Move MutableDataY{,U,V} methods to I420Buffer only.

webrtc/common_video/libyuv/include/webrtc_libyuv.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 84 matching lines @@
 // Return value: 0 if OK, < 0 otherwise.
 
 int ConvertToI420(VideoType src_video_type,
                   const uint8_t* src_frame,
                   int crop_x,
                   int crop_y,
                   int src_width,
                   int src_height,
                   size_t sample_size,
                   VideoRotation rotation,
-                  VideoFrame* dst_frame);
+                  const rtc::scoped_refptr<I420Buffer>& dst_buffer);

[magjed_webrtc, 2016/08/25 11:12:56]

If dst_buffer is an output argument, you need to use a pointer to a
scoped_refptr. (Or a pointer to an I420Buffer if we will allow that).

[nisse-webrtc, 2016/08/25 11:31:35]

I think the const is ok here; the scoped_refptr itself is not modified in any
way, but the object it points to have it's pixel buffers overwritten.

[magjed_webrtc, 2016/08/25 11:49:08]

Yes, using const here will compile, but according to the style guide you need to
use a pointer to a scoped_refptr if it's an output.

[nisse-webrtc, 2016/08/25 12:38:40]

I'll do that then. That makes sense in some way. But it gets awkward to
dereference, like

  int dst_width = (*dst_buffer)->width();

I think I'll count that as one point for using a raw pointer argument instead.

 
 // Convert From I420
 // Input:
 //   - src_frame        : Reference to a source frame.
 //   - dst_video_type   : Type of output video.
 //   - dst_sample_size  : Required only for the parsing of MJPG.
 //   - dst_frame        : Pointer to a destination frame.
 // Return value: 0 if OK, < 0 otherwise.
 // It is assumed that source and destination have equal height.
 int ConvertFromI420(const VideoFrame& src_frame,
                     VideoType dst_video_type,
                     int dst_sample_size,
                     uint8_t* dst_frame);
 
 // Compute PSNR for an I420 frame (all planes).
 // Returns the PSNR in decibel, to a maximum of kInfinitePSNR.
 double I420PSNR(const VideoFrame* ref_frame, const VideoFrame* test_frame);
+double I420PSNR(const rtc::scoped_refptr<VideoFrameBuffer>& ref_buffer,
+                const rtc::scoped_refptr<VideoFrameBuffer>& test_buffer);
 // Compute SSIM for an I420 frame (all planes).
 double I420SSIM(const VideoFrame* ref_frame, const VideoFrame* test_frame);
+double I420SSIM(const rtc::scoped_refptr<VideoFrameBuffer>& ref_buffer,
+                const rtc::scoped_refptr<VideoFrameBuffer>& test_buffer);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_VIDEO_LIBYUV_INCLUDE_WEBRTC_LIBYUV_H_