Refactor scaling.

webrtc/modules/video_coding/utility/quality_scaler.cc

Index: webrtc/modules/video_coding/utility/quality_scaler.cc
diff --git a/webrtc/modules/video_coding/utility/quality_scaler.cc b/webrtc/modules/video_coding/utility/quality_scaler.cc
index bb60ee036e381dc9762e3b9a030acd257582eed5..6fe1c66490d3c2cbc6a358408d484c1d18606489 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler.cc
@@ -7,6 +7,10 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+
+// TODO(nisse): Switch to RTC_CHECK (or RTC_DCHECK) ?
+#include <assert.h>
+
 #include "webrtc/modules/video_coding/utility/quality_scaler.h"
 
 namespace webrtc {
@@ -94,7 +98,7 @@ void QualityScaler::ReportDroppedFrame() {
   framedrop_percent_.AddSample(100);
 }
 
-void QualityScaler::OnEncodeFrame(const VideoFrame& frame) {
+void QualityScaler::OnEncodeFrame(int width, int height) {
   // Should be set through InitEncode -> Should be set by now.
   assert(low_qp_threshold_ >= 0);
   assert(num_samples_upscale_ > 0);
@@ -113,34 +117,27 @@ void QualityScaler::OnEncodeFrame(const VideoFrame& frame) {
              avg_qp <= low_qp_threshold_) {
     AdjustScale(true);
   }
-  UpdateTargetResolution(frame.width(), frame.height());
+  UpdateTargetResolution(width, height);
 }
 
 QualityScaler::Resolution QualityScaler::GetScaledResolution() const {
   return res_;
 }
 
-const VideoFrame& QualityScaler::GetScaledFrame(const VideoFrame& frame) {
+rtc::scoped_refptr<VideoFrameBuffer> QualityScaler::GetScaledFrame(
+    const rtc::scoped_refptr<VideoFrameBuffer>& frame) {
   Resolution res = GetScaledResolution();
-  if (res.width == frame.width())
-    return frame;
+  int src_width = frame->width();
+  int src_height = frame->height();
 
-  scaler_.Set(frame.width(), frame.height(), res.width, res.height, kI420,
-              kI420, kScaleBox);
-  if (scaler_.Scale(frame, &scaled_frame_) != 0)
+  if (res.width == src_width && res.height == src_height)
     return frame;
+  rtc::scoped_refptr<I420Buffer> scaled =
+      pool_.CreateBuffer(res.width, res.height);
+
+  I420Buffer::CenterCropAndScale(scaled, frame);
 
-  // TODO(perkj): Refactor the scaler to not own |scaled_frame|. VideoFrame are
-  // just thin wrappers so instead the scaler should return a
-  // rtc::scoped_refptr<VideoFrameBuffer> and a new VideoFrame be created with
-  // the meta data from |frame|. That way we would not have to set all these
-  // meta data.
-  scaled_frame_.set_ntp_time_ms(frame.ntp_time_ms());
-  scaled_frame_.set_timestamp(frame.timestamp());
-  scaled_frame_.set_render_time_ms(frame.render_time_ms());
-  scaled_frame_.set_rotation(frame.rotation());
-
-  return scaled_frame_;
+  return scaled;
 }
 
 void QualityScaler::UpdateTargetResolution(int frame_width, int frame_height) {