New static I420Buffer::Rotate method, to replace GetCopyWithRotationApplied.

webrtc/common_video/video_frame_buffer.cc

 /*
  *  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 28 matching lines @@
   RTC_NOTREACHED();
   return nullptr;
 }
 uint8_t* VideoFrameBuffer::MutableDataV() {
   RTC_NOTREACHED();
   return nullptr;
 }
 
 VideoFrameBuffer::~VideoFrameBuffer() {}
 
+// static
+rtc::scoped_refptr<VideoFrameBuffer> VideoFrameBuffer::Rotate(
+    const rtc::scoped_refptr<VideoFrameBuffer>& src,
+    VideoRotation rotation) {

[perkj_webrtc, 2016/08/26 15:22:17]

please dcheck that src->DataY and U and V returns a pointer!=nullptr. This may
be a native handle for all we know. 

+  if (rotation == webrtc::kVideoRotation_0) {
+    return src;
+  }
+
+  int rotated_width = src->width();
+  int rotated_height = src->height();
+  if (rotation == webrtc::kVideoRotation_90 ||
+      rotation == webrtc::kVideoRotation_270) {
+    std::swap(rotated_width, rotated_height);
+  }
+
+  rtc::scoped_refptr<webrtc::I420Buffer> buffer =
+      I420Buffer::Create(rotated_width, rotated_height);
+
+  int res = libyuv::I420Rotate(
+      src->DataY(), src->StrideY(),
+      src->DataU(), src->StrideU(),
+      src->DataV(), src->StrideV(),
+      buffer->MutableDataY(), buffer->StrideY(), buffer->MutableDataU(),
+      buffer->StrideU(), buffer->MutableDataV(), buffer->StrideV(),
+      src->width(), src->height(),
+      static_cast<libyuv::RotationMode>(rotation));
+  RTC_DCHECK_EQ(res, 0);
+
+  return buffer;
+}
+
 I420Buffer::I420Buffer(int width, int height)
     : I420Buffer(width, height, width, (width + 1) / 2, (width + 1) / 2) {
 }
 
 I420Buffer::I420Buffer(int width,
                        int height,
                        int stride_y,
                        int stride_u,
                        int stride_v)
     : width_(width),
@@ skipping 279 matching lines @@
 void* WrappedI420Buffer::native_handle() const {
   return nullptr;
 }
 
 rtc::scoped_refptr<VideoFrameBuffer> WrappedI420Buffer::NativeToI420Buffer() {
   RTC_NOTREACHED();
   return nullptr;
 }
 
 }  // namespace webrtc