Add stats for average QP per frame for VP8 (for received video streams).

talk/app/webrtc/java/jni/androidmediaencoder_jni.cc

 /*
  * libjingle
  * Copyright 2015 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 777 matching lines @@
 
       // Generate a header describing a single fragment.
       webrtc::RTPFragmentationHeader header;
       memset(&header, 0, sizeof(header));
       if (codecType_ == kVideoCodecVP8) {
         header.VerifyAndAllocateFragmentationHeader(1);
         header.fragmentationOffset[0] = 0;
         header.fragmentationLength[0] = image->_length;
         header.fragmentationPlType[0] = 0;
         header.fragmentationTimeDiff[0] = 0;
-        if (scale_)
-          quality_scaler_.ReportQP(webrtc::vp8::GetQP(payload));
+        if (scale_) {
+          int qp;
+          bool found = webrtc::vp8::GetQp(payload, payload_size, &qp);
+          RTC_DCHECK(found);
+          if (found)

[magjed_webrtc, 2015/10/20 13:17:20]

You shouldn't handle DCHECK failures. At least this is the case according to the
Chromium style guide:
https://www.chromium.org/developers/coding-style#TOC-CHECK-DCHECK-and-NOTREAC...

[åsapersson, 2015/10/20 13:52:36]

Ok. Removed check.

+            quality_scaler_.ReportQP(qp);
+        }
       } else if (codecType_ == kVideoCodecH264) {
         if (scale_) {
           h264_bitstream_parser_.ParseBitstream(payload, payload_size);
           int qp;
           if (h264_bitstream_parser_.GetLastSliceQp(&qp))
             quality_scaler_.ReportQP(qp);
         }
         // For H.264 search for start codes.
         int32_t scPositions[MAX_NALUS_PERFRAME + 1] = {};
         int32_t scPositionsLength = 0;
@@ skipping 142 matching lines @@
 }
 
 void MediaCodecVideoEncoderFactory::DestroyVideoEncoder(
     webrtc::VideoEncoder* encoder) {
   ALOGD << "Destroy video encoder.";
   delete encoder;
 }
 
 }  // namespace webrtc_jni