Memory copy the VideoFrame to match the requirement for HW encoders.

media/base/video_util.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_UTIL_H_
 #define MEDIA_BASE_VIDEO_UTIL_H_
 
 #include <stdint.h>
 
 #include "base/memory/ref_counted.h"
@@ skipping 79 matching lines @@
 // Fills the regions outside |region_in_frame| with black.
 MEDIA_EXPORT void CopyRGBToVideoFrame(const uint8_t* source,
                                       int stride,
                                       const gfx::Rect& region_in_frame,
                                       VideoFrame* frame);
 
 // Converts a frame with YV12A format into I420 by dropping alpha channel.
 MEDIA_EXPORT scoped_refptr<VideoFrame> WrapAsI420VideoFrame(
     const scoped_refptr<VideoFrame>& frame);
 
+// Copy I420 video frame to match the required coded size and pad it repeatly
+// with the last column / row.

[miu, 2016/04/30 00:41:14]

Comment should also mention: 1) The visible region in both frames should be
identical; 2) When/why would this function would return true or false.

[xjz, 2016/05/03 01:17:58]

Done.

+MEDIA_EXPORT bool I420CopyWithPadding(const scoped_refptr<VideoFrame> src_frame,

[miu, 2016/04/30 00:41:14]

Type of the args should be:

const VideoFrame& src_frame,  // because it's read-only and a non-null frame is
required
VideoFrame* dst_frame,  // because nothing will take ownership of dst_frame

[xjz, 2016/05/03 01:17:58]

Done.

+                                      scoped_refptr<VideoFrame> dst_frame);

[miu, 2016/04/30 00:41:14]

Consider adding WARN_UNUSED_RESULT in the function signature. This will force
callers of this function to examine the return boolean. Meaning:

  MEDIA_EXPORT bool I420CopyWithPadding(...) WARN_UNUSED_RESULT;

[xjz, 2016/05/03 01:17:59]

Done.

+
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_UTIL_H_