Update VP8 settings to avoid spending bitrate on static areas. PERF NOTE

webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc

 /*
  *  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 646 matching lines @@
 #endif
   vpx_codec_control(&encoders_[0], VP8E_SET_NOISE_SENSITIVITY,
                     codec_.codecSpecific.VP8.denoisingOn ?
                     denoiser_state : kDenoiserOff);
   if (encoders_.size() > 2) {
     vpx_codec_control(&encoders_[1], VP8E_SET_NOISE_SENSITIVITY,
                       codec_.codecSpecific.VP8.denoisingOn ?
                       denoiser_state : kDenoiserOff);
   }
   for (size_t i = 0; i < encoders_.size(); ++i) {
-    vpx_codec_control(&(encoders_[i]), VP8E_SET_STATIC_THRESHOLD, 1);
+    vpx_codec_control(&(encoders_[i]), VP8E_SET_STATIC_THRESHOLD, 300);

[marpan, 2015/09/30 15:45:30]

condition this change only for screen_content_mode for now..

[sprang_webrtc, 2015/10/01 11:17:03]

Done.

     vpx_codec_control(&(encoders_[i]), VP8E_SET_CPUUSED, cpu_speed_[i]);
     vpx_codec_control(&(encoders_[i]), VP8E_SET_TOKEN_PARTITIONS,
                       static_cast<vp8e_token_partitions>(token_partitions_));
     vpx_codec_control(&(encoders_[i]), VP8E_SET_MAX_INTRA_BITRATE_PCT,
                       rc_max_intra_target_);
     // VP8E_SET_SCREEN_CONTENT_MODE 2 = screen content with more aggressive
     // rate control (drop frames on large target bitrate overshoot)
     vpx_codec_control(&(encoders_[i]), VP8E_SET_SCREEN_CONTENT_MODE,
                       codec_.mode == kScreensharing ? 2 : 0);
   }
@@ skipping 718 matching lines @@
     return -1;
   }
   if (vpx_codec_control(copy->decoder_, VP8_SET_REFERENCE, ref_frame_)
       != VPX_CODEC_OK) {
     return -1;
   }
   return 0;
 }
 
 }  // namespace webrtc