Reduce CPU usage in test::FrameGenerator::SquareGenerator.

webrtc/test/frame_generator.cc

 /*
  *  Copyright (c) 2013 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.
  */
 #include "webrtc/test/frame_generator.h"
@@ skipping 65 matching lines @@
           x_(random_generator_.Rand(0, width)),
           y_(random_generator_.Rand(0, height)),
           length_(random_generator_.Rand(1, width > 4 ? width / 4 : 1)),
           yuv_y_(random_generator_.Rand(0, 255)),
           yuv_u_(random_generator_.Rand(0, 255)),
           yuv_v_(random_generator_.Rand(0, 255)) {}
 
     void Draw(const rtc::scoped_refptr<I420Buffer>& buffer) {
       x_ = (x_ + random_generator_.Rand(0, 4)) % (buffer->width() - length_);
       y_ = (y_ + random_generator_.Rand(0, 4)) % (buffer->height() - length_);
-      for (int x = x_; x < x_ + length_; ++x) {
         for (int y = y_; y < y_ + length_; ++y) {
-          uint8_t* pos_y = (buffer->MutableDataY() + x + y * buffer->StrideY());
-          *pos_y = yuv_y_;
+          uint8_t* pos_y =
+              (buffer->MutableDataY() + x_ + y * buffer->StrideY());
+          memset(pos_y, yuv_y_, length_);
+        }
+
+        for (int y = y_; y < y_ + length_; y = y + 2) {
           uint8_t* pos_u =
-              (buffer->MutableDataU() + x / 2 + y / 2 * buffer->StrideU());
-          *pos_u = yuv_u_;
+              (buffer->MutableDataU() + x_ / 2 + y / 2 * buffer->StrideU());
+          memset(pos_u, yuv_u_, length_ / 2);
           uint8_t* pos_v =
-              (buffer->MutableDataV() + x / 2 + y / 2 * buffer->StrideV());
-          *pos_v = yuv_v_;
+              (buffer->MutableDataV() + x_ / 2 + y / 2 * buffer->StrideV());
+          memset(pos_v, yuv_v_, length_ / 2);
         }
-      }
     }
 
    private:
     Random random_generator_;
     int x_;
     int y_;
     const int length_;
     const uint8_t yuv_y_;
     const uint8_t yuv_u_;
     const uint8_t yuv_v_;
@@ skipping 255 matching lines @@
     files.push_back(file);
   }
 
   return std::unique_ptr<FrameGenerator>(new ScrollingImageFrameGenerator(
       clock, files, source_width, source_height, target_width, target_height,
       scroll_time_ms, pause_time_ms));
 }
 
 }  // namespace test
 }  // namespace webrtc