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pjs/content/media/nsBuiltinDecoderStateMachin...

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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: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: ML 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla code.
*
* The Initial Developer of the Original Code is the Mozilla Corporation.
* Portions created by the Initial Developer are Copyright (C) 2007
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Double <chris.double@double.co.nz>
* Chris Pearce <chris@pearce.org.nz>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <limits>
#include "nsAudioStream.h"
#include "nsTArray.h"
#include "nsBuiltinDecoder.h"
#include "nsBuiltinDecoderReader.h"
#include "nsBuiltinDecoderStateMachine.h"
#include "mozilla/mozalloc.h"
#include "VideoUtils.h"
using namespace mozilla;
using namespace mozilla::layers;
#ifdef PR_LOGGING
extern PRLogModuleInfo* gBuiltinDecoderLog;
#define LOG(type, msg) PR_LOG(gBuiltinDecoderLog, type, msg)
#else
#define LOG(type, msg)
#endif
// Wait this number of seconds when buffering, then leave and play
// as best as we can if the required amount of data hasn't been
// retrieved.
#define BUFFERING_WAIT 30
// The amount of data to retrieve during buffering is computed based
// on the download rate. BUFFERING_MIN_RATE is the minimum download
// rate to be used in that calculation to help avoid constant buffering
// attempts at a time when the average download rate has not stabilised.
#define BUFFERING_MIN_RATE 50000
#define BUFFERING_RATE(x) ((x)< BUFFERING_MIN_RATE ? BUFFERING_MIN_RATE : (x))
// If audio queue has less than this many ms of decoded audio, we won't risk
// trying to decode the video, we'll skip decoding video up to the next
// keyframe.
//
// Also if the decode catches up with the end of the downloaded data,
// we'll only go into BUFFERING state if we've got audio and have queued
// less than LOW_AUDIO_MS of audio, or if we've got video and have queued
// less than LOW_VIDEO_FRAMES frames.
static const PRUint32 LOW_AUDIO_MS = 300;
// If more than this many ms of decoded audio is queued, we'll hold off
// decoding more audio.
const unsigned AMPLE_AUDIO_MS = 2000;
// If we have fewer than LOW_VIDEO_FRAMES decoded frames, and
// we're not "pumping video", we'll skip the video up to the next keyframe
// which is at or after the current playback position.
//
// Also if the decode catches up with the end of the downloaded data,
// we'll only go into BUFFERING state if we've got audio and have queued
// less than LOW_AUDIO_MS of audio, or if we've got video and have queued
// less than LOW_VIDEO_FRAMES frames.
static const PRUint32 LOW_VIDEO_FRAMES = 1;
// Arbitrary "frame duration" when playing only audio.
static const int AUDIO_DURATION_MS = 40;
nsBuiltinDecoderStateMachine::nsBuiltinDecoderStateMachine(nsBuiltinDecoder* aDecoder,
nsBuiltinDecoderReader* aReader) :
mDecoder(aDecoder),
mState(DECODER_STATE_DECODING_METADATA),
mAudioMonitor("media.audiostream"),
mCbCrSize(0),
mPlayDuration(0),
mBufferingEndOffset(0),
mStartTime(-1),
mEndTime(-1),
mSeekTime(0),
mReader(aReader),
mCurrentFrameTime(0),
mAudioStartTime(-1),
mAudioEndTime(-1),
mVideoFrameEndTime(-1),
mVolume(1.0),
mSeekable(PR_TRUE),
mPositionChangeQueued(PR_FALSE),
mAudioCompleted(PR_FALSE),
mBufferExhausted(PR_FALSE),
mGotDurationFromHeader(PR_FALSE),
mStopDecodeThreads(PR_TRUE)
{
MOZ_COUNT_CTOR(nsBuiltinDecoderStateMachine);
}
nsBuiltinDecoderStateMachine::~nsBuiltinDecoderStateMachine()
{
MOZ_COUNT_DTOR(nsBuiltinDecoderStateMachine);
}
PRBool nsBuiltinDecoderStateMachine::HasFutureAudio() const {
mDecoder->GetMonitor().AssertCurrentThreadIn();
PRBool aboveLowAudioThreshold = PR_FALSE;
if (mAudioEndTime != -1) {
aboveLowAudioThreshold = mAudioEndTime - mCurrentFrameTime + mStartTime > LOW_AUDIO_MS;
}
return HasAudio() &&
!mAudioCompleted &&
(mReader->mAudioQueue.GetSize() > 0 || aboveLowAudioThreshold);
}
PRBool nsBuiltinDecoderStateMachine::HaveNextFrameData() const {
return ((!HasAudio() || mReader->mAudioQueue.AtEndOfStream()) &&
mReader->mVideoQueue.GetSize() > 0) ||
HasFutureAudio();
}
void nsBuiltinDecoderStateMachine::DecodeLoop()
{
NS_ASSERTION(OnDecodeThread(), "Should be on decode thread.");
PRBool videoPlaying = PR_FALSE;
PRBool audioPlaying = PR_FALSE;
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
videoPlaying = HasVideo();
audioPlaying = HasAudio();
}
// We want to "pump" the decode until we've got a few frames/samples decoded
// before we consider whether decode is falling behind.
PRBool audioPump = PR_TRUE;
PRBool videoPump = PR_TRUE;
// If the video decode is falling behind the audio, we'll start dropping the
// inter-frames up until the next keyframe which is at or before the current
// playback position. skipToNextKeyframe is PR_TRUE if we're currently
// skipping up to the next keyframe.
PRBool skipToNextKeyframe = PR_FALSE;
// Once we've decoded more than videoPumpThreshold video frames, we'll
// no longer be considered to be "pumping video".
const unsigned videoPumpThreshold = 5;
// If we've got more than videoWaitThreshold decoded video frames waiting in
// the video queue, we will not decode any more video frames until they've
// been consumed by the play state machine thread.
const unsigned videoWaitThreshold = 10;
// After the audio decode fills with more than audioPumpThresholdMs ms
// of decoded audio, we'll start to check whether the audio or video decode
// is falling behind.
const unsigned audioPumpThresholdMs = LOW_AUDIO_MS * 2;
// Main decode loop.
while (videoPlaying || audioPlaying) {
PRBool audioWait = !audioPlaying;
PRBool videoWait = !videoPlaying;
{
// Wait for more data to download if we've exhausted all our
// buffered data.
MonitorAutoEnter mon(mDecoder->GetMonitor());
while (!mStopDecodeThreads &&
mBufferExhausted &&
mState != DECODER_STATE_SHUTDOWN)
{
mon.Wait();
}
if (mState == DECODER_STATE_SHUTDOWN || mStopDecodeThreads)
break;
}
PRUint32 videoQueueSize = mReader->mVideoQueue.GetSize();
// Don't decode any more frames if we've filled our buffers.
// Limits memory consumption.
if (videoQueueSize > videoWaitThreshold) {
videoWait = PR_TRUE;
}
// We don't want to consider skipping to the next keyframe if we've
// only just started up the decode loop, so wait until we've decoded
// some frames before allowing the keyframe skip.
if (videoPump && videoQueueSize >= videoPumpThreshold) {
videoPump = PR_FALSE;
}
if (!videoPump &&
videoPlaying &&
videoQueueSize < LOW_VIDEO_FRAMES)
{
skipToNextKeyframe = PR_TRUE;
}
// Determine how much audio data is decoded ahead of the current playback
// position.
int audioQueueSize = mReader->mAudioQueue.GetSize();
PRInt64 initialDownloadPosition = 0;
PRInt64 currentTime = 0;
PRInt64 audioDecoded = 0;
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
currentTime = mCurrentFrameTime + mStartTime;
audioDecoded = mReader->mAudioQueue.Duration();
if (mAudioEndTime != -1) {
audioDecoded += mAudioEndTime - currentTime;
}
initialDownloadPosition =
mDecoder->GetCurrentStream()->GetCachedDataEnd(mDecoder->mDecoderPosition);
}
// Don't decode any audio if the audio decode is way ahead.
if (audioDecoded > AMPLE_AUDIO_MS) {
audioWait = PR_TRUE;
}
if (audioPump && audioDecoded > audioPumpThresholdMs) {
audioPump = PR_FALSE;
}
if (!audioPump && audioPlaying && audioDecoded < LOW_AUDIO_MS) {
skipToNextKeyframe = PR_TRUE;
}
if (videoPlaying && !videoWait) {
videoPlaying = mReader->DecodeVideoFrame(skipToNextKeyframe, currentTime);
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (mDecoder->mDecoderPosition > initialDownloadPosition) {
mBufferExhausted = PR_TRUE;
}
}
}
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
initialDownloadPosition =
mDecoder->GetCurrentStream()->GetCachedDataEnd(mDecoder->mDecoderPosition);
mDecoder->GetMonitor().NotifyAll();
}
if (audioPlaying && !audioWait) {
audioPlaying = mReader->DecodeAudioData();
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (mDecoder->mDecoderPosition > initialDownloadPosition) {
mBufferExhausted = PR_TRUE;
}
}
}
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (!IsPlaying() &&
(!audioWait || !videoWait) &&
(videoQueueSize < 2 || audioQueueSize < 2))
{
// Transitioning from 0 to 1 frames or from 1 to 2 frames could
// affect HaveNextFrameData and hence what UpdateReadyStateForData does.
// This could change us from HAVE_CURRENT_DATA to HAVE_FUTURE_DATA
// (or even HAVE_ENOUGH_DATA), so we'd better trigger an
// update to the ready state. We only need to do this if we're
// not playing; if we're playing the playback code will post an update
// whenever it advances a frame.
UpdateReadyState();
}
if (mState == DECODER_STATE_SHUTDOWN || mStopDecodeThreads) {
break;
}
if ((!HasAudio() || (audioWait && audioPlaying)) &&
(!HasVideo() || (videoWait && videoPlaying)))
{
// All active bitstreams' decode is well ahead of the playback
// position, we may as well wait have for the playback to catch up.
mon.Wait();
}
}
}
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (!mStopDecodeThreads &&
mState != DECODER_STATE_SHUTDOWN &&
mState != DECODER_STATE_SEEKING)
{
mState = DECODER_STATE_COMPLETED;
mDecoder->GetMonitor().NotifyAll();
}
}
LOG(PR_LOG_DEBUG, ("Shutting down DecodeLoop this=%p", this));
}
PRBool nsBuiltinDecoderStateMachine::IsPlaying()
{
mDecoder->GetMonitor().AssertCurrentThreadIn();
return !mPlayStartTime.IsNull();
}
void nsBuiltinDecoderStateMachine::AudioLoop()
{
NS_ASSERTION(OnAudioThread(), "Should be on audio thread.");
LOG(PR_LOG_DEBUG, ("Begun audio thread/loop"));
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
mAudioCompleted = PR_FALSE;
}
PRInt64 audioStartTime = -1;
while (1) {
// Wait while we're not playing, and we're not shutting down, or we're
// playing and we've got no audio to play.
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
NS_ASSERTION(mState != DECODER_STATE_DECODING_METADATA,
"Should have meta data before audio started playing.");
while (mState != DECODER_STATE_SHUTDOWN &&
!mStopDecodeThreads &&
(!IsPlaying() ||
mState == DECODER_STATE_BUFFERING ||
(mReader->mAudioQueue.GetSize() == 0 &&
!mReader->mAudioQueue.AtEndOfStream())))
{
mon.Wait();
}
// If we're shutting down, break out and exit the audio thread.
if (mState == DECODER_STATE_SHUTDOWN ||
mStopDecodeThreads ||
mReader->mAudioQueue.AtEndOfStream())
{
break;
}
}
NS_ASSERTION(mReader->mAudioQueue.GetSize() > 0,
"Should have data to play");
nsAutoPtr<SoundData> sound(mReader->mAudioQueue.PopFront());
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
NS_WARN_IF_FALSE(IsPlaying(), "Should be playing");
// Awaken the decode loop if it's waiting for space to free up in the
// audio queue.
mDecoder->GetMonitor().NotifyAll();
}
if (audioStartTime == -1) {
// Remember the presentation time of the first audio sample we play.
// We add this to the position/played duration of the audio stream to
// determine the audio clock time. Used for A/V sync.
MonitorAutoEnter mon(mDecoder->GetMonitor());
mAudioStartTime = audioStartTime = sound->mTime;
LOG(PR_LOG_DEBUG, ("First audio sample has timestamp %lldms", mAudioStartTime));
}
PRInt64 audioEndTime = -1;
{
MonitorAutoEnter audioMon(mAudioMonitor);
if (mAudioStream) {
// The state machine could have paused since we've released the decoder
// monitor and acquired the audio monitor. Rather than acquire both
// monitors, the audio stream also maintains whether its paused or not.
// This prevents us from doing a blocking write while holding the audio
// monitor while paused; we would block, and the state machine won't be
// able to acquire the audio monitor in order to resume or destroy the
// audio stream.
if (!mAudioStream->IsPaused()) {
mAudioStream->Write(sound->mAudioData,
sound->AudioDataLength(),
PR_TRUE);
audioEndTime = sound->mTime + sound->mDuration;
mDecoder->UpdatePlaybackOffset(sound->mOffset);
} else {
mReader->mAudioQueue.PushFront(sound);
sound.forget();
}
}
}
sound = nsnull;
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (audioEndTime != -1) {
mAudioEndTime = audioEndTime;
}
PRInt64 audioAhead = mAudioEndTime - mCurrentFrameTime - mStartTime;
if (audioAhead > AMPLE_AUDIO_MS) {
// We've pushed enough audio onto the hardware that we've queued up a
// significant amount ahead of the playback position. The decode
// thread will be going to sleep, so we won't get any new samples
// anyway, so sleep until we need to push to the hardware again.
Wait(AMPLE_AUDIO_MS / 2);
// Kick the decode thread; since above we only do a NotifyAll when
// we pop an audio chunk of the queue, the decoder won't wake up if
// we've got no more decoded chunks to push to the hardware. We can
// hit this condition if the last sample in the stream doesn't have
// it's EOS flag set, and the decode thread sleeps just after decoding
// that packet, but before realising there's no more packets.
mon.NotifyAll();
}
}
}
if (mReader->mAudioQueue.AtEndOfStream() &&
mState != DECODER_STATE_SHUTDOWN &&
!mStopDecodeThreads)
{
// Last sample pushed to audio hardware, wait for the audio to finish,
// before the audio thread terminates.
MonitorAutoEnter audioMon(mAudioMonitor);
if (mAudioStream) {
mAudioStream->Drain();
}
LOG(PR_LOG_DEBUG, ("%p Reached audio stream end.", mDecoder));
}
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
mAudioCompleted = PR_TRUE;
UpdateReadyState();
// Kick the decode and state machine threads; they may be sleeping waiting
// for this to finish.
mDecoder->GetMonitor().NotifyAll();
}
LOG(PR_LOG_DEBUG, ("Audio stream finished playing, audio thread exit"));
}
nsresult nsBuiltinDecoderStateMachine::Init()
{
return mReader->Init();
}
void nsBuiltinDecoderStateMachine::StopPlayback(eStopMode aMode)
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
// Reset mPlayStartTime before we pause/shutdown the nsAudioStream. This is
// so that if the audio loop is about to write audio, it will have the chance
// to check to see if we're paused and not write the audio. If not, the
// audio thread can block in the write, and we deadlock trying to acquire
// the audio monitor upon resume playback.
if (IsPlaying()) {
mPlayDuration += TimeStamp::Now() - mPlayStartTime;
mPlayStartTime = TimeStamp();
}
if (HasAudio()) {
MonitorAutoExit exitMon(mDecoder->GetMonitor());
MonitorAutoEnter audioMon(mAudioMonitor);
if (mAudioStream) {
if (aMode == AUDIO_PAUSE) {
mAudioStream->Pause();
} else if (aMode == AUDIO_SHUTDOWN) {
mAudioStream->Shutdown();
mAudioStream = nsnull;
}
}
}
}
void nsBuiltinDecoderStateMachine::StartPlayback()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
NS_ASSERTION(!IsPlaying(), "Shouldn't be playing when StartPlayback() is called");
mDecoder->GetMonitor().AssertCurrentThreadIn();
LOG(PR_LOG_DEBUG, ("%p StartPlayback", mDecoder));
if (HasAudio()) {
MonitorAutoExit exitMon(mDecoder->GetMonitor());
MonitorAutoEnter audioMon(mAudioMonitor);
if (mAudioStream) {
// We have an audiostream, so it must have been paused the last time
// StopPlayback() was called.
mAudioStream->Resume();
} else {
// No audiostream, create one.
const nsVideoInfo& info = mReader->GetInfo();
mAudioStream = new nsAudioStream();
mAudioStream->Init(info.mAudioChannels,
info.mAudioRate,
nsAudioStream::FORMAT_FLOAT32);
mAudioStream->SetVolume(mVolume);
}
}
mPlayStartTime = TimeStamp::Now();
mDecoder->GetMonitor().NotifyAll();
}
void nsBuiltinDecoderStateMachine::UpdatePlaybackPosition(PRInt64 aTime)
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
NS_ASSERTION(mStartTime >= 0, "Should have positive mStartTime");
mCurrentFrameTime = aTime - mStartTime;
NS_ASSERTION(mCurrentFrameTime >= 0, "CurrentTime should be positive!");
if (aTime > mEndTime) {
NS_ASSERTION(mCurrentFrameTime > GetDuration(),
"CurrentTime must be after duration if aTime > endTime!");
mEndTime = aTime;
nsCOMPtr<nsIRunnable> event =
NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::DurationChanged);
NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
}
if (!mPositionChangeQueued) {
mPositionChangeQueued = PR_TRUE;
nsCOMPtr<nsIRunnable> event =
NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::PlaybackPositionChanged);
NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
}
}
void nsBuiltinDecoderStateMachine::ClearPositionChangeFlag()
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
mPositionChangeQueued = PR_FALSE;
}
nsHTMLMediaElement::NextFrameStatus nsBuiltinDecoderStateMachine::GetNextFrameStatus()
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (IsBuffering() || IsSeeking()) {
return nsHTMLMediaElement::NEXT_FRAME_UNAVAILABLE_BUFFERING;
} else if (HaveNextFrameData()) {
return nsHTMLMediaElement::NEXT_FRAME_AVAILABLE;
}
return nsHTMLMediaElement::NEXT_FRAME_UNAVAILABLE;
}
void nsBuiltinDecoderStateMachine::SetVolume(float volume)
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
{
MonitorAutoEnter audioMon(mAudioMonitor);
if (mAudioStream) {
mAudioStream->SetVolume(volume);
}
}
{
MonitorAutoEnter mon(mDecoder->GetMonitor());
mVolume = volume;
}
}
float nsBuiltinDecoderStateMachine::GetCurrentTime()
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
return (float)mCurrentFrameTime / 1000.0;
}
PRInt64 nsBuiltinDecoderStateMachine::GetDuration()
{
mDecoder->GetMonitor().AssertCurrentThreadIn();
if (mEndTime == -1 || mStartTime == -1)
return -1;
return mEndTime - mStartTime;
}
void nsBuiltinDecoderStateMachine::SetDuration(PRInt64 aDuration)
{
NS_ASSERTION(NS_IsMainThread() || mDecoder->OnStateMachineThread(),
"Should be on main or state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
if (mStartTime != -1) {
mEndTime = mStartTime + aDuration;
} else {
mStartTime = 0;
mEndTime = aDuration;
}
}
void nsBuiltinDecoderStateMachine::SetSeekable(PRBool aSeekable)
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
mSeekable = aSeekable;
}
void nsBuiltinDecoderStateMachine::Shutdown()
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
// Once we've entered the shutdown state here there's no going back.
MonitorAutoEnter mon(mDecoder->GetMonitor());
// Change state before issuing shutdown request to threads so those
// threads can start exiting cleanly during the Shutdown call.
LOG(PR_LOG_DEBUG, ("%p Changed state to SHUTDOWN", mDecoder));
mState = DECODER_STATE_SHUTDOWN;
mDecoder->GetMonitor().NotifyAll();
}
void nsBuiltinDecoderStateMachine::Decode()
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
// When asked to decode, switch to decoding only if
// we are currently buffering.
MonitorAutoEnter mon(mDecoder->GetMonitor());
if (mState == DECODER_STATE_BUFFERING) {
LOG(PR_LOG_DEBUG, ("%p Changed state from BUFFERING to DECODING", mDecoder));
mState = DECODER_STATE_DECODING;
mDecoder->GetMonitor().NotifyAll();
}
}
void nsBuiltinDecoderStateMachine::ResetPlayback()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
mVideoFrameEndTime = -1;
mAudioStartTime = -1;
mAudioEndTime = -1;
mAudioCompleted = PR_FALSE;
}
void nsBuiltinDecoderStateMachine::Seek(float aTime)
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
MonitorAutoEnter mon(mDecoder->GetMonitor());
// nsBuiltinDecoder::mPlayState should be SEEKING while we seek, and
// in that case nsBuiltinDecoder shouldn't be calling us.
NS_ASSERTION(mState != DECODER_STATE_SEEKING,
"We shouldn't already be seeking");
NS_ASSERTION(mState >= DECODER_STATE_DECODING,
"We should have loaded metadata");
double t = aTime * 1000.0;
if (t > PR_INT64_MAX) {
// Prevent integer overflow.
return;
}
mSeekTime = static_cast<PRInt64>(t) + mStartTime;
NS_ASSERTION(mSeekTime >= mStartTime && mSeekTime <= mEndTime,
"Can only seek in range [0,duration]");
// Bound the seek time to be inside the media range.
NS_ASSERTION(mStartTime != -1, "Should know start time by now");
NS_ASSERTION(mEndTime != -1, "Should know end time by now");
mSeekTime = NS_MIN(mSeekTime, mEndTime);
mSeekTime = NS_MAX(mStartTime, mSeekTime);
LOG(PR_LOG_DEBUG, ("%p Changed state to SEEKING (to %f)", mDecoder, aTime));
mState = DECODER_STATE_SEEKING;
}
void nsBuiltinDecoderStateMachine::StopDecodeThreads()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
mStopDecodeThreads = PR_TRUE;
mDecoder->GetMonitor().NotifyAll();
if (mDecodeThread) {
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
mDecodeThread->Shutdown();
}
mDecodeThread = nsnull;
}
if (mAudioThread) {
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
mAudioThread->Shutdown();
}
mAudioThread = nsnull;
}
}
nsresult
nsBuiltinDecoderStateMachine::StartDecodeThreads()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
mStopDecodeThreads = PR_FALSE;
if (!mDecodeThread && mState < DECODER_STATE_COMPLETED) {
nsresult rv = NS_NewThread(getter_AddRefs(mDecodeThread));
if (NS_FAILED(rv)) {
mState = DECODER_STATE_SHUTDOWN;
return rv;
}
nsCOMPtr<nsIRunnable> event =
NS_NewRunnableMethod(this, &nsBuiltinDecoderStateMachine::DecodeLoop);
mDecodeThread->Dispatch(event, NS_DISPATCH_NORMAL);
}
if (HasAudio() && !mAudioThread) {
nsresult rv = NS_NewThread(getter_AddRefs(mAudioThread));
if (NS_FAILED(rv)) {
mState = DECODER_STATE_SHUTDOWN;
return rv;
}
nsCOMPtr<nsIRunnable> event =
NS_NewRunnableMethod(this, &nsBuiltinDecoderStateMachine::AudioLoop);
mAudioThread->Dispatch(event, NS_DISPATCH_NORMAL);
}
return NS_OK;
}
nsresult nsBuiltinDecoderStateMachine::Run()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
nsMediaStream* stream = mDecoder->GetCurrentStream();
NS_ENSURE_TRUE(stream, NS_ERROR_NULL_POINTER);
while (PR_TRUE) {
MonitorAutoEnter mon(mDecoder->GetMonitor());
switch (mState) {
case DECODER_STATE_SHUTDOWN:
if (IsPlaying()) {
StopPlayback(AUDIO_SHUTDOWN);
}
StopDecodeThreads();
NS_ASSERTION(mState == DECODER_STATE_SHUTDOWN,
"How did we escape from the shutdown state???");
return NS_OK;
case DECODER_STATE_DECODING_METADATA:
{
LoadMetadata();
if (mState == DECODER_STATE_SHUTDOWN) {
continue;
}
VideoData* videoData = FindStartTime();
if (videoData) {
MonitorAutoExit exitMon(mDecoder->GetMonitor());
RenderVideoFrame(videoData);
}
// Start the decode threads, so that we can pre buffer the streams.
// and calculate the start time in order to determine the duration.
if (NS_FAILED(StartDecodeThreads())) {
continue;
}
NS_ASSERTION(mStartTime != -1, "Must have start time");
NS_ASSERTION((!HasVideo() && !HasAudio()) ||
!mSeekable || mEndTime != -1,
"Active seekable media should have end time");
NS_ASSERTION(!mSeekable || GetDuration() != -1, "Seekable media should have duration");
LOG(PR_LOG_DEBUG, ("%p Media goes from %lldms to %lldms (duration %lldms) seekable=%d",
mDecoder, mStartTime, mEndTime, GetDuration(), mSeekable));
if (mState == DECODER_STATE_SHUTDOWN)
continue;
// Inform the element that we've loaded the metadata and the
// first frame.
nsCOMPtr<nsIRunnable> metadataLoadedEvent =
NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::MetadataLoaded);
NS_DispatchToMainThread(metadataLoadedEvent, NS_DISPATCH_NORMAL);
if (mState == DECODER_STATE_DECODING_METADATA) {
LOG(PR_LOG_DEBUG, ("%p Changed state from DECODING_METADATA to DECODING", mDecoder));
mState = DECODER_STATE_DECODING;
}
// Start playback.
if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
if (!IsPlaying()) {
StartPlayback();
}
}
}
break;
case DECODER_STATE_DECODING:
{
if (NS_FAILED(StartDecodeThreads())) {
continue;
}
AdvanceFrame();
if (mState != DECODER_STATE_DECODING)
continue;
if (mBufferExhausted &&
mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING &&
!mDecoder->GetCurrentStream()->IsDataCachedToEndOfStream(mDecoder->mDecoderPosition) &&
!mDecoder->GetCurrentStream()->IsSuspendedByCache() &&
((HasAudio() && mReader->mAudioQueue.Duration() < LOW_AUDIO_MS) ||
(HasVideo() && (PRUint32)mReader->mVideoQueue.GetSize() < LOW_VIDEO_FRAMES)))
{
// There is at most one frame in the queue and there's
// more data to load. Let's buffer to make sure we can play a
// decent amount of video in the future.
if (IsPlaying()) {
StopPlayback(AUDIO_PAUSE);
mDecoder->GetMonitor().NotifyAll();
}
// We need to tell the element that buffering has started.
// We can't just directly send an asynchronous runnable that
// eventually fires the "waiting" event. The problem is that
// there might be pending main-thread events, such as "data
// received" notifications, that mean we're not actually still
// buffering by the time this runnable executes. So instead
// we just trigger UpdateReadyStateForData; when it runs, it
// will check the current state and decide whether to tell
// the element we're buffering or not.
UpdateReadyState();
mBufferingStart = TimeStamp::Now();
PRPackedBool reliable;
double playbackRate = mDecoder->ComputePlaybackRate(&reliable);
mBufferingEndOffset = mDecoder->mDecoderPosition +
BUFFERING_RATE(playbackRate) * BUFFERING_WAIT;
mState = DECODER_STATE_BUFFERING;
LOG(PR_LOG_DEBUG, ("Changed state from DECODING to BUFFERING"));
} else {
if (mBufferExhausted) {
// This will wake up the decode thread and force it to try to
// decode video and audio. This guarantees we make progress.
mBufferExhausted = PR_FALSE;
mDecoder->GetMonitor().NotifyAll();
}
}
}
break;
case DECODER_STATE_SEEKING:
{
// During the seek, don't have a lock on the decoder state,
// otherwise long seek operations can block the main thread.
// The events dispatched to the main thread are SYNC calls.
// These calls are made outside of the decode monitor lock so
// it is safe for the main thread to makes calls that acquire
// the lock since it won't deadlock. We check the state when
// acquiring the lock again in case shutdown has occurred
// during the time when we didn't have the lock.
PRInt64 seekTime = mSeekTime;
mDecoder->StopProgressUpdates();
StopPlayback(AUDIO_SHUTDOWN);
StopDecodeThreads();
ResetPlayback();
// SeekingStarted will do a UpdateReadyStateForData which will
// inform the element and its users that we have no frames
// to display
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
nsCOMPtr<nsIRunnable> startEvent =
NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::SeekingStarted);
NS_DispatchToMainThread(startEvent, NS_DISPATCH_SYNC);
}
if (mCurrentFrameTime != mSeekTime - mStartTime) {
nsresult res;
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
// Now perform the seek. We must not hold the state machine monitor
// while we seek, since the seek decodes.
res = mReader->Seek(seekTime, mStartTime, mEndTime);
}
if (NS_SUCCEEDED(res)){
SoundData* audio = HasAudio() ? mReader->mAudioQueue.PeekFront() : nsnull;
if (audio) {
mPlayDuration = TimeDuration::FromMilliseconds(audio->mTime);
}
if (HasVideo()) {
nsAutoPtr<VideoData> video(mReader->mVideoQueue.PeekFront());
if (video) {
RenderVideoFrame(video);
if (!audio) {
NS_ASSERTION(video->mTime <= seekTime &&
seekTime <= video->mEndTime,
"Seek target should lie inside the first frame after seek");
mPlayDuration = TimeDuration::FromMilliseconds(seekTime);
}
}
mReader->mVideoQueue.PopFront();
}
UpdatePlaybackPosition(seekTime);
}
}
mDecoder->StartProgressUpdates();
if (mState == DECODER_STATE_SHUTDOWN)
continue;
// Try to decode another frame to detect if we're at the end...
LOG(PR_LOG_DEBUG, ("Seek completed, mCurrentFrameTime=%lld\n", mCurrentFrameTime));
// Change state to DECODING or COMPLETED now. SeekingStopped will
// call nsBuiltinDecoderStateMachine::Seek to reset our state to SEEKING
// if we need to seek again.
nsCOMPtr<nsIRunnable> stopEvent;
if (mCurrentFrameTime == mEndTime) {
LOG(PR_LOG_DEBUG, ("%p Changed state from SEEKING (to %lldms) to COMPLETED",
mDecoder, seekTime));
stopEvent = NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::SeekingStoppedAtEnd);
mState = DECODER_STATE_COMPLETED;
} else {
LOG(PR_LOG_DEBUG, ("%p Changed state from SEEKING (to %lldms) to DECODING",
mDecoder, seekTime));
stopEvent = NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::SeekingStopped);
mState = DECODER_STATE_DECODING;
}
mBufferExhausted = PR_FALSE;
mDecoder->GetMonitor().NotifyAll();
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
NS_DispatchToMainThread(stopEvent, NS_DISPATCH_SYNC);
}
}
break;
case DECODER_STATE_BUFFERING:
{
TimeStamp now = TimeStamp::Now();
if (now - mBufferingStart < TimeDuration::FromSeconds(BUFFERING_WAIT) &&
mDecoder->GetCurrentStream()->GetCachedDataEnd(mDecoder->mDecoderPosition) < mBufferingEndOffset &&
!mDecoder->GetCurrentStream()->IsDataCachedToEndOfStream(mDecoder->mDecoderPosition) &&
!mDecoder->GetCurrentStream()->IsSuspendedByCache()) {
LOG(PR_LOG_DEBUG,
("In buffering: buffering data until %d bytes available or %f seconds",
PRUint32(mBufferingEndOffset - mDecoder->GetCurrentStream()->GetCachedDataEnd(mDecoder->mDecoderPosition)),
BUFFERING_WAIT - (now - mBufferingStart).ToSeconds()));
Wait(1000);
if (mState == DECODER_STATE_SHUTDOWN)
continue;
} else {
LOG(PR_LOG_DEBUG, ("%p Changed state from BUFFERING to DECODING", mDecoder));
LOG(PR_LOG_DEBUG, ("%p Buffered for %lf seconds",
mDecoder,
(TimeStamp::Now() - mBufferingStart).ToSeconds()));
mState = DECODER_STATE_DECODING;
}
if (mState != DECODER_STATE_BUFFERING) {
mBufferExhausted = PR_FALSE;
// Notify to allow blocked decoder thread to continue
mDecoder->GetMonitor().NotifyAll();
UpdateReadyState();
if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
if (!IsPlaying()) {
StartPlayback();
}
}
}
break;
}
case DECODER_STATE_COMPLETED:
{
if (NS_FAILED(StartDecodeThreads())) {
continue;
}
// Play the remaining media. We want to run AdvanceFrame() at least
// once to ensure the current playback position is advanced to the
// end of the media, and so that we update the readyState.
do {
AdvanceFrame();
} while (mState == DECODER_STATE_COMPLETED &&
(mReader->mVideoQueue.GetSize() > 0 ||
(HasAudio() && !mAudioCompleted)));
if (mAudioStream) {
// Close the audio stream so that next time audio is used a new stream
// is created. The StopPlayback call also resets the IsPlaying() state
// so audio is restarted correctly.
StopPlayback(AUDIO_SHUTDOWN);
}
if (mState != DECODER_STATE_COMPLETED)
continue;
LOG(PR_LOG_DEBUG, ("Shutting down the state machine thread"));
StopDecodeThreads();
if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
PRInt64 videoTime = HasVideo() ? mVideoFrameEndTime : 0;
PRInt64 clockTime = NS_MAX(mEndTime, NS_MAX(videoTime, GetAudioClock()));
UpdatePlaybackPosition(clockTime);
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
nsCOMPtr<nsIRunnable> event =
NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::PlaybackEnded);
NS_DispatchToMainThread(event, NS_DISPATCH_SYNC);
}
}
while (mState == DECODER_STATE_COMPLETED) {
mDecoder->GetMonitor().Wait();
}
}
break;
}
}
return NS_OK;
}
void nsBuiltinDecoderStateMachine::RenderVideoFrame(VideoData* aData)
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread), "Should be on state machine thread.");
if (aData->mDuplicate) {
return;
}
nsRefPtr<Image> image = aData->mImage;
if (image) {
const nsVideoInfo& info = mReader->GetInfo();
mDecoder->SetVideoData(gfxIntSize(info.mPicture.width, info.mPicture.height), info.mPixelAspectRatio, image);
}
}
PRInt64
nsBuiltinDecoderStateMachine::GetAudioClock()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread), "Should be on state machine thread.");
if (!mAudioStream || !HasAudio())
return -1;
PRInt64 t = mAudioStream->GetPosition();
return (t == -1) ? -1 : t + mAudioStartTime;
}
void nsBuiltinDecoderStateMachine::AdvanceFrame()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread), "Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
// When it's time to display a frame, decode the frame and display it.
if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING) {
if (!IsPlaying()) {
StartPlayback();
mDecoder->GetMonitor().NotifyAll();
}
if (HasAudio() && mAudioStartTime == -1 && !mAudioCompleted) {
// We've got audio (so we should sync off the audio clock), but we've not
// played a sample on the audio thread, so we can't get a time from the
// audio clock. Just wait and then return, to give the audio clock time
// to tick. This should really wait for a specific signal from the audio
// thread rather than polling after a sleep. See bug 568431 comment 4.
Wait(AUDIO_DURATION_MS);
return;
}
// Determine the clock time. If we've got audio, and we've not reached
// the end of the audio, use the audio clock. However if we've finished
// audio, or don't have audio, use the system clock.
PRInt64 clock_time = -1;
PRInt64 audio_time = GetAudioClock();
if (HasAudio() && !mAudioCompleted && audio_time != -1) {
clock_time = audio_time;
// Resync against the audio clock, while we're trusting the
// audio clock. This ensures no "drift", particularly on Linux.
mPlayStartTime = TimeStamp::Now() - TimeDuration::FromMilliseconds(clock_time);
} else {
// Sound is disabled on this system. Sync to the system clock.
TimeDuration t = TimeStamp::Now() - mPlayStartTime + mPlayDuration;
clock_time = (PRInt64)(1000 * t.ToSeconds());
// Ensure the clock can never go backwards.
NS_ASSERTION(mCurrentFrameTime <= clock_time, "Clock should go forwards");
clock_time = NS_MAX(mCurrentFrameTime, clock_time) + mStartTime;
}
NS_ASSERTION(clock_time >= mStartTime, "Should have positive clock time.");
nsAutoPtr<VideoData> videoData;
if (mReader->mVideoQueue.GetSize() > 0) {
VideoData* data = mReader->mVideoQueue.PeekFront();
while (clock_time >= data->mTime) {
mVideoFrameEndTime = data->mEndTime;
videoData = data;
mReader->mVideoQueue.PopFront();
mDecoder->UpdatePlaybackOffset(data->mOffset);
if (mReader->mVideoQueue.GetSize() == 0)
break;
data = mReader->mVideoQueue.PeekFront();
}
}
PRInt64 frameDuration = AUDIO_DURATION_MS;
if (videoData) {
// Decode one frame and display it
NS_ASSERTION(videoData->mTime >= mStartTime, "Should have positive frame time");
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
// If we have video, we want to increment the clock in steps of the frame
// duration.
RenderVideoFrame(videoData);
}
mDecoder->GetMonitor().NotifyAll();
frameDuration = videoData->mEndTime - videoData->mTime;
videoData = nsnull;
}
// Cap the current time to the larger of the audio and video end time.
// This ensures that if we're running off the system clock, we don't
// advance the clock to after the media end time.
if (mVideoFrameEndTime != -1 || mAudioEndTime != -1) {
// These will be non -1 if we've displayed a video frame, or played an audio sample.
clock_time = NS_MIN(clock_time, NS_MAX(mVideoFrameEndTime, mAudioEndTime));
if (clock_time - mStartTime > mCurrentFrameTime) {
// Only update the playback position if the clock time is greater
// than the previous playback position. The audio clock can
// sometimes report a time less than its previously reported in
// some situations, and we need to gracefully handle that.
UpdatePlaybackPosition(clock_time);
}
}
// If the number of audio/video samples queued has changed, either by
// this function popping and playing a video sample, or by the audio
// thread popping and playing an audio sample, we may need to update our
// ready state. Post an update to do so.
UpdateReadyState();
Wait(frameDuration);
} else {
if (IsPlaying()) {
StopPlayback(AUDIO_PAUSE);
mDecoder->GetMonitor().NotifyAll();
}
if (mState == DECODER_STATE_DECODING ||
mState == DECODER_STATE_COMPLETED) {
mDecoder->GetMonitor().Wait();
}
}
}
void nsBuiltinDecoderStateMachine::Wait(PRUint32 aMs) {
mDecoder->GetMonitor().AssertCurrentThreadIn();
TimeStamp end = TimeStamp::Now() + TimeDuration::FromMilliseconds(aMs);
TimeStamp now;
while ((now = TimeStamp::Now()) < end &&
mState != DECODER_STATE_SHUTDOWN &&
mState != DECODER_STATE_SEEKING)
{
TimeDuration d = end - now;
PRInt64 ms = d.ToSeconds() * 1000;
if (ms == 0) {
break;
}
NS_ASSERTION(ms <= aMs && ms > 0,
"nsBuiltinDecoderStateMachine::Wait interval very wrong!");
mDecoder->GetMonitor().Wait(PR_MillisecondsToInterval(ms));
}
}
VideoData* nsBuiltinDecoderStateMachine::FindStartTime()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread), "Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
PRInt64 startTime = 0;
mStartTime = 0;
VideoData* v = nsnull;
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
v = mReader->FindStartTime(mReader->GetInfo().mDataOffset, startTime);
}
if (startTime != 0) {
mStartTime = startTime;
if (mGotDurationFromHeader) {
NS_ASSERTION(mEndTime != -1,
"We should have mEndTime as supplied duration here");
// We were specified a duration from a Content-Duration HTTP header.
// Adjust mEndTime so that mEndTime-mStartTime matches the specified
// duration.
mEndTime = mStartTime + mEndTime;
}
}
LOG(PR_LOG_DEBUG, ("%p Media start time is %lldms", mDecoder, mStartTime));
return v;
}
void nsBuiltinDecoderStateMachine::FindEndTime()
{
NS_ASSERTION(OnStateMachineThread(), "Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
nsMediaStream* stream = mDecoder->GetCurrentStream();
// Seek to the end of file to find the length and duration.
PRInt64 length = stream->GetLength();
NS_ASSERTION(length > 0, "Must have a content length to get end time");
mEndTime = 0;
PRInt64 endTime = 0;
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
endTime = mReader->FindEndTime(length);
}
if (endTime != -1) {
mEndTime = endTime;
}
LOG(PR_LOG_DEBUG, ("%p Media end time is %lldms", mDecoder, mEndTime));
}
void nsBuiltinDecoderStateMachine::UpdateReadyState() {
mDecoder->GetMonitor().AssertCurrentThreadIn();
nsCOMPtr<nsIRunnable> event;
switch (GetNextFrameStatus()) {
case nsHTMLMediaElement::NEXT_FRAME_UNAVAILABLE_BUFFERING:
event = NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::NextFrameUnavailableBuffering);
break;
case nsHTMLMediaElement::NEXT_FRAME_AVAILABLE:
event = NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::NextFrameAvailable);
break;
case nsHTMLMediaElement::NEXT_FRAME_UNAVAILABLE:
event = NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::NextFrameUnavailable);
break;
default:
PR_NOT_REACHED("unhandled frame state");
}
NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
}
void nsBuiltinDecoderStateMachine::LoadMetadata()
{
NS_ASSERTION(IsCurrentThread(mDecoder->mStateMachineThread),
"Should be on state machine thread.");
mDecoder->GetMonitor().AssertCurrentThreadIn();
LOG(PR_LOG_DEBUG, ("Loading Media Headers"));
{
MonitorAutoExit exitMon(mDecoder->GetMonitor());
mReader->ReadMetadata();
}
mDecoder->StartProgressUpdates();
const nsVideoInfo& info = mReader->GetInfo();
if (!info.mHasVideo && !info.mHasAudio) {
mState = DECODER_STATE_SHUTDOWN;
nsCOMPtr<nsIRunnable> event =
NS_NewRunnableMethod(mDecoder, &nsBuiltinDecoder::DecodeError);
NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
return;
}
}
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