Revert to zero-initializing buffers for FFmpegVideoDecoder

media/base/video_frame_pool.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/base/video_frame_pool.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 
 namespace media {
 
 class VideoFramePool::PoolImpl
     : public base::RefCountedThreadSafe<VideoFramePool::PoolImpl> {
  public:
   PoolImpl();
 
-  // Returns a frame from the pool that matches the specified
-  // parameters or creates a new frame if no suitable frame exists in
-  // the pool. The pool is drained if no matching frame is found.
+  // See VideoFramePool::CreateFrame() for usage.
   scoped_refptr<VideoFrame> CreateFrame(VideoPixelFormat format,
                                         const gfx::Size& coded_size,
                                         const gfx::Rect& visible_rect,
                                         const gfx::Size& natural_size,
                                         base::TimeDelta timestamp);
 
   // Shuts down the frame pool and releases all frames in |frames_|.
   // Once this is called frames will no longer be inserted back into
   // |frames_|.
   void Shutdown();
@@ skipping 41 matching lines @@
           pool_frame->coded_size() == coded_size &&
           pool_frame->visible_rect() == visible_rect &&
           pool_frame->natural_size() == natural_size) {
         frame = pool_frame;
         frame->set_timestamp(timestamp);
         break;
       }
   }
 
   if (!frame.get()) {
-    frame = VideoFrame::CreateFrame(
-        format, coded_size, visible_rect, natural_size, timestamp);
+    frame = VideoFrame::CreateFrame(format, coded_size, visible_rect,
+                                    natural_size, timestamp);
+
+    // Zero-initialize each plane of the buffer.
+    const size_t num_planes = VideoFrame::NumPlanes(frame->format());
+    for (size_t i = 0; i < num_planes; ++i) {
+      memset(frame->data(i),
+             0,
+             VideoFrame::PlaneSize(frame->format(),
+                                   i,
+                                   frame->coded_size()).GetArea());
+    }
   }
 
   scoped_refptr<VideoFrame> wrapped_frame = VideoFrame::WrapVideoFrame(
       frame, frame->visible_rect(), frame->natural_size());
   wrapped_frame->AddDestructionObserver(
       base::Bind(&VideoFramePool::PoolImpl::FrameReleased, this, frame));
   return wrapped_frame;
 }
 
 void VideoFramePool::PoolImpl::Shutdown() {
@@ skipping 26 matching lines @@
     base::TimeDelta timestamp) {
   return pool_->CreateFrame(format, coded_size, visible_rect, natural_size,
                             timestamp);
 }
 
 size_t VideoFramePool::GetPoolSizeForTesting() const {
   return pool_->GetPoolSizeForTesting();
 }
 
 }  // namespace media