Fix processing of multiple stream status changes by renderer

media/renderers/renderer_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/renderers/renderer_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 14 matching lines @@
 #include "media/base/video_renderer.h"
 #include "media/base/wall_clock_time_source.h"
 
 namespace media {
 
 // See |video_underflow_threshold_|.
 static const int kDefaultVideoUnderflowThresholdMs = 3000;
 
 static const int kAudioRestartUnderflowThresholdMs = 2000;
 
+// Specifies the delay for postponed stream status changes while another status
+// change of the same stream type is being handled.
+static const int kStreamStatusHandlingDelayMs = 10;

[xhwang, 2017/01/04 19:34:02]

nit: no need to use "static" here. Namespace scope constant is already static.

[servolk, 2017/01/04 21:29:30]

Done.

+
 class RendererImpl::RendererClientInternal : public RendererClient {
  public:
   RendererClientInternal(DemuxerStream::Type type, RendererImpl* renderer)
       : type_(type), renderer_(renderer) {
     DCHECK((type_ == DemuxerStream::AUDIO) || (type_ == DemuxerStream::VIDEO));
   }
 
   void OnError(PipelineStatus error) override { renderer_->OnError(error); }
   void OnEnded() override { renderer_->OnRendererEnded(type_); }
   void OnStatisticsUpdate(const PipelineStatistics& stats) override {
@@ skipping 156 matching lines @@
   }
 
   time_source_->SetMediaTime(time);
 
   if (audio_renderer_)
     audio_renderer_->StartPlaying();
   if (video_renderer_)
     video_renderer_->StartPlayingFrom(time);
 }
 
-void RendererImpl::RestartStreamPlayback(DemuxerStream* stream,
+void RendererImpl::OnStreamStatusChanged(DemuxerStream* stream,
                                          bool enabled,
                                          base::TimeDelta time) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(stream);
   bool video = (stream->type() == DemuxerStream::VIDEO);
   DVLOG(1) << __func__ << (video ? " video" : " audio") << " stream=" << stream
-           << " enabled=" << stream->enabled() << " time=" << time.InSecondsF();
+           << " enabled=" << enabled << " time=" << time.InSecondsF();
   if ((state_ != STATE_PLAYING) || (audio_ended_ && video_ended_))
     return;
   if (stream->type() == DemuxerStream::VIDEO) {
     DCHECK(video_renderer_);
-    if (restarting_video_)
+    if (restarting_video_) {
+      DVLOG(3) << __func__ << ": postponed stream " << stream
+               << " status change handling.";
+      task_runner_->PostDelayedTask(
+          FROM_HERE, base::Bind(&RendererImpl::OnStreamStatusChanged,
+                                weak_this_, stream, enabled, time),
+          base::TimeDelta::FromMilliseconds(kStreamStatusHandlingDelayMs));
       return;
+    }
     restarting_video_ = true;
     video_renderer_->Flush(
         base::Bind(&RendererImpl::RestartVideoRenderer, weak_this_, time));
   } else if (stream->type() == DemuxerStream::AUDIO) {
     DCHECK(audio_renderer_);
     DCHECK(time_source_);
-    if (restarting_audio_)
+    if (restarting_audio_) {
+      DVLOG(3) << __func__ << ": postponed stream " << stream
+               << " status change handling.";
+      task_runner_->PostDelayedTask(
+          FROM_HERE, base::Bind(&RendererImpl::OnStreamStatusChanged,
+                                weak_this_, stream, enabled, time),
+          base::TimeDelta::FromMilliseconds(kStreamStatusHandlingDelayMs));
       return;
+    }
     restarting_audio_ = true;
     // Stop ticking (transition into paused state) in audio renderer before
     // calling Flush, since after Flush we are going to restart playback by
     // calling audio renderer StartPlaying which would fail in playing state.
     if (time_ticking_) {
       time_ticking_ = false;
       time_source_->StopTicking();
     }
     audio_renderer_->Flush(
         base::Bind(&RendererImpl::RestartAudioRenderer, weak_this_, time));
@@ skipping 130 matching lines @@
 
   DemuxerStream* audio_stream =
       demuxer_stream_provider_->GetStream(DemuxerStream::AUDIO);
   if (!audio_stream) {
     audio_renderer_.reset();
     task_runner_->PostTask(FROM_HERE, base::Bind(done_cb, PIPELINE_OK));
     return;
   }
 
   audio_stream->SetStreamStatusChangeCB(base::Bind(
-      &RendererImpl::RestartStreamPlayback, weak_this_, audio_stream));
+      &RendererImpl::OnStreamStatusChanged, weak_this_, audio_stream));
 
   audio_renderer_client_.reset(
       new RendererClientInternal(DemuxerStream::AUDIO, this));
   // Note: After the initialization of a renderer, error events from it may
   // happen at any time and all future calls must guard against STATE_ERROR.
   audio_renderer_->Initialize(audio_stream, cdm_context_,
                               audio_renderer_client_.get(), done_cb);
 }
 
 void RendererImpl::OnAudioRendererInitializeDone(PipelineStatus status) {
@@ skipping 28 matching lines @@
 
   DemuxerStream* video_stream =
       demuxer_stream_provider_->GetStream(DemuxerStream::VIDEO);
   if (!video_stream) {
     video_renderer_.reset();
     task_runner_->PostTask(FROM_HERE, base::Bind(done_cb, PIPELINE_OK));
     return;
   }
 
   video_stream->SetStreamStatusChangeCB(base::Bind(
-      &RendererImpl::RestartStreamPlayback, weak_this_, video_stream));
+      &RendererImpl::OnStreamStatusChanged, weak_this_, video_stream));
 
   video_renderer_client_.reset(
       new RendererClientInternal(DemuxerStream::VIDEO, this));
   video_renderer_->Initialize(
       video_stream, cdm_context_, video_renderer_client_.get(),
       base::Bind(&RendererImpl::GetWallClockTimes, base::Unretained(this)),
       done_cb);
 }
 
 void RendererImpl::OnVideoRendererInitializeDone(PipelineStatus status) {
@@ skipping 391 matching lines @@
   DCHECK(task_runner_->BelongsToCurrentThread());
   client_->OnVideoNaturalSizeChange(size);
 }
 
 void RendererImpl::OnVideoOpacityChange(bool opaque) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   client_->OnVideoOpacityChange(opaque);
 }
 
 }  // namespace media