Add optional visualization file writers to VideoProcessor tests.

webrtc/test/testsupport/frame_writer.h

 /*
  *  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.
  */
 
@@ skipping 24 matching lines @@
   virtual bool WriteFrame(uint8_t* frame_buffer) = 0;
 
   // Closes the output file if open. Essentially makes this class impossible
   // to use anymore. Will also be invoked by the destructor.
   virtual void Close() = 0;
 
   // Frame length in bytes of a single frame image.
   virtual size_t FrameLength() = 0;
 };
 
-class FrameWriterImpl : public FrameWriter {
+// Writes raw I420 frames in sequence.
+class YuvFrameWriterImpl : public FrameWriter {
  public:
   // Creates a file handler. The input file is assumed to exist and be readable
   // and the output file must be writable.
   // Parameters:
   //   output_filename         The file to write. Will be overwritten if already
   //                           existing.
-  //   frame_length_in_bytes   The size of each frame.
-  //                           For YUV: 3*width*height/2
-  FrameWriterImpl(std::string output_filename, size_t frame_length_in_bytes);
-  ~FrameWriterImpl() override;
+  //   width, height           Size of each frame to read.
+  YuvFrameWriterImpl(std::string output_filename, int width, int height);
+  ~YuvFrameWriterImpl() override;
   bool Init() override;
   bool WriteFrame(uint8_t* frame_buffer) override;
   void Close() override;
   size_t FrameLength() override;
 
+ protected:
+  const std::string output_filename_;
+  size_t frame_length_in_bytes_;
+  const int width_;
+  const int height_;
+  FILE* output_file_;
+};
+
+// Writes raw I420 frames in sequence, but with Y4M file and frame headers for
+// more convenient playback in external media players.
+class Y4mFrameWriterImpl : public YuvFrameWriterImpl {
+ public:
+  Y4mFrameWriterImpl(std::string output_filename,
+                     int width,
+                     int height,
+                     int frame_rate);
+  ~Y4mFrameWriterImpl() override;
+  bool Init() override;
+  bool WriteFrame(uint8_t* frame_buffer) override;
+
  private:
-  std::string output_filename_;
-  size_t frame_length_in_bytes_;
-  FILE* output_file_;
+  const int frame_rate_;
 };
 
 }  // namespace test
 }  // namespace webrtc
 
 #endif  // WEBRTC_TEST_TESTSUPPORT_FRAME_WRITER_H_