New helper function test::ReadI420Buffer, refactor FrameReader to use it.

webrtc/test/frame_utils.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.
  */
 
@@ skipping 54 matching lines @@
                     f1->StrideY(), f2->StrideY(),
                     f1->width(), f1->height()) &&
          EqualPlane(f1->DataU(), f2->DataU(),
                     f1->StrideU(), f2->StrideU(),
                     half_width, half_height) &&
          EqualPlane(f1->DataV(), f2->DataV(),
                     f1->StrideV(), f2->StrideV(),
                     half_width, half_height);
 }
 
+rtc::scoped_refptr<I420Buffer> ReadI420Buffer(int width, int height, FILE *f) {
+  int half_width = (width + 1) / 2;
+  rtc::scoped_refptr<I420Buffer> buffer(
+      // Explicit stride, no padding between rows.
+      I420Buffer::Create(width, height, width, half_width, half_width));
+  size_t size_y = static_cast<size_t>(width) * height;
+  size_t size_uv = static_cast<size_t>(half_width) * ((height + 1) / 2);
+
+  if (fread(buffer->MutableDataY(), 1, size_y, f) < size_y)
+    return nullptr;
+  if (fread(buffer->MutableDataU(), 1, size_uv, f) < size_uv)
+    return nullptr;
+  if (fread(buffer->MutableDataV(), 1, size_uv, f) < size_uv)
+    return nullptr;
+  return buffer;
+}
+
 }  // namespace test
 }  // namespace webrtc