Add Y4mFileReader

Encapsulate logic for reading .y4m video files in a single class. We
currently have spread out logic for opening .y4m files with partial
parsing. This CL consolidates this logic into a single class with a well
defined interface.

Change-Id: Id61673b3c95a0053b30e95b4cf382e1c6b05fc30
Bug: webrtc:9642
Reviewed-on: https://webrtc-review.googlesource.com/94772
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Paulina Hensman <phensman@webrtc.org>
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24398}

rtc_tools/y4m_file_reader_unittest.cc

@@ -0,0 +1,71 @@
+/*
+ *  Copyright (c) 2018 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 "rtc_tools/y4m_file_reader.h"
+#include "test/gtest.h"
+#include "test/testsupport/fileutils.h"
+
+namespace webrtc {
+namespace test {
+
+class Y4mFileReaderTest : public ::testing::Test {
+ public:
+  void SetUp() override {
+    const std::string filename =
+        TempFilename(webrtc::test::OutputPath(), "test_video_file.y4m");
+
+    // Create simple test video of size 6x4.
+    FILE* file = fopen(filename.c_str(), "wb");
+    ASSERT_TRUE(file != nullptr);
+    fprintf(file, "YUV4MPEG2 W6 H4 F57:10 C420 dummyParam\n");
+    fprintf(file, "FRAME\n");
+
+    const int width = 6;
+    const int height = 4;
+    const int i40_size = width * height * 3 / 2;
+    for (int i = 0; i < i40_size; ++i)
+      fputc(static_cast<char>(i), file);
+    fprintf(file, "FRAME\n");
+    for (int i = 0; i < i40_size; ++i)
+      fputc(static_cast<char>(i + i40_size), file);
+    fclose(file);
+
+    // Open the newly created file.
+    video = webrtc::test::Y4mFile::Open(filename);
+    ASSERT_TRUE(video);
+  }
+
+  rtc::scoped_refptr<webrtc::test::Y4mFile> video;
+};
+
+TEST_F(Y4mFileReaderTest, TestParsingFileHeader) {
+  EXPECT_EQ(6, video->width());
+  EXPECT_EQ(4, video->height());
+  EXPECT_EQ(5.7f, video->fps());
+}
+
+TEST_F(Y4mFileReaderTest, TestParsingNumberOfFrames) {
+  EXPECT_EQ(2u, video->number_of_frames());
+}
+
+TEST_F(Y4mFileReaderTest, TestPixelContent) {
+  int cnt = 0;
+  for (const rtc::scoped_refptr<I420BufferInterface> frame : *video) {
+    for (int i = 0; i < 6 * 4; ++i, ++cnt)
+      EXPECT_EQ(cnt, frame->DataY()[i]);
+    for (int i = 0; i < 3 * 2; ++i, ++cnt)
+      EXPECT_EQ(cnt, frame->DataU()[i]);
+    for (int i = 0; i < 3 * 2; ++i, ++cnt)
+      EXPECT_EQ(cnt, frame->DataV()[i]);
+  }
+}
+
+}  // namespace test
+}  // namespace webrtc