webrtc/modules/utility/source/video_frames_queue.h

/*
 *  Copyright (c) 2011 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_MODULES_UTILITY_SOURCE_VIDEO_FRAMES_QUEUE_H_
#define WEBRTC_MODULES_UTILITY_SOURCE_VIDEO_FRAMES_QUEUE_H_

#ifdef WEBRTC_MODULE_UTILITY_VIDEO

#include <list>

#include "webrtc/common_video/interface/i420_video_frame.h"
#include "webrtc/engine_configurations.h"
#include "webrtc/typedefs.h"

namespace webrtc {

class VideoFramesQueue {
 public:
  VideoFramesQueue();
  ~VideoFramesQueue();

  // Put newFrame (last) in the queue.
  int32_t AddFrame(const I420VideoFrame& newFrame);

  // Return the most current frame. I.e. the frame with the highest
  // VideoFrame::RenderTimeMs() that is lower than
  // TickTime::MillisecondTimestamp().
  I420VideoFrame* FrameToRecord();

  // Set the render delay estimate to renderDelay ms.
  int32_t SetRenderDelay(uint32_t renderDelay);

 protected:
  // Make ptrOldFrame available for re-use. I.e. put it in the empty frames
  // queue.
  int32_t ReturnFrame(I420VideoFrame* ptrOldFrame);

 private:
  typedef std::list<I420VideoFrame*> FrameList;
  // Don't allow the buffer to expand beyond KMaxNumberOfFrames VideoFrames.
  // 300 frames correspond to 10 seconds worth of frames at 30 fps.
  enum {KMaxNumberOfFrames = 300};

  // List of VideoFrame pointers. The list is sorted in the order of when the
  // VideoFrame was inserted into the list. The first VideoFrame in the list
  // was inserted first.
  FrameList    _incomingFrames;
  // A list of frames that are free to be re-used.
  FrameList    _emptyFrames;

  // Estimated render delay.
  uint32_t _renderDelayMs;
};
}  // namespace webrtc
#endif // WEBRTC_MODULE_UTILITY_VIDEO
#endif  // WEBRTC_MODULES_UTILITY_SOURCE_VIDEO_FRAMES_QUEUE_H_