trunk/src/modules/video_processing/main/source/video_decimator.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.
 */

/*
 * video_decimator.h
 */
#ifndef VPM_VIDEO_DECIMATOR_H
#define VPM_VIDEO_DECIMATOR_H

#include "typedefs.h"
#include "module_common_types.h"

namespace webrtc {

class VPMVideoDecimator
{
public:
    VPMVideoDecimator();
    ~VPMVideoDecimator();
    
    void Reset();
    
    void EnableTemporalDecimation(bool enable);
    
    WebRtc_Word32 SetMaxFrameRate(WebRtc_UWord32 maxFrameRate);
    WebRtc_Word32 SetTargetFrameRate(WebRtc_UWord32 frameRate);

    bool DropFrame();
    
    void UpdateIncomingFrameRate();

    // Get Decimated Frame Rate/Dimensions
    WebRtc_UWord32 DecimatedFrameRate();

    //Get input frame rate
    WebRtc_UWord32 InputFrameRate();

private:
    void ProcessIncomingFrameRate(WebRtc_Word64 now);

    enum { kFrameCountHistorySize = 90};
    enum { kFrameHistoryWindowMs = 2000};

    // Temporal decimation
    WebRtc_Word32         _overShootModifier;
    WebRtc_UWord32        _dropCount;
    WebRtc_UWord32        _keepCount;
    WebRtc_UWord32        _targetFrameRate;
    float               _incomingFrameRate;
    WebRtc_UWord32        _maxFrameRate;
    WebRtc_Word64         _incomingFrameTimes[kFrameCountHistorySize];
    bool                _enableTemporalDecimation;

};

} //namespace

#endif