iOS: Optimize video scaling and cropping

webrtc/common_video/libyuv/libyuv_unittest.cc

 /*
  *  Copyright (c) 2012 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 <math.h>
 #include <string.h>
 
 #include <memory>
 
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/test/frame_utils.h"
+#include "webrtc/test/gmock.h"
 #include "webrtc/test/gtest.h"
 #include "webrtc/test/testsupport/fileutils.h"
 #include "webrtc/video_frame.h"
 
 namespace webrtc {
 
 namespace {
 void Calc16ByteAlignedStride(int width, int* stride_y, int* stride_uv) {
   *stride_y = 16 * ((width + 15) / 16);
   *stride_uv = 16 * ((width + 31) / 32);
@@ skipping 218 matching lines @@
   EXPECT_EQ(0, ConvertToI420(kI420, orig_buffer, 0, 0, width_, height_,
                              0, kVideoRotation_270,
                              rotated_res_i420_buffer.get()));
   rotated_res_i420_buffer = I420Buffer::Create(
       width_, height_, width_, (width_ + 1) / 2, (width_ + 1) / 2);
   EXPECT_EQ(0, ConvertToI420(kI420, orig_buffer, 0, 0, width_, height_,
                              0, kVideoRotation_180,
                              rotated_res_i420_buffer.get()));
 }
 
+static uint8_t Average(int a, int b, int c, int d) {
+  return (a + b + c + d + 2) / 4;
+}
+
+TEST_F(TestLibYuv, NV12Scale2x2to2x2) {
+  const std::vector<uint8_t> src_y = {0, 1,
+                                      2, 3};
+  const std::vector<uint8_t> src_uv = {0, 1};
+  std::vector<uint8_t> dst_y(4);
+  std::vector<uint8_t> dst_uv(2);
+
+  std::vector<uint8_t> tmp_buffer;
+  NV12Scale(&tmp_buffer,
+            src_y.data(), 2,
+            src_uv.data(), 2,
+            2, 2,
+            dst_y.data(), 2,
+            dst_uv.data(), 2,
+            2, 2);
+
+  EXPECT_THAT(dst_y, ::testing::ContainerEq(src_y));
+  EXPECT_THAT(dst_uv, ::testing::ContainerEq(src_uv));
+}
+
+TEST_F(TestLibYuv, NV12Scale4x4to2x2) {
+  const uint8_t src_y[] = { 0,  1,  2,  3,
+                            4,  5,  6,  7,
+                            8,  9, 10, 11,
+                           12, 13, 14, 15};
+  const uint8_t src_uv[] = {0, 1, 2, 3,
+                            4, 5, 6, 7};
+  std::vector<uint8_t> dst_y(4);
+  std::vector<uint8_t> dst_uv(2);
+
+  std::vector<uint8_t> tmp_buffer;
+  NV12Scale(&tmp_buffer,
+            src_y, 4,
+            src_uv, 4,
+            4, 4,
+            dst_y.data(), 2,
+            dst_uv.data(), 2,
+            2, 2);
+
+  EXPECT_THAT(dst_y, ::testing::ElementsAre(
+                         Average(0, 1, 4, 5), Average(2, 3, 6, 7),
+                         Average(8, 9, 12, 13), Average(10, 11, 14, 15)));
+  EXPECT_THAT(dst_uv,
+              ::testing::ElementsAre(Average(0, 2, 4, 6), Average(1, 3, 5, 7)));
+}
+
 }  // namespace webrtc