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

webrtc/test/testsupport/metrics/video_metrics.cc

Index: webrtc/test/testsupport/metrics/video_metrics.cc
diff --git a/webrtc/test/testsupport/metrics/video_metrics.cc b/webrtc/test/testsupport/metrics/video_metrics.cc
index 75bbc61fce0e55309175b93a9a1c2195001663e9..3013b6135593995b37ecb41ccfb2f8547c85ba8c 100644
--- a/webrtc/test/testsupport/metrics/video_metrics.cc
+++ b/webrtc/test/testsupport/metrics/video_metrics.cc
@@ -17,6 +17,7 @@
 #include <memory>
 
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
+#include "webrtc/test/frame_utils.h"
 #include "webrtc/video_frame.h"
 #include "libyuv/convert.h"
 
@@ -110,44 +111,17 @@ int CalculateMetrics(VideoMetricsType video_metrics_type,
   int frame_number = 0;
 
   // Read reference and test frames.
-  const size_t frame_length = 3 * width * height >> 1;
-  rtc::scoped_refptr<I420Buffer> ref_i420_buffer;
-  rtc::scoped_refptr<I420Buffer> test_i420_buffer;
-  std::unique_ptr<uint8_t[]> ref_buffer(new uint8_t[frame_length]);
-  std::unique_ptr<uint8_t[]> test_buffer(new uint8_t[frame_length]);
-
-  // Set decoded image parameters.
-  int half_width = (width + 1) / 2;
-  ref_i420_buffer =
-      I420Buffer::Create(width, height, width, half_width, half_width);
-  test_i420_buffer =
-      I420Buffer::Create(width, height, width, half_width, half_width);
-
-  // TODO(nisse): Have a frame reader in one place. And read directly
-  // into the planes of an I420Buffer, the extra copying below is silly.
-  size_t ref_bytes = fread(ref_buffer.get(), 1, frame_length, ref_fp);
-  size_t test_bytes = fread(test_buffer.get(), 1, frame_length, test_fp);
-  while (ref_bytes == frame_length && test_bytes == frame_length) {
-    // Converting from buffer to plane representation.
-    size_t size_y = width * height;
-    size_t size_uv = half_width * ((height + 1) / 2);
-    libyuv::I420Copy(
-        ref_buffer.get(), width,
-        ref_buffer.get() + size_y, half_width,
-        ref_buffer.get() + size_y + size_uv, half_width,
-        ref_i420_buffer->MutableDataY(), ref_i420_buffer->StrideY(),
-        ref_i420_buffer->MutableDataU(), ref_i420_buffer->StrideU(),
-        ref_i420_buffer->MutableDataV(), ref_i420_buffer->StrideV(),
-        width, height);
-
-    libyuv::I420Copy(
-        test_buffer.get(), width,
-        test_buffer.get() + size_y, half_width,
-        test_buffer.get() + size_y + size_uv, half_width,
-        test_i420_buffer->MutableDataY(), test_i420_buffer->StrideY(),
-        test_i420_buffer->MutableDataU(), test_i420_buffer->StrideU(),
-        test_i420_buffer->MutableDataV(), test_i420_buffer->StrideV(),
-        width, height);
+  for (;;) {
+    rtc::scoped_refptr<I420Buffer> ref_i420_buffer(
+        test::ReadI420Buffer(width, height, ref_fp));
+    if (!ref_i420_buffer)
+      break;
+
+    rtc::scoped_refptr<I420Buffer> test_i420_buffer(
+        test::ReadI420Buffer(width, height, test_fp));
+
+    if (!test_i420_buffer)
+      break;
 
     switch (video_metrics_type) {
       case kPSNR:
@@ -166,8 +140,6 @@ int CalculateMetrics(VideoMetricsType video_metrics_type,
         break;
     }
     frame_number++;
-    ref_bytes = fread(ref_buffer.get(), 1, frame_length, ref_fp);
-    test_bytes = fread(test_buffer.get(), 1, frame_length, test_fp);
   }
   int return_code = 0;
   if (frame_number == 0) {