Provide a Chrome-owned buffer to FFmpeg for video decoding, instead of

media/base/video_frame.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_VIDEO_FRAME_H_
 #define MEDIA_BASE_VIDEO_FRAME_H_
 
 #include "base/callback.h"
 #include "base/md5.h"
 #include "media/base/buffers.h"
@@ skipping 101 matching lines @@
     return duration_;
   }
   void SetDuration(const base::TimeDelta& duration) {
     duration_ = duration;
   }
 
   // Used to keep a running hash of seen frames.  Expects an initialized MD5
   // context.  Calls MD5Update with the context and the contents of the frame.
   void HashFrameForTesting(base::MD5Context* context);
 
- private:
-  friend class base::RefCountedThreadSafe<VideoFrame>;
-  // Clients must use the static CreateFrame() method to create a new frame.
   VideoFrame(Format format,
              size_t video_width,
              size_t video_height,
              base::TimeDelta timestamp,
              base::TimeDelta duration);
+  int AllocateAlignedWithStrides(int strides[], int aligned_h);

[Ami GONE FROM CHROMIUM, 2012/05/26 22:52:34]

This change (ctor public, add public allocate method) seems strange.
Why wouldn't you bury the alignment details inside the CreateFrame public entry
point?
For that matter, what code path wants to allocate *unaligned* memory?  I suspect
you can drop all changes to this file from this CL (restricting your change to
the .cc file).

+
+private:
+  friend class base::RefCountedThreadSafe<VideoFrame>;
   virtual ~VideoFrame();
 
   // Used internally by CreateFrame().
   void AllocateRGB(size_t bytes_per_pixel);
   void AllocateYUV();
 
   // Used to DCHECK() plane parameters.
   bool IsValidPlane(size_t plane) const;
 
   // Frame format.
   Format format_;
 
   // Width and height of surface.
   size_t width_;
   size_t height_;
 
   // Array of strides for each plane, typically greater or equal to the width
   // of the surface divided by the horizontal sampling period.  Note that
   // strides can be negative.
   int32 strides_[kMaxPlanes];
 
   // Array of data pointers to each plane.
   uint8* data_[kMaxPlanes];
+  int is_aligned_alloc_;
 
   // Native texture ID, if this is a NATIVE_TEXTURE frame.
   uint32 texture_id_;
   uint32 texture_target_;
   base::Closure texture_no_longer_needed_;
 
   base::TimeDelta timestamp_;
   base::TimeDelta duration_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoFrame);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_FRAME_H_