Tune QP thresholds for HW H.264 encoder.

webrtc/api/java/jni/androidmediaencoder_jni.cc

 /*
  *  Copyright 2015 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 369 matching lines @@
       // (internal) range: [0, 127]. And we cannot change QP_max in HW, so it is
       // always = 127. Note that in SW, QP is that of the user-level range [0,
       // 63].
       const int kLowQpThreshold = 32;
       const int kBadQpThreshold = 92;
       quality_scaler_.Init(kLowQpThreshold, kBadQpThreshold, false,
           codec_settings->startBitrate,
           codec_settings->width, codec_settings->height);
     } else if (codecType_ == kVideoCodecH264) {
       // H264 QP is in the range [0, 51].
-      const int kLowQpThreshold = 17;
-      const int kBadQpThreshold = 40;
+      const int kLowQpThreshold = 21;
+      const int kBadQpThreshold = 36;
       quality_scaler_.Init(kLowQpThreshold, kBadQpThreshold, false,
           codec_settings->startBitrate,
           codec_settings->width, codec_settings->height);
     } else {
       // When adding codec support to additional hardware codecs, also configure
       // their QP thresholds for scaling.
       RTC_NOTREACHED() << "Unsupported codec without configured QP thresholds.";
       scale_ = false;
     }
     quality_scaler_.SetMinResolution(kMinWidth, kMinHeight);
@@ skipping 858 matching lines @@
 }
 
 void MediaCodecVideoEncoderFactory::DestroyVideoEncoder(
     webrtc::VideoEncoder* encoder) {
   ALOGD << "Destroy video encoder.";
   delete encoder;
 }
 
 }  // namespace webrtc_jni