Add a frame generator that allows scrolling images

webrtc/test/frame_generator.h

 /*
  *  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.
  */
 #ifndef WEBRTC_COMMON_VIDEO_TEST_FRAME_GENERATOR_H_
 #define WEBRTC_COMMON_VIDEO_TEST_FRAME_GENERATOR_H_
 
 #include <string>
 #include <vector>
 
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"
 
 namespace webrtc {
+class Clock;
 namespace test {
 
 class FrameGenerator {
  public:
   FrameGenerator() {}
   virtual ~FrameGenerator() {}
 
   // Returns video frame that remains valid until next call.
   virtual VideoFrame* NextFrame() = 0;
 
   // Creates a test frame generator that creates fully saturated frames with
   // varying U, V values over time.
   static FrameGenerator* CreateChromaGenerator(size_t width, size_t height);
 
   // Creates a frame generator that repeatedly plays a set of yuv files.
   // The frame_repeat_count determines how many times each frame is shown,
   // with 1 = show each frame once, etc.
   static FrameGenerator* CreateFromYuvFile(std::vector<std::string> files,
                                            size_t width,
                                            size_t height,
                                            int frame_repeat_count);
+
+  // Creates a frame generator which takes a set of yuv files (wrapping a
+  // frame generator created by CreateFromYuvFile() above), but outputs frames
+  // that have been cropped to specified resolution: source_width/source_height
+  // is the size of the source images, target_width/target_height is the size of
+  // the cropped output. For each source image read, the cropped viewport will
+  // be scrolled top to bottom/left to right for scroll_tim_ms milliseconds.
+  // After that the image will stay in place for pause_time_ms milliseconds,
+  // and then this will be repeated with the next file from the input set.
+  static FrameGenerator* CreateScrollingInputFromYuvFiles(
+      Clock* clock,
+      std::vector<std::string> filenames,
+      size_t source_width,
+      size_t source_height,
+      size_t target_width,
+      size_t target_height,
+      int64_t scroll_time_ms,
+      int64_t pause_time_ms);
 };
 }  // namespace test
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_VIDEO_TEST_FRAME_GENERATOR_H_