The Tor Browser: content/media/MediaDecoderReader.cpp@97036ab72558 (annotated)

content/media/MediaDecoderReader.cpp@97036ab72558 (annotated)

content/media/MediaDecoderReader.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "MediaDecoderReader.h"
 #include "AbstractMediaDecoder.h"
 #include "VideoUtils.h"
 #include "ImageContainer.h"
 #include "mozilla/mozalloc.h"
 #include <stdint.h>
 #include <algorithm>
 namespace mozilla {
 // Un-comment to enable logging of seek bisections.
 //#define SEEK_LOGGING
 #ifdef PR_LOGGING
 extern PRLogModuleInfo* gMediaDecoderLog;
 #define DECODER_LOG(type, msg) PR_LOG(gMediaDecoderLog, type, msg)
 #ifdef SEEK_LOGGING
 #define SEEK_LOG(type, msg) PR_LOG(gMediaDecoderLog, type, msg)
 #else
 #define SEEK_LOG(type, msg)
 #endif
 #else
 #define DECODER_LOG(type, msg)
 #define SEEK_LOG(type, msg)
 #endif
 class VideoQueueMemoryFunctor : public nsDequeFunctor {
 public:
   VideoQueueMemoryFunctor() : mSize(0) {}
   MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf);
   virtual void* operator()(void* aObject) {
     const VideoData* v = static_cast<const VideoData*>(aObject);
     mSize += v->SizeOfIncludingThis(MallocSizeOf);
     return nullptr;
   }
   size_t mSize;
 };
 class AudioQueueMemoryFunctor : public nsDequeFunctor {
 public:
   AudioQueueMemoryFunctor() : mSize(0) {}
   MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf);
   virtual void* operator()(void* aObject) {
     const AudioData* audioData = static_cast<const AudioData*>(aObject);
     mSize += audioData->SizeOfIncludingThis(MallocSizeOf);
     return nullptr;
   }
   size_t mSize;
 };
 MediaDecoderReader::MediaDecoderReader(AbstractMediaDecoder* aDecoder)
   : mAudioCompactor(mAudioQueue),
     mDecoder(aDecoder),
     mIgnoreAudioOutputFormat(false)
 {
   MOZ_COUNT_CTOR(MediaDecoderReader);
 }
 MediaDecoderReader::~MediaDecoderReader()
 {
   ResetDecode();
   MOZ_COUNT_DTOR(MediaDecoderReader);
 }
 size_t MediaDecoderReader::SizeOfVideoQueueInBytes() const
 {
   VideoQueueMemoryFunctor functor;
   mVideoQueue.LockedForEach(functor);
   return functor.mSize;
 }
 size_t MediaDecoderReader::SizeOfAudioQueueInBytes() const
 {
   AudioQueueMemoryFunctor functor;
   mAudioQueue.LockedForEach(functor);
   return functor.mSize;
 }
 nsresult MediaDecoderReader::ResetDecode()
 {
   nsresult res = NS_OK;
   VideoQueue().Reset();
   AudioQueue().Reset();
   return res;
 }
 VideoData* MediaDecoderReader::DecodeToFirstVideoData()
 {
   bool eof = false;
   while (!eof && VideoQueue().GetSize() == 0) {
     {
       ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
       if (mDecoder->IsShutdown()) {
         return nullptr;
       }
     }
     bool keyframeSkip = false;
     eof = !DecodeVideoFrame(keyframeSkip, 0);
   }
   if (eof) {
     VideoQueue().Finish();
   }
   VideoData* d = nullptr;
   return (d = VideoQueue().PeekFront()) ? d : nullptr;
 }
 AudioData* MediaDecoderReader::DecodeToFirstAudioData()
 {
   bool eof = false;
   while (!eof && AudioQueue().GetSize() == 0) {
     {
       ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
       if (mDecoder->IsShutdown()) {
         return nullptr;
       }
     }
     eof = !DecodeAudioData();
   }
   if (eof) {
     AudioQueue().Finish();
   }
   AudioData* d = nullptr;
   return (d = AudioQueue().PeekFront()) ? d : nullptr;
 }
 VideoData* MediaDecoderReader::FindStartTime(int64_t& aOutStartTime)
 {
   NS_ASSERTION(mDecoder->OnStateMachineThread() || mDecoder->OnDecodeThread(),
                "Should be on state machine or decode thread.");
   // Extract the start times of the bitstreams in order to calculate
   // the duration.
   int64_t videoStartTime = INT64_MAX;
   int64_t audioStartTime = INT64_MAX;
   VideoData* videoData = nullptr;
   if (HasVideo()) {
     videoData = DecodeToFirstVideoData();
     if (videoData) {
       videoStartTime = videoData->mTime;
       DECODER_LOG(PR_LOG_DEBUG, ("MediaDecoderReader::FindStartTime() video=%lld", videoStartTime));
     }
   }
   if (HasAudio()) {
     AudioData* audioData = DecodeToFirstAudioData();
     if (audioData) {
       audioStartTime = audioData->mTime;
       DECODER_LOG(PR_LOG_DEBUG, ("MediaDecoderReader::FindStartTime() audio=%lld", audioStartTime));
     }
   }
   int64_t startTime = std::min(videoStartTime, audioStartTime);
   if (startTime != INT64_MAX) {
     aOutStartTime = startTime;
   }
   return videoData;
 }
 nsresult MediaDecoderReader::DecodeToTarget(int64_t aTarget)
 {
   DECODER_LOG(PR_LOG_DEBUG, ("MediaDecoderReader::DecodeToTarget(%lld) Begin", aTarget));
   // Decode forward to the target frame. Start with video, if we have it.
   if (HasVideo()) {
     // Note: when decoding hits the end of stream we must keep the last frame
     // in the video queue so that we'll have something to display after the
     // seek completes. This makes our logic a bit messy.
     bool eof = false;
     nsAutoPtr<VideoData> video;
     while (HasVideo() && !eof) {
       while (VideoQueue().GetSize() == 0 && !eof) {
         bool skip = false;
         eof = !DecodeVideoFrame(skip, 0);
         {
           ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
           if (mDecoder->IsShutdown()) {
             return NS_ERROR_FAILURE;
           }
         }
       }
       if (eof) {
         // Hit end of file, we want to display the last frame of the video.
         if (video) {
           DECODER_LOG(PR_LOG_DEBUG,
             ("MediaDecoderReader::DecodeToTarget(%lld) repushing video frame [%lld, %lld] at EOF",
             aTarget, video->mTime, video->GetEndTime()));
           VideoQueue().PushFront(video.forget());
         }
         VideoQueue().Finish();
         break;
       }
       video = VideoQueue().PeekFront();
       // If the frame end time is less than the seek target, we won't want
       // to display this frame after the seek, so discard it.
       if (video && video->GetEndTime() <= aTarget) {
         DECODER_LOG(PR_LOG_DEBUG,
                     ("MediaDecoderReader::DecodeToTarget(%lld) pop video frame [%lld, %lld]",
                      aTarget, video->mTime, video->GetEndTime()));
         VideoQueue().PopFront();
       } else {
         // Found a frame after or encompasing the seek target.
         if (aTarget >= video->mTime && video->GetEndTime() >= aTarget) {
           // The seek target lies inside this frame's time slice. Adjust the frame's
           // start time to match the seek target. We do this by replacing the
           // first frame with a shallow copy which has the new timestamp.
           VideoQueue().PopFront();
           VideoData* temp = VideoData::ShallowCopyUpdateTimestamp(video, aTarget);
           video = temp;
           VideoQueue().PushFront(video);
         }
         DECODER_LOG(PR_LOG_DEBUG,
                     ("MediaDecoderReader::DecodeToTarget(%lld) found target video frame [%lld,%lld]",
                      aTarget, video->mTime, video->GetEndTime()));
         video.forget();
         break;
       }
     }
     {
       ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
       if (mDecoder->IsShutdown()) {
         return NS_ERROR_FAILURE;
       }
     }
 #ifdef PR_LOGGING
     const VideoData* front =  VideoQueue().PeekFront();
     DECODER_LOG(PR_LOG_DEBUG, ("First video frame after decode is %lld",
                 front ? front->mTime : -1));
 #endif
   }
   if (HasAudio()) {
     // Decode audio forward to the seek target.
     bool eof = false;
     while (HasAudio() && !eof) {
       while (!eof && AudioQueue().GetSize() == 0) {
         eof = !DecodeAudioData();
         {
           ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
           if (mDecoder->IsShutdown()) {
             return NS_ERROR_FAILURE;
           }
         }
       }
       const AudioData* audio = AudioQueue().PeekFront();
       if (!audio || eof) {
         AudioQueue().Finish();
         break;
       }
       CheckedInt64 startFrame = UsecsToFrames(audio->mTime, mInfo.mAudio.mRate);
       CheckedInt64 targetFrame = UsecsToFrames(aTarget, mInfo.mAudio.mRate);
       if (!startFrame.isValid() || !targetFrame.isValid()) {
         return NS_ERROR_FAILURE;
       }
       if (startFrame.value() + audio->mFrames <= targetFrame.value()) {
         // Our seek target lies after the frames in this AudioData. Pop it
         // off the queue, and keep decoding forwards.
         delete AudioQueue().PopFront();
         audio = nullptr;
         continue;
       }
       if (startFrame.value() > targetFrame.value()) {
         // The seek target doesn't lie in the audio block just after the last
         // audio frames we've seen which were before the seek target. This
         // could have been the first audio data we've seen after seek, i.e. the
         // seek terminated after the seek target in the audio stream. Just
         // abort the audio decode-to-target, the state machine will play
         // silence to cover the gap. Typically this happens in poorly muxed
         // files.
         NS_WARNING("Audio not synced after seek, maybe a poorly muxed file?");
         break;
       }
       // The seek target lies somewhere in this AudioData's frames, strip off
       // any frames which lie before the seek target, so we'll begin playback
       // exactly at the seek target.
       NS_ASSERTION(targetFrame.value() >= startFrame.value(),
                    "Target must at or be after data start.");
       NS_ASSERTION(targetFrame.value() < startFrame.value() + audio->mFrames,
                    "Data must end after target.");
       int64_t framesToPrune = targetFrame.value() - startFrame.value();
       if (framesToPrune > audio->mFrames) {
         // We've messed up somehow. Don't try to trim frames, the |frames|
         // variable below will overflow.
         NS_WARNING("Can't prune more frames that we have!");
         break;
       }
       uint32_t frames = audio->mFrames - static_cast<uint32_t>(framesToPrune);
       uint32_t channels = audio->mChannels;
       nsAutoArrayPtr<AudioDataValue> audioData(new AudioDataValue[frames * channels]);
       memcpy(audioData.get(),
              audio->mAudioData.get() + (framesToPrune * channels),
              frames * channels * sizeof(AudioDataValue));
       CheckedInt64 duration = FramesToUsecs(frames, mInfo.mAudio.mRate);
       if (!duration.isValid()) {
         return NS_ERROR_FAILURE;
       }
       nsAutoPtr<AudioData> data(new AudioData(audio->mOffset,
                                               aTarget,
                                               duration.value(),
                                               frames,
                                               audioData.forget(),
                                               channels));
       delete AudioQueue().PopFront();
       AudioQueue().PushFront(data.forget());
       break;
     }
   }
 #ifdef PR_LOGGING
   const VideoData* v = VideoQueue().PeekFront();
   const AudioData* a = AudioQueue().PeekFront();
   DECODER_LOG(PR_LOG_DEBUG,
               ("MediaDecoderReader::DecodeToTarget(%lld) finished v=%lld a=%lld",
               aTarget, v ? v->mTime : -1, a ? a->mTime : -1));
 #endif
   return NS_OK;
 }
 nsresult
 MediaDecoderReader::GetBuffered(mozilla::dom::TimeRanges* aBuffered,
                                 int64_t aStartTime)
 {
   MediaResource* stream = mDecoder->GetResource();
   int64_t durationUs = 0;
   {
     ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
     durationUs = mDecoder->GetMediaDuration();
   }
   GetEstimatedBufferedTimeRanges(stream, durationUs, aBuffered);
   return NS_OK;
 }
 } // namespace mozilla

The Tor Browser / annotate

content/media/MediaDecoderReader.cpp@97036ab72558 (annotated)

content/media/MediaDecoderReader.cpp