Add stats for used video codec type for a sent video stream:

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.
  */
 
 #include "webrtc/video/send_statistics_proxy.h"
 
 #include <algorithm>
 #include <map>
 
 #include "webrtc/base/checks.h"
 
 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/interface/logging.h"
 #include "webrtc/system_wrappers/interface/metrics.h"
 
 namespace webrtc {
+namespace {
+// Used by histograms. Values of entries should not be changed.
+enum HistogramCodecType {
+  kVideoVp8 = 0,

[pbos-webrtc, 2015/10/26 13:19:03]

I'd prefer unknown to be zero, and then set explicit values for VP9 and H264 as
well, so that we don't risk that they change.

[åsapersson, 2015/10/26 14:19:53]

Done.

+  kVideoVp9,
+  kVideoH264,
+  kVideoUnknown = 19,
+  kVideoMax = 20,

[pbos-webrtc, 2015/10/26 13:19:03]

I think you can pick something larger if this isn't supposed to change, like 64.
It shouldn't matter either way.

[åsapersson, 2015/10/26 14:19:53]

Done.

+};
+
+HistogramCodecType PayloadNameToHistogramCodecType(
+    const std::string& payload_name) {
+  if (payload_name == "VP8") {
+    return kVideoVp8;
+  } else if (payload_name == "VP9") {
+    return kVideoVp9;
+  } else if (payload_name == "H264") {
+    return kVideoH264;
+  } else {
+    return kVideoUnknown;
+  }
+}
+
+void UpdateCodecTypeHistogram(const std::string& payload_name) {
+  RTC_HISTOGRAM_ENUMERATION("WebRTC.Video.Encoder.CodecType",
+      PayloadNameToHistogramCodecType(payload_name), kVideoMax);
+}
+}  // namespace
+
 
 const int SendStatisticsProxy::kStatsTimeoutMs = 5000;
 
 SendStatisticsProxy::SendStatisticsProxy(Clock* clock,
                                          const VideoSendStream::Config& config)
     : clock_(clock),
       config_(config),
       input_frame_rate_tracker_(100u, 10u),
       sent_frame_rate_tracker_(100u, 10u),
       last_sent_frame_timestamp_(0),
       max_sent_width_per_timestamp_(0),
       max_sent_height_per_timestamp_(0) {
+  UpdateCodecTypeHistogram(config_.encoder_settings.payload_name);
 }
 
 SendStatisticsProxy::~SendStatisticsProxy() {
   UpdateHistograms();
 }
 
 void SendStatisticsProxy::UpdateHistograms() {
   int input_fps =
       static_cast<int>(input_frame_rate_tracker_.ComputeTotalRate());
   if (input_fps > 0)
@@ skipping 292 matching lines @@
 }
 
 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