preparation for recycling buffer, patch 2

1. add ProvidesBuffer in Filter interface, not used yet.
2. add Flush stage in pipeline. not used. Render's pause work is moved to Renderer's flush().
3. merge decoder_base with ffmpeg_video_decoder. because it is shared by audio.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=55603

Review URL: http://codereview.chromium.org/3030013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@55807 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 28 insertions, 19 deletions

diff --git a/media/base/filters.h b/media/base/filters.h
index 8879233..e9d2c27 100644
--- a/media/base/filters.h
+++ b/media/base/filters.h
@@ -92,7 +92,7 @@ class MediaFilter : public base::RefCountedThreadSafe<MediaFilter> {
 
   // The pipeline has resumed playback.  Filters can continue requesting reads.
   // Filters may implement this method if they need to respond to this call.
-  // TODO(boliu): Check that callback is not NULL in sublcasses.
+  // TODO(boliu): Check that callback is not NULL in subclasses.
   virtual void Play(FilterCallback* callback) {
     DCHECK(callback);
     if (callback) {
@@ -101,10 +101,9 @@ class MediaFilter : public base::RefCountedThreadSafe<MediaFilter> {
     }
   }
 
-  // The pipeline has paused playback.  Filters should fulfill any existing read
-  // requests and then idle.  Filters may implement this method if they need to
-  // respond to this call.
-  // TODO(boliu): Check that callback is not NULL in sublcasses.
+  // The pipeline has paused playback.  Filters should stop buffer exchange.
+  // Filters may implement this method if they need to respond to this call.
+  // TODO(boliu): Check that callback is not NULL in subclasses.
   virtual void Pause(FilterCallback* callback) {
     DCHECK(callback);
     if (callback) {
@@ -113,9 +112,20 @@ class MediaFilter : public base::RefCountedThreadSafe<MediaFilter> {
     }
   }
 
+  // The pipeline has been flushed.  Filters should return buffer to owners.
+  // Filters may implement this method if they need to respond to this call.
+  // TODO(boliu): Check that callback is not NULL in subclasses.
+  virtual void Flush(FilterCallback* callback) {
+    DCHECK(callback);
+    if (callback) {
+      callback->Run();
+      delete callback;
+    }
+  }
+
   // The pipeline is being stopped either as a result of an error or because
   // the client called Stop().
-  // TODO(boliu): Check that callback is not NULL in sublcasses.
+  // TODO(boliu): Check that callback is not NULL in subclasses.
   virtual void Stop(FilterCallback* callback) {
     DCHECK(callback);
     if (callback) {
@@ -293,6 +303,9 @@ class VideoDecoder : public MediaFilter {
   // We could also pass empty pointer here to let decoder provide buffers pool.
   virtual void FillThisBuffer(scoped_refptr<VideoFrame> frame) = 0;
 
+  // Indicate whether decoder provides its own output buffers
+  virtual bool ProvidesBuffer() = 0;
+
  private:
   scoped_ptr<FillBufferDoneCallback> fill_buffer_done_callback_;
 };
diff --git a/media/base/mock_filters.h b/media/base/mock_filters.h
index ac9aab6..7f1bdaf 100644
--- a/media/base/mock_filters.h
+++ b/media/base/mock_filters.h
@@ -172,6 +172,7 @@ class MockVideoDecoder : public VideoDecoder {
                                 FilterCallback* callback));
   MOCK_METHOD0(media_format, const MediaFormat&());
   MOCK_METHOD1(FillThisBuffer, void(scoped_refptr<VideoFrame>));
+  MOCK_METHOD0(ProvidesBuffer, bool());
 
  protected:
   virtual ~MockVideoDecoder() {}
@@ -222,6 +223,7 @@ class MockVideoRenderer : public VideoRenderer {
   MOCK_METHOD2(Initialize, void(VideoDecoder* decoder,
                                 FilterCallback* callback));
   MOCK_METHOD0(HasEnded, bool());
+  MOCK_METHOD1(FillThisBufferDone, void(scoped_refptr<VideoFrame> frame));
 
  protected:
   virtual ~MockVideoRenderer() {}
diff --git a/media/base/pipeline_impl.cc b/media/base/pipeline_impl.cc
index e15492e..d8b3192 100644
--- a/media/base/pipeline_impl.cc
+++ b/media/base/pipeline_impl.cc
@@ -57,19 +57,6 @@ const char* GetThreadName() {
   }
 }
 
-// Helper function used with NewRunnableMethod to implement a (very) crude
-// blocking counter.
-//
-// TODO(scherkus): remove this as soon as Stop() is made asynchronous.
-void DecrementCounter(Lock* lock, ConditionVariable* cond_var, int* count) {
-  AutoLock auto_lock(*lock);
-  --(*count);
-  CHECK(*count >= 0);
-  if (*count == 0) {
-    cond_var->Signal();
-  }
-}
-
 }  // namespace
 
 PipelineImpl::PipelineImpl(MessageLoop* message_loop)
@@ -149,6 +136,7 @@ bool PipelineImpl::IsInitialized() const {
   AutoLock auto_lock(lock_);
   switch (state_) {
     case kPausing:
+    case kFlushing:
     case kSeeking:
     case kStarting:
     case kStarted:
@@ -382,6 +370,7 @@ void PipelineImpl::FinishInitialization() {
 // static
 bool PipelineImpl::TransientState(State state) {
   return state == kPausing ||
+         state == kFlushing ||
          state == kSeeking ||
          state == kStarting ||
          state == kStopping;
@@ -391,6 +380,8 @@ bool PipelineImpl::TransientState(State state) {
 PipelineImpl::State PipelineImpl::FindNextState(State current) {
   // TODO(scherkus): refactor InitializeTask() to make use of this function.
   if (current == kPausing)
+    return kFlushing;
+  if (current == kFlushing)
     return kSeeking;
   if (current == kSeeking)
     return kStarting;
@@ -842,6 +833,8 @@ void PipelineImpl::FilterStateTransitionTask() {
     MediaFilter* filter = filters_[filters_.size() - remaining_transitions_];
     if (state_ == kPausing) {
       filter->Pause(NewCallback(this, &PipelineImpl::OnFilterStateTransition));
+    } else if (state_ == kFlushing) {
+      filter->Flush(NewCallback(this, &PipelineImpl::OnFilterStateTransition));
     } else if (state_ == kSeeking) {
       filter->Seek(seek_timestamp_,
           NewCallback(this, &PipelineImpl::OnFilterStateTransition));
diff --git a/media/base/pipeline_impl.h b/media/base/pipeline_impl.h
index a590b47..2486f0a 100644
--- a/media/base/pipeline_impl.h
+++ b/media/base/pipeline_impl.h
@@ -118,6 +118,7 @@ class PipelineImpl : public Pipeline, public FilterHost {
     kInitVideoRenderer,
     kPausing,
     kSeeking,
+    kFlushing,
     kStarting,
     kStarted,
     kEnded,