Refactor scaling.

webrtc/common_video/include/video_frame_buffer.h

 /*
  *  Copyright (c) 2015 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 91 matching lines @@
   int StrideU() const override;
   int StrideV() const override;
 
   void* native_handle() const override;
   rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
 
   // Create a new buffer and copy the pixel data.
   static rtc::scoped_refptr<I420Buffer> Copy(
       const rtc::scoped_refptr<VideoFrameBuffer>& buffer);
 
+  // Only the most generally useful operations should be methods on
+  // this class, for more specialized operations, use
+  // MutableDataY(,U,V) to get write access.
+
+  // Crop the input buffer, then scale it to the size of this buffer.
+  void CropAndScale(const rtc::scoped_refptr<VideoFrameBuffer>& buffer,
+                    int offset_x,
+                    int offset_y,
+                    int crop_width,
+                    int crop_height);
+
+  // The common case of a center crop, when needed to maintain the
+  // same aspect ratio.
+  static void CenterCropAndScale(
+      const rtc::scoped_refptr<I420Buffer>& dst,
+      const rtc::scoped_refptr<VideoFrameBuffer>& src);
+
  protected:
   ~I420Buffer() override;
 
  private:
   const int width_;
   const int height_;
   const int stride_y_;
   const int stride_u_;
   const int stride_v_;
   const std::unique_ptr<uint8_t, AlignedFreeDeleter> data_;
@@ skipping 59 matching lines @@
   const uint8_t* const u_plane_;
   const uint8_t* const v_plane_;
   const int y_stride_;
   const int u_stride_;
   const int v_stride_;
   rtc::Callback0<void> no_longer_used_cb_;
 };
 
 // Helper function to crop |buffer| without making a deep copy. May only be used
 // for non-native frames.
 rtc::scoped_refptr<VideoFrameBuffer> ShallowCenterCrop(

[magjed_webrtc, 2016/05/30 11:58:26]

Is this unused now?

[nisse-webrtc, 2016/05/30 12:58:22]

It is! It became unused in the previous cl,
https://codereview.webrtc.org/1973873003/

I'll delete it.

     const rtc::scoped_refptr<VideoFrameBuffer>& buffer,
     int cropped_width,
     int cropped_height);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_