Change the TimeSource interface to return wallclock time for video.

media/renderers/video_renderer_impl.cc

 // Copyright 2013 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/video_renderer_impl.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/platform_thread.h"
+#include "base/time/default_tick_clock.h"
 #include "base/trace_event/trace_event.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/buffers.h"
 #include "media/base/limits.h"
 #include "media/base/pipeline.h"
 #include "media/base/video_frame.h"
 
 namespace media {
 
 VideoRendererImpl::VideoRendererImpl(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     ScopedVector<VideoDecoder> decoders,
     bool drop_frames,
     const scoped_refptr<MediaLog>& media_log)
     : task_runner_(task_runner),
       video_frame_stream_(
           new VideoFrameStream(task_runner, decoders.Pass(), media_log)),
       low_delay_(false),
       received_end_of_stream_(false),
       rendered_end_of_stream_(false),
       frame_available_(&lock_),
       state_(kUninitialized),
       thread_(),
       pending_read_(false),
       drop_frames_(drop_frames),
       buffering_state_(BUFFERING_HAVE_NOTHING),
-      last_timestamp_(kNoTimestamp()),
-      last_painted_timestamp_(kNoTimestamp()),
       frames_decoded_(0),
       frames_dropped_(0),
       is_shutting_down_(false),
+      tick_clock_(new base::DefaultTickClock()),
       weak_factory_(this) {
 }
 
 VideoRendererImpl::~VideoRendererImpl() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   {
     base::AutoLock auto_lock(lock_);
     is_shutting_down_ = true;
     frame_available_.Signal();
@@ skipping 48 matching lines @@
 
 void VideoRendererImpl::Initialize(
     DemuxerStream* stream,
     const PipelineStatusCB& init_cb,
     const SetDecryptorReadyCB& set_decryptor_ready_cb,
     const StatisticsCB& statistics_cb,
     const BufferingStateCB& buffering_state_cb,
     const PaintCB& paint_cb,
     const base::Closure& ended_cb,
     const PipelineStatusCB& error_cb,
-    const TimeDeltaCB& get_time_cb,
+    const WallClockTimeCB& wall_clock_time_cb,
     const base::Closure& waiting_for_decryption_key_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   base::AutoLock auto_lock(lock_);
   DCHECK(stream);
   DCHECK_EQ(stream->type(), DemuxerStream::VIDEO);
   DCHECK(!init_cb.is_null());
   DCHECK(!statistics_cb.is_null());
   DCHECK(!buffering_state_cb.is_null());
   DCHECK(!paint_cb.is_null());
   DCHECK(!ended_cb.is_null());
-  DCHECK(!get_time_cb.is_null());
+  DCHECK(!wall_clock_time_cb.is_null());
   DCHECK_EQ(kUninitialized, state_);
 
   low_delay_ = (stream->liveness() == DemuxerStream::LIVENESS_LIVE);
 
   // Always post |init_cb_| because |this| could be destroyed if initialization
   // failed.
   init_cb_ = BindToCurrentLoop(init_cb);
 
   statistics_cb_ = statistics_cb;
   buffering_state_cb_ = buffering_state_cb;
   paint_cb_ = paint_cb,
   ended_cb_ = ended_cb;
   error_cb_ = error_cb;
-  get_time_cb_ = get_time_cb;
+  wall_clock_time_cb_ = wall_clock_time_cb;
   state_ = kInitializing;
 
   video_frame_stream_->Initialize(
       stream, base::Bind(&VideoRendererImpl::OnVideoFrameStreamInitialized,
                          weak_factory_.GetWeakPtr()),
       set_decryptor_ready_cb, statistics_cb, waiting_for_decryption_key_cb);
 }
 
 void VideoRendererImpl::CreateVideoThread() {
   // This may fail and cause a crash if there are too many threads created in
@@ skipping 53 matching lines @@
     // Thread exit condition.
     if (is_shutting_down_)
       return;
 
     // Remain idle as long as we're not playing.
     if (state_ != kPlaying || buffering_state_ != BUFFERING_HAVE_ENOUGH) {
       UpdateStatsAndWait_Locked(kIdleTimeDelta);
       continue;
     }
 
-    base::TimeDelta now = get_time_cb_.Run();
+    base::TimeTicks now = tick_clock_->NowTicks();
 
     // Remain idle until we have the next frame ready for rendering.
     if (ready_frames_.empty()) {
       if (received_end_of_stream_) {
         if (!rendered_end_of_stream_) {
           rendered_end_of_stream_ = true;
           task_runner_->PostTask(FROM_HERE, ended_cb_);
         }
-      } else if (last_painted_timestamp_ != kNoTimestamp() &&
-                 now - last_painted_timestamp_ >= kTimeToDeclareHaveNothing) {
+      } else if (!last_painted_time_.is_null() &&
+                 now - last_painted_time_ >= kTimeToDeclareHaveNothing) {
         buffering_state_ = BUFFERING_HAVE_NOTHING;
         task_runner_->PostTask(
             FROM_HERE, base::Bind(buffering_state_cb_, BUFFERING_HAVE_NOTHING));
       }
 
       UpdateStatsAndWait_Locked(kIdleTimeDelta);
       continue;
     }
 
-    base::TimeDelta target_paint_timestamp = ready_frames_.front()->timestamp();
-    base::TimeDelta latest_paint_timestamp;
+    base::TimeTicks target_paint_time =
+        wall_clock_time_cb_.Run(ready_frames_.front()->timestamp());
+
+    // If media time has stopped, don't attempt to paint any more frames.
+    if (target_paint_time.is_null()) {
+      UpdateStatsAndWait_Locked(kIdleTimeDelta);
+      continue;
+    }
+
+    base::TimeTicks latest_possible_paint_time;
 
     // Deadline is defined as the duration between this frame and the next
     // frame, using the delta between this frame and the previous frame as the
     // assumption for frame duration.
     //
     // TODO(scherkus): This can be vastly improved. Use a histogram to measure
     // the accuracy of our frame timing code. http://crbug.com/149829
-    if (last_timestamp_ == kNoTimestamp()) {
-      latest_paint_timestamp = base::TimeDelta::Max();
+    if (last_media_time_.is_null()) {
+      latest_possible_paint_time = now;
     } else {
-      base::TimeDelta duration = target_paint_timestamp - last_timestamp_;
-      latest_paint_timestamp = target_paint_timestamp + duration;
+      base::TimeDelta duration = target_paint_time - last_media_time_;
+      latest_possible_paint_time = target_paint_time + duration;
     }
 
     // Remain idle until we've reached our target paint window.
-    if (now < target_paint_timestamp) {
+    if (now < target_paint_time) {
       UpdateStatsAndWait_Locked(
-          std::min(target_paint_timestamp - now, kIdleTimeDelta));
+          std::min(target_paint_time - now, kIdleTimeDelta));
       continue;
     }
 
-    if (ready_frames_.size() > 1 && now > latest_paint_timestamp &&
+    if (ready_frames_.size() > 1 && now > latest_possible_paint_time &&
         drop_frames_) {
       DropNextReadyFrame_Locked();
       continue;
     }
 
     // Congratulations! You've made it past the video frame timing gauntlet.
     //
     // At this point enough time has passed that the next frame that ready for
     // rendering.
     PaintNextReadyFrame_Locked();
   }
 }
 
+void VideoRendererImpl::SetTickClockForTesting(
+    scoped_ptr<base::TickClock> tick_clock) {
+  tick_clock_.swap(tick_clock);
+}
+
 void VideoRendererImpl::PaintNextReadyFrame_Locked() {
   lock_.AssertAcquired();
 
   scoped_refptr<VideoFrame> next_frame = ready_frames_.front();
   ready_frames_.pop_front();
   frames_decoded_++;
 
-  last_timestamp_ = next_frame->timestamp();
-  last_painted_timestamp_ = next_frame->timestamp();
+  last_media_time_ = last_painted_time_ =
+      wall_clock_time_cb_.Run(next_frame->timestamp());
 
   paint_cb_.Run(next_frame);
 
   task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&VideoRendererImpl::AttemptRead, weak_factory_.GetWeakPtr()));
 }
 
 void VideoRendererImpl::DropNextReadyFrame_Locked() {
   TRACE_EVENT0("media", "VideoRendererImpl:frameDropped");
 
   lock_.AssertAcquired();
 
-  last_timestamp_ = ready_frames_.front()->timestamp();
+  last_media_time_ =
+      wall_clock_time_cb_.Run(ready_frames_.front()->timestamp());
+
   ready_frames_.pop_front();
   frames_decoded_++;
   frames_dropped_++;
 
   task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&VideoRendererImpl::AttemptRead, weak_factory_.GetWeakPtr()));
 }
 
 void VideoRendererImpl::FrameReady(VideoFrameStream::Status status,
@@ skipping 120 matching lines @@
 void VideoRendererImpl::OnVideoFrameStreamResetDone() {
   base::AutoLock auto_lock(lock_);
   DCHECK_EQ(kFlushing, state_);
   DCHECK(!pending_read_);
   DCHECK(ready_frames_.empty());
   DCHECK(!received_end_of_stream_);
   DCHECK(!rendered_end_of_stream_);
   DCHECK_EQ(buffering_state_, BUFFERING_HAVE_NOTHING);
 
   state_ = kFlushed;
-  last_timestamp_ = kNoTimestamp();
-  last_painted_timestamp_ = kNoTimestamp();
+  last_media_time_ = last_painted_time_ = base::TimeTicks();
   base::ResetAndReturn(&flush_cb_).Run();
 }
 
 void VideoRendererImpl::UpdateStatsAndWait_Locked(
     base::TimeDelta wait_duration) {
   lock_.AssertAcquired();
   DCHECK_GE(frames_decoded_, 0);
   DCHECK_LE(frames_dropped_, frames_decoded_);
 
   if (frames_decoded_) {
     PipelineStatistics statistics;
     statistics.video_frames_decoded = frames_decoded_;
     statistics.video_frames_dropped = frames_dropped_;
     task_runner_->PostTask(FROM_HERE, base::Bind(statistics_cb_, statistics));
 
     frames_decoded_ = 0;
     frames_dropped_ = 0;
   }
 
   frame_available_.TimedWait(wait_duration);
 }
 
 }  // namespace media