR_UINT32_MAX, "bytesToRead range check");
if (bytesToRead <= 0) {
return PAGE_SYNC_END_OF_RANGE;
}
nsresult rv = NS_OK;
if (aCachedDataOnly) {
rv = aResource->ReadFromCache(buffer, readHead,
static_cast<PRUint32>(bytesToRead));
NS_ENSURE_SUCCESS(rv,PAGE_SYNC_ERROR);
bytesRead = static_cast<PRUint32>(bytesToRead);
} else {
rv = aResource->Seek(nsISeekableStream::NS_SEEK_SET, readHead);
NS_ENSURE_SUCCESS(rv,PAGE_SYNC_ERROR);
rv = aResource->Read(buffer,
static_cast<PRUint32>(bytesToRead),
&bytesRead);
NS_ENSURE_SUCCESS(rv,PAGE_SYNC_ERROR);
}
if (bytesRead == 0 && NS_SUCCEEDED(rv)) {
// End of file.
return PAGE_SYNC_END_OF_RANGE;
}
readHead += bytesRead;
// Update the synchronisation layer with the number
// of bytes written to the buffer
ret = ogg_sync_wrote(aState, bytesRead);
NS_ENSURE_TRUE(ret == 0, PAGE_SYNC_ERROR);
continue;
}
if (ret < 0) {
NS_ASSERTION(aSkippedBytes >= 0, "Offset >= 0");
aSkippedBytes += -ret;
NS_ASSERTION(aSkippedBytes >= 0, "Offset >= 0");
continue;
}
}
return PAGE_SYNC_OK;
}
nsresult nsOggReader::SeekBisection(PRInt64 aTarget,
const SeekRange& aRange,
PRUint32 aFuzz)
{
NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
nsresult res;
MediaResource* resource = mDecoder->GetResource();
if (aTarget == aRange.mTimeStart) {
if (NS_FAILED(ResetDecode())) {
return NS_ERROR_FAILURE;
}
res = resource->Seek(nsISeekableStream::NS_SEEK_SET, 0);
NS_ENSURE_SUCCESS(res,res);
mPageOffset = 0;
return NS_OK;
}
// Bisection search, find start offset of last page with end time less than
// the seek target.
ogg_int64_t startOffset = aRange.mOffsetStart;
ogg_int64_t startTime = aRange.mTimeStart;
ogg_int64_t startLength = 0; // Length of the page at startOffset.
ogg_int64_t endOffset = aRange.mOffsetEnd;
ogg_int64_t endTime = aRange.mTimeEnd;
ogg_int64_t seekTarget = aTarget;
PRInt64 seekLowerBound = NS_MAX(static_cast<PRInt64>(0), aTarget - aFuzz);
int hops = 0;
DebugOnly<ogg_int64_t> previousGuess = -1;
int backsteps = 0;
const int maxBackStep = 10;
NS_ASSERTION(static_cast<PRUint64>(PAGE_STEP) * pow(2.0, maxBackStep) < PR_INT32_MAX,
"Backstep calculation must not overflow");
// Seek via bisection search. Loop until we find the offset where the page
// before the offset is before the seek target, and the page after the offset
// is after the seek target.
while (true) {
ogg_int64_t duration = 0;
double target = 0;
ogg_int64_t interval = 0;
ogg_int64_t guess = 0;
ogg_page page;
int skippedBytes = 0;
ogg_int64_t pageOffset = 0;
ogg_int64_t pageLength = 0;
ogg_int64_t granuleTime = -1;
bool mustBackoff = false;
// Guess where we should bisect to, based on the bit rate and the time
// remaining in the interval. Loop until we can determine the time at
// the guess offset.
while (true) {
// Discard any previously buffered packets/pages.
if (NS_FAILED(ResetDecode())) {
return NS_ERROR_FAILURE;
}
interval = endOffset - startOffset - startLength;
if (interval == 0) {
// Our interval is empty, we've found the optimal seek point, as the
// page at the start offset is before the seek target, and the page
// at the end offset is after the seek target.
SEEK_LOG(PR_LOG_DEBUG, ("Interval narrowed, terminating bisection."));
break;
}
// Guess bisection point.
duration = endTime - startTime;
target = (double)(seekTarget - startTime) / (double)duration;
guess = startOffset + startLength +
static_cast<ogg_int64_t>((double)interval * target);
guess = NS_MIN(guess, endOffset - PAGE_STEP);
if (mustBackoff) {
// We previously failed to determine the time at the guess offset,
// probably because we ran out of data to decode. This usually happens
// when we guess very close to the end offset. So reduce the guess
// offset using an exponential backoff until we determine the time.
SEEK_LOG(PR_LOG_DEBUG, ("Backing off %d bytes, backsteps=%d",
static_cast<PRInt32>(PAGE_STEP * pow(2.0, backsteps)), backsteps));
guess -= PAGE_STEP * static_cast<ogg_int64_t>(pow(2.0, backsteps));
if (guess <= startOffset) {
// We've tried to backoff to before the start offset of our seek
// range. This means we couldn't find a seek termination position
// near the end of the seek range, so just set the seek termination
// condition, and break out of the bisection loop. We'll begin
// decoding from the start of the seek range.
interval = 0;
break;
}
backsteps = NS_MIN(backsteps + 1, maxBackStep);
// We reset mustBackoff. If we still need to backoff further, it will
// be set to true again.
mustBackoff = false;
} else {
backsteps = 0;
}
guess = NS_MAX(guess, startOffset + startLength);
SEEK_LOG(PR_LOG_DEBUG, ("Seek loop start[o=%lld..%lld t=%lld] "
"end[o=%lld t=%lld] "
"interval=%lld target=%lf guess=%lld",
startOffset, (startOffset+startLength), startTime,
endOffset, endTime, interval, target, guess));
NS_ASSERTION(guess >= startOffset + startLength, "Guess must be after range start");
NS_ASSERTION(guess < endOffset, "Guess must be before range end");
NS_ASSERTION(guess != previousGuess, "Guess should be different to previous");
previousGuess = guess;
hops++;
// Locate the next page after our seek guess, and then figure out the
// granule time of the audio and video bitstreams there. We can then
// make a bisection decision based on our location in the media.
PageSyncResult res = PageSync(resource,
&mOggState,
false,
guess,
endOffset,
&page,
skippedBytes);
NS_ENSURE_TRUE(res != PAGE_SYNC_ERROR, NS_ERROR_FAILURE);
// We've located a page of length |ret| at |guess + skippedBytes|.
// Remember where the page is located.
pageOffset = guess + skippedBytes;
pageLength = page.header_len + page.body_len;
mPageOffset = pageOffset + pageLength;
if (res == PAGE_SYNC_END_OF_RANGE) {
// Our guess was too close to the end, we've ended up reading the end
// page. Backoff exponentially from the end point, in case the last
// page/frame/sample is huge.
mustBackoff = true;
SEEK_LOG(PR_LOG_DEBUG, ("Hit the end of range, backing off"));
continue;
}
// Read pages until we can determine the granule time of the audio and
// video bitstream.
ogg_int64_t audioTime = -1;
ogg_int64_t videoTime = -1;
do {
// Add the page to its codec state, determine its granule time.
PRUint32 serial = ogg_page_serialno(&page);
nsOggCodecState* codecState = nullptr;
mCodecStates.Get(serial, &codecState);
if (codecState && codecState->mActive) {
int ret = ogg_stream_pagein(&codecState->mState, &page);
NS_ENSURE_TRUE(ret == 0, NS_ERROR_FAILURE);
}
ogg_int64_t granulepos = ogg_page_granulepos(&page);
if (HasAudio() && granulepos > 0 && audioTime == -1) {
if (mVorbisState && serial == mVorbisState->mSerial) {
audioTime = mVorbisState->Time(granulepos);
#ifdef MOZ_OPUS
} else if (mOpusState && serial == mOpusState->mSerial) {
audioTime = mOpusState->Time(granulepos);
#endif
}
}
if (HasVideo() &&
granulepos > 0 &&
serial == mTheoraState->mSerial &&
videoTime == -1) {
videoTime = mTheoraState->StartTime(granulepos);
}
if (mPageOffset == endOffset) {
// Hit end of readable data.
break;
}
if (ReadOggPage(&page) == -1) {
break;
}
} while ((HasAudio() && audioTime == -1) ||
(HasVideo() && videoTime == -1));
NS_ASSERTION(mPageOffset <= endOffset, "Page read cursor should be inside range");
if ((HasAudio() && audioTime == -1) ||
(HasVideo() && videoTime == -1))
{
// We don't have timestamps for all active tracks...
if (pageOffset == startOffset + startLength && mPageOffset == endOffset) {
// We read the entire interval without finding timestamps for all
// active tracks. We know the interval start offset is before the seek
// target, and the interval end is after the seek target, and we can't
// terminate inside the interval, so we terminate the seek at the
// start of the interval.
interval = 0;
break;
}
// We should backoff; cause the guess to back off from the end, so
// that we've got more room to capture.
mustBackoff = true;
continue;
}
// We've found appropriate time stamps here. Proceed to bisect
// the search space.
granuleTime = NS_MAX(audioTime, videoTime);
NS_ASSERTION(granuleTime > 0, "Must get a granuletime");
break;
} // End of "until we determine time at guess offset" loop.
if (interval == 0) {
// Seek termination condition; we've found the page boundary of the
// last page before the target, and the first page after the target.
SEEK_LOG(PR_LOG_DEBUG, ("Terminating seek at offset=%lld", startOffset));
NS_ASSERTION(startTime < aTarget, "Start time must always be less than target");
res = resource->Seek(nsISeekableStream::NS_SEEK_SET, startOffset);
NS_ENSURE_SUCCESS(res,res);
mPageOffset = startOffset;
if (NS_FAILED(ResetDecode())) {
return NS_ERROR_FAILURE;
}
break;
}
SEEK_LOG(PR_LOG_DEBUG, ("Time at offset %lld is %lld", guess, granuleTime));
if (granuleTime < seekTarget && granuleTime > seekLowerBound) {
// We're within the fuzzy region in which we want to terminate the search.
res = resource->Seek(nsISeekableStream::NS_SEEK_SET, pageOffset);
NS_ENSURE_SUCCESS(res,res);
mPageOffset = pageOffset;
if (NS_FAILED(ResetDecode())) {
return NS_ERROR_FAILURE;
}
SEEK_LOG(PR_LOG_DEBUG, ("Terminating seek at offset=%lld", mPageOffset));
break;
}
if (granuleTime >= seekTarget) {
// We've landed after the seek target.
NS_ASSERTION(pageOffset < endOffset, "offset_end must decrease");
endOffset = pageOffset;
endTime = granuleTime;
} else if (granuleTime < seekTarget) {
// Landed before seek target.
NS_ASSERTION(pageOffset >= startOffset + startLength,
"Bisection point should be at or after end of first page in interval");
startOffset = pageOffset;
startLength = pageLength;
startTime = granuleTime;
}
NS_ASSERTION(startTime < seekTarget, "Must be before seek target");
NS_ASSERTION(endTime >= seekTarget, "End must be after seek target");
}
SEEK_LOG(PR_LOG_DEBUG, ("Seek complete in %d bisections.", hops));
return NS_OK;
}
nsresult nsOggReader::GetBuffered(nsTimeRanges* aBuffered, PRInt64 aStartTime)
{
// HasAudio and HasVideo are not used here as they take a lock and cause
// a deadlock. Accessing mInfo doesn't require a lock - it doesn't change
// after metadata is read.
if (!mInfo.mHasVideo && !mInfo.mHasAudio) {
// No need to search through the file if there are no audio or video tracks
return NS_OK;
}
MediaResource* resource = mDecoder->GetResource();
nsTArray<MediaByteRange> ranges;
nsresult res = resource->GetCachedRanges(ranges);
NS_ENSURE_SUCCESS(res, res);
// Traverse across the buffered byte ranges, determining the time ranges
// they contain. MediaResource::GetNextCachedData(offset) returns -1 when
// offset is after the end of the media resource, or there's no more cached
// data after the offset. This loop will run until we've checked every
// buffered range in the media, in increasing order of offset.
nsAutoOggSyncState sync;
for (PRUint32 index = 0; index < ranges.Length(); index++) {
// Ensure the offsets are after the header pages.
PRInt64 startOffset = ranges[index].mStart;
PRInt64 endOffset = ranges[index].mEnd;
// Because the granulepos time is actually the end time of the page,
// we special-case (startOffset == 0) so that the first
// buffered range always appears to be buffered from the media start
// time, rather than from the end-time of the first page.
PRInt64 startTime = (startOffset == 0) ? aStartTime : -1;
// Find the start time of the range. Read pages until we find one with a
// granulepos which we can convert into a timestamp to use as the time of
// the start of the buffered range.
ogg_sync_reset(&sync.mState);
while (startTime == -1) {
ogg_page page;
PRInt32 discard;
PageSyncResult res = PageSync(resource,
&sync.mState,
true,
startOffset,
endOffset,
&page,
discard);
if (res == PAGE_SYNC_ERROR) {
return NS_ERROR_FAILURE;
} else if (res == PAGE_SYNC_END_OF_RANGE) {
// Hit the end of range without reading a page, give up trying to
// find a start time for this buffered range, skip onto the next one.
break;
}
PRInt64 granulepos = ogg_page_granulepos(&page);
if (granulepos == -1) {
// Page doesn't have an end time, advance to the next page
// until we find one.
startOffset += page.header_len + page.body_len;
continue;
}
PRUint32 serial = ogg_page_serialno(&page);
if (mVorbisState && serial == mVorbisSerial) {
startTime = nsVorbisState::Time(&mVorbisInfo, granulepos);
NS_ASSERTION(startTime > 0, "Must have positive start time");
}
else if (mOpusState && serial == mOpusSerial) {
startTime = nsOpusState::Time(mOpusPreSkip, granulepos);
NS_ASSERTION(startTime > 0, "Must have positive start time");
}
else if (mTheoraState && serial == mTheoraSerial) {
startTime = nsTheoraState::Time(&mTheoraInfo, granulepos);
NS_ASSERTION(startTime > 0, "Must have positive start time");
}
else if (IsKnownStream(serial)) {
// Stream is not the theora or vorbis stream we're playing,
// but is one that we have header data for.
startOffset += page.header_len + page.body_len;
continue;
}
else {
// Page is for a stream we don't know about (possibly a chained
// ogg), return OK to abort the finding any further ranges. This
// prevents us searching through the rest of the media when we
// may not be able to extract timestamps from it.
return NS_OK;
}
}
if (startTime != -1) {
// We were able to find a start time for that range, see if we can
// find an end time.
PRInt64 endTime = RangeEndTime(startOffset, endOffset, true);
if (endTime != -1) {
aBuffered->Add((startTime - aStartTime) / static_cast<double>(USECS_PER_S),
(endTime - aStartTime) / static_cast<double>(USECS_PER_S));
}
}
}
return NS_OK;
}
bool nsOggReader::IsKnownStream(PRUint32 aSerial)
{
for (PRUint32 i = 0; i < mKnownStreams.Length(); i++) {
PRUint32 serial = mKnownStreams[i];
if (serial == aSerial) {
return true;
}
}
return false;
}
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