Implement qpSum stat for video send ssrc stats.

webrtc/video/send_statistics_proxy.cc

 /*
  *  Copyright (c) 2013 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 477 matching lines @@
   }
   if (encoded_image.adapt_reason_.bw_resolutions_disabled != -1) {
     bool bw_limited = encoded_image.adapt_reason_.bw_resolutions_disabled > 0;
     uma_container_->bw_limited_frame_counter_.Add(bw_limited);
     if (bw_limited) {
       uma_container_->bw_resolutions_disabled_counter_.Add(
           encoded_image.adapt_reason_.bw_resolutions_disabled);
     }
   }
 
-  if (encoded_image.qp_ != -1 && codec_info) {
-    if (codec_info->codecType == kVideoCodecVP8) {
-      int spatial_idx = (rtp_config_.ssrcs.size() == 1)
-                            ? -1
-                            : static_cast<int>(simulcast_idx);
-      uma_container_->qp_counters_[spatial_idx].vp8.Add(encoded_image.qp_);
-    } else if (codec_info->codecType == kVideoCodecVP9) {
-      int spatial_idx = (codec_info->codecSpecific.VP9.num_spatial_layers == 1)
-                            ? -1
-                            : codec_info->codecSpecific.VP9.spatial_idx;
-      uma_container_->qp_counters_[spatial_idx].vp9.Add(encoded_image.qp_);
+  if (encoded_image.qp_ != -1) {
+    if (!stats_.qp_sum)
+      stats_.qp_sum = rtc::Optional<uint64_t>(0);
+    *stats_.qp_sum += encoded_image.qp_;
+
+    if (codec_info) {
+      if (codec_info->codecType == kVideoCodecVP8) {
+        int spatial_idx = (rtp_config_.ssrcs.size() == 1)
+                              ? -1
+                              : static_cast<int>(simulcast_idx);
+        uma_container_->qp_counters_[spatial_idx].vp8.Add(encoded_image.qp_);
+      } else if (codec_info->codecType == kVideoCodecVP9) {
+        int spatial_idx =
+            (codec_info->codecSpecific.VP9.num_spatial_layers == 1)
+                ? -1
+                : codec_info->codecSpecific.VP9.spatial_idx;
+        uma_container_->qp_counters_[spatial_idx].vp9.Add(encoded_image.qp_);
+      }

[hta-webrtc, 2016/10/27 12:22:35]

I don't understand the code here - it seems that for the non-simulcast casel
(num_spatial_layers == 1), we're indexing qp_counters_ with the index -1. That
seems weird.

Since this is old code, I expect that it has worked. But it looks strange.

[hbos, 2016/10/28 09:25:13]

This confuses me too.

     }
   }
 
   // TODO(asapersson): This is incorrect if simulcast layers are encoded on
   // different threads and there is no guarantee that one frame of all layers
   // are encoded before the next start.
   if (last_sent_frame_timestamp_ > 0 &&
       encoded_image._timeStamp != last_sent_frame_timestamp_) {
     uma_container_->sent_frame_rate_tracker_.AddSamples(1);
     uma_container_->sent_width_counter_.Add(
@@ skipping 126 matching lines @@
   return Fraction(min_required_samples, 1000.0f);
 }
 
 int SendStatisticsProxy::BoolSampleCounter::Fraction(
     int min_required_samples, float multiplier) const {
   if (num_samples < min_required_samples || num_samples == 0)
     return -1;
   return static_cast<int>((sum * multiplier / num_samples) + 0.5f);
 }
 }  // namespace webrtc