Tune QP threshold for HW codecs.

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 374 matching lines @@
   ALOGD << "InitEncode request: " << init_width << " x " << init_height;
   ALOGD << "Encoder automatic resize " << (scale_ ? "enabled" : "disabled");
 
   if (scale_) {
     if (codecType_ == kVideoCodecVP8) {
       // QP is obtained from VP8-bitstream for HW, so the QP corresponds to the
       // (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 = 29;
-      const int kBadQpThreshold = 100;
+      const int kBadQpThreshold = 90;
       quality_scaler_.Init(kLowQpThreshold, kBadQpThreshold,
                            codec_settings->startBitrate, codec_settings->width,
                            codec_settings->height,
                            codec_settings->maxFramerate);
     } else if (codecType_ == kVideoCodecH264) {
       // H264 QP is in the range [0, 51].
-      const int kLowQpThreshold = 24;
-      const int kBadQpThreshold = 39;
+      const int kLowQpThreshold = 22;
+      const int kBadQpThreshold = 35;
       quality_scaler_.Init(kLowQpThreshold, kBadQpThreshold,
                            codec_settings->startBitrate, codec_settings->width,
                            codec_settings->height,
                            codec_settings->maxFramerate);
     } 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;
     }
@@ skipping 854 matching lines @@
   return supported_codecs_;
 }
 
 void MediaCodecVideoEncoderFactory::DestroyVideoEncoder(
     webrtc::VideoEncoder* encoder) {
   ALOGD << "Destroy video encoder.";
   delete encoder;
 }
 
 }  // namespace webrtc_jni