Deliver video frames on Android, on the decode thread.

webrtc/modules/video_coding/generic_decoder.cc

Index: webrtc/modules/video_coding/generic_decoder.cc
diff --git a/webrtc/modules/video_coding/generic_decoder.cc b/webrtc/modules/video_coding/generic_decoder.cc
index cc14794e090ce94121bbec4af8ef7458ae61f03a..5c79c4c8dc79f4473c5fe097791037e9b8e464e0 100644
--- a/webrtc/modules/video_coding/generic_decoder.cc
+++ b/webrtc/modules/video_coding/generic_decoder.cc
@@ -28,11 +28,13 @@ VCMDecodedFrameCallback::VCMDecodedFrameCallback(VCMTiming* timing,
       _timing(timing),
       _timestampMap(kDecoderFrameMemoryLength),
       _lastReceivedPictureID(0) {
+  decoder_thread_.DetachFromThread();
   ntp_offset_ =
       _clock->CurrentNtpInMilliseconds() - _clock->TimeInMilliseconds();
 }
 
 VCMDecodedFrameCallback::~VCMDecodedFrameCallback() {
+  RTC_DCHECK(construction_thread_.CalledOnValidThread());
 }
 
 void VCMDecodedFrameCallback::SetUserReceiveCallback(
@@ -41,9 +43,15 @@ void VCMDecodedFrameCallback::SetUserReceiveCallback(
   RTC_DCHECK((!_receiveCallback && receiveCallback) ||
              (_receiveCallback && !receiveCallback));
   _receiveCallback = receiveCallback;
+  // When the callback is cleared, it signals to us that the decoder thread
+  // is no longer running. Another decoder thread might be started, so it's
+  // important to reset the thread checker first.
+  if (!receiveCallback)
+    decoder_thread_.DetachFromThread();
 }
 
 VCMReceiveCallback* VCMDecodedFrameCallback::UserReceiveCallback() {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   // Called on the decode thread via VCMCodecDataBase::GetDecoder.
   // The callback must always have been set before this happens.
   RTC_DCHECK(_receiveCallback);
@@ -66,16 +74,14 @@ int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
 void VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
                                       rtc::Optional<int32_t> decode_time_ms,
                                       rtc::Optional<uint8_t> qp) {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   RTC_DCHECK(_receiveCallback) << "Callback must not be null at this point";
+
   TRACE_EVENT_INSTANT1("webrtc", "VCMDecodedFrameCallback::Decoded",
                        "timestamp", decodedImage.timestamp());
   // TODO(holmer): We should improve this so that we can handle multiple
   // callbacks from one call to Decode().
-  VCMFrameInformation* frameInfo;
-  {
-    rtc::CritScope cs(&lock_);
-    frameInfo = _timestampMap.Pop(decodedImage.timestamp());
-  }
+  VCMFrameInformation* frameInfo = _timestampMap.Pop(decodedImage.timestamp());
 
   if (frameInfo == NULL) {
     LOG(LS_WARNING) << "Too many frames backed up in the decoder, dropping "
@@ -149,36 +155,37 @@ void VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
 
 int32_t VCMDecodedFrameCallback::ReceivedDecodedReferenceFrame(
     const uint64_t pictureId) {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   return _receiveCallback->ReceivedDecodedReferenceFrame(pictureId);
 }
 
 int32_t VCMDecodedFrameCallback::ReceivedDecodedFrame(
     const uint64_t pictureId) {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   _lastReceivedPictureID = pictureId;
   return 0;
 }
 
 uint64_t VCMDecodedFrameCallback::LastReceivedPictureID() const {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   return _lastReceivedPictureID;
 }
 
 void VCMDecodedFrameCallback::OnDecoderImplementationName(
     const char* implementation_name) {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   _receiveCallback->OnDecoderImplementationName(implementation_name);
 }
 
 void VCMDecodedFrameCallback::Map(uint32_t timestamp,
                                   VCMFrameInformation* frameInfo) {
-  rtc::CritScope cs(&lock_);
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   _timestampMap.Add(timestamp, frameInfo);
 }
 
 int32_t VCMDecodedFrameCallback::Pop(uint32_t timestamp) {
-  rtc::CritScope cs(&lock_);
-  if (_timestampMap.Pop(timestamp) == NULL) {
-    return VCM_GENERAL_ERROR;
-  }
-  return VCM_OK;
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
+  return _timestampMap.Pop(timestamp) == nullptr ? VCM_GENERAL_ERROR : VCM_OK;
 }
 
 VCMGenericDecoder::VCMGenericDecoder(VideoDecoder* decoder, bool isExternal)
@@ -201,6 +208,7 @@ VCMGenericDecoder::~VCMGenericDecoder() {
 
 int32_t VCMGenericDecoder::InitDecode(const VideoCodec* settings,
                                       int32_t numberOfCores) {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   TRACE_EVENT0("webrtc", "VCMGenericDecoder::InitDecode");
   _codecType = settings->codecType;
 
@@ -208,51 +216,66 @@ int32_t VCMGenericDecoder::InitDecode(const VideoCodec* settings,
 }
 
 int32_t VCMGenericDecoder::Decode(const VCMEncodedFrame& frame, int64_t nowMs) {
-    TRACE_EVENT1("webrtc", "VCMGenericDecoder::Decode", "timestamp",
-                 frame.EncodedImage()._timeStamp);
-    _frameInfos[_nextFrameInfoIdx].decodeStartTimeMs = nowMs;
-    _frameInfos[_nextFrameInfoIdx].renderTimeMs = frame.RenderTimeMs();
-    _frameInfos[_nextFrameInfoIdx].rotation = frame.rotation();
-    _frameInfos[_nextFrameInfoIdx].timing = frame.video_timing();
-    // Set correctly only for key frames. Thus, use latest key frame
-    // content type. If the corresponding key frame was lost, decode will fail
-    // and content type will be ignored.
-    if (frame.FrameType() == kVideoFrameKey) {
-      _frameInfos[_nextFrameInfoIdx].content_type = frame.contentType();
-      _last_keyframe_content_type = frame.contentType();
-    } else {
-      _frameInfos[_nextFrameInfoIdx].content_type = _last_keyframe_content_type;
-    }
-    _callback->Map(frame.TimeStamp(), &_frameInfos[_nextFrameInfoIdx]);
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
+  TRACE_EVENT2("webrtc", "VCMGenericDecoder::Decode", "timestamp",
+               frame.EncodedImage()._timeStamp, "decoder",
+               decoder_->ImplementationName());
+  _frameInfos[_nextFrameInfoIdx].decodeStartTimeMs = nowMs;
+  _frameInfos[_nextFrameInfoIdx].renderTimeMs = frame.RenderTimeMs();
+  _frameInfos[_nextFrameInfoIdx].rotation = frame.rotation();
+  _frameInfos[_nextFrameInfoIdx].timing = frame.video_timing();
+  // Set correctly only for key frames. Thus, use latest key frame
+  // content type. If the corresponding key frame was lost, decode will fail
+  // and content type will be ignored.
+  if (frame.FrameType() == kVideoFrameKey) {
+    _frameInfos[_nextFrameInfoIdx].content_type = frame.contentType();
+    _last_keyframe_content_type = frame.contentType();
+  } else {
+    _frameInfos[_nextFrameInfoIdx].content_type = _last_keyframe_content_type;
+  }
+  _callback->Map(frame.TimeStamp(), &_frameInfos[_nextFrameInfoIdx]);
 
-    _nextFrameInfoIdx = (_nextFrameInfoIdx + 1) % kDecoderFrameMemoryLength;
-    const RTPFragmentationHeader dummy_header;
-    int32_t ret = decoder_->Decode(frame.EncodedImage(), frame.MissingFrame(),
-                                   &dummy_header,
-                                   frame.CodecSpecific(), frame.RenderTimeMs());
+  _nextFrameInfoIdx = (_nextFrameInfoIdx + 1) % kDecoderFrameMemoryLength;
+  const RTPFragmentationHeader dummy_header;
+  int32_t ret = decoder_->Decode(frame.EncodedImage(), frame.MissingFrame(),
+                                 &dummy_header, frame.CodecSpecific(),
+                                 frame.RenderTimeMs());
 
-    _callback->OnDecoderImplementationName(decoder_->ImplementationName());
+  // TODO(tommi): Necessary every time?
+  // Maybe this should be the first thing the function does, and only the first
+  // time around?
+  _callback->OnDecoderImplementationName(decoder_->ImplementationName());
+
+  if (ret != WEBRTC_VIDEO_CODEC_OK) {
     if (ret < WEBRTC_VIDEO_CODEC_OK) {
-        LOG(LS_WARNING) << "Failed to decode frame with timestamp "
-                        << frame.TimeStamp() << ", error code: " << ret;
-        _callback->Pop(frame.TimeStamp());
-        return ret;
-    } else if (ret == WEBRTC_VIDEO_CODEC_NO_OUTPUT ||
-               ret == WEBRTC_VIDEO_CODEC_REQUEST_SLI) {
-        // No output
-        _callback->Pop(frame.TimeStamp());
+      LOG(LS_WARNING) << "Failed to decode frame with timestamp "
+                      << frame.TimeStamp() << ", error code: " << ret;
     }
-    return ret;
+    // We pop the frame for all non-'OK', failure or success codes such as
+    // WEBRTC_VIDEO_CODEC_NO_OUTPUT and WEBRTC_VIDEO_CODEC_REQUEST_SLI.
+    _callback->Pop(frame.TimeStamp());
+  }
+
+  return ret;
 }
 
 int32_t VCMGenericDecoder::RegisterDecodeCompleteCallback(
     VCMDecodedFrameCallback* callback) {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   _callback = callback;
   return decoder_->RegisterDecodeCompleteCallback(callback);
 }
 
 bool VCMGenericDecoder::PrefersLateDecoding() const {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
   return decoder_->PrefersLateDecoding();
 }
 
+#if defined(WEBRTC_ANDROID)
+void VCMGenericDecoder::PollDecodedFrames() {
+  RTC_DCHECK_RUN_ON(&decoder_thread_);
+  decoder_->PollDecodedFrames();
+}
+#endif
+
 }  // namespace webrtc