In screenshare mode, suppress VP8 bitrate overshoot and increase quality

webrtc/modules/video_coding/main/source/generic_encoder.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 37 matching lines @@
     int32_t SetTransportCallback(VCMPacketizationCallback* transport);
     /**
     * Set media Optimization
     */
     void SetMediaOpt (media_optimization::MediaOptimization* mediaOpt);
 
     void SetPayloadType(uint8_t payloadType) { _payloadType = payloadType; };
     void SetInternalSource(bool internalSource) { _internalSource = internalSource; };
 
     void SetRotation(VideoRotation rotation) { _rotation = rotation; }
+    bool GetAndResetFrameProduced();
 
 private:
     VCMPacketizationCallback* _sendCallback;
     media_optimization::MediaOptimization* _mediaOpt;
     uint8_t _payloadType;
     bool _internalSource;
     VideoRotation _rotation;
 
     EncodedImageCallback* post_encode_callback_;
 
+    bool frame_produced_;
+
 #ifdef DEBUG_ENCODER_BIT_STREAM
     FILE* _bitStreamAfterEncoder;
 #endif
 };// end of VCMEncodeFrameCallback class
 
 
 /******************************/
 /* VCMGenericEncoder class    */
 /******************************/
 class VCMGenericEncoder
@@ skipping 64 matching lines @@
 
 private:
     VideoEncoder* const encoder_;
     VideoEncoderRateObserver* const rate_observer_;
     VCMEncodedFrameCallback*  vcm_encoded_frame_callback_;
     uint32_t bit_rate_;
     uint32_t frame_rate_;
     const bool internal_source_;
     mutable rtc::CriticalSection rates_lock_;
     VideoRotation rotation_;
+    bool is_screenshare_;
 }; // end of VCMGenericEncoder class
 
 }  // namespace webrtc
 
 #endif // WEBRTC_MODULES_VIDEO_CODING_GENERIC_ENCODER_H_