Add UMA logging for target audio bitrate

webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.cc

 /*
  *  Copyright (c) 2012 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/modules/audio_coding/main/acm2/audio_coding_module_impl.h"
 
 #include <assert.h>
 #include <stdlib.h>
 #include <vector>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/safe_conversions.h"
 #include "webrtc/engine_configurations.h"
 #include "webrtc/modules/audio_coding/main/interface/audio_coding_module_typedefs.h"
 #include "webrtc/modules/audio_coding/main/acm2/acm_common_defs.h"
 #include "webrtc/modules/audio_coding/main/acm2/acm_resampler.h"
 #include "webrtc/modules/audio_coding/main/acm2/call_statistics.h"
 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/interface/logging.h"
+#include "webrtc/system_wrappers/interface/metrics.h"
 #include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
 #include "webrtc/system_wrappers/interface/trace.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 namespace acm2 {
 
 enum {
   kACMToneEnd = 999
@@ skipping 245 matching lines @@
   //  }
   //
   //  WebRtcACMCodecParams encoder_param;
   //  codec_manager_.current_encoder()->EncoderParams(&encoder_param);
   //
   //  return encoder_param.codec_inst.rate;
 }
 
 void AudioCodingModuleImpl::SetBitRate(int bitrate_bps) {
   CriticalSectionScoped lock(acm_crit_sect_);
-
+  RTC_HISTOGRAM_COUNTS_100("WebRTC.Audio.TargetBitrateInKbps",

[kwiberg-webrtc, 2015/06/11 10:03:13]

Define a constant for this string? You use it in 3 places, and am I correct in
assuming that a misspelling wouldn't trigger a compile-time error?

[hlundin-webrtc, 2015/06/11 10:11:48]

Yes, that might be a good idea. Any suggestion on where to store it?

[kwiberg-webrtc, 2015/06/11 11:01:25]

I think my preferred solution would be for all of WebRTC to define all of these
constants in a central place---metrics.h, say. But something like
acm_common_defs.h might also work.

+                           bitrate_bps / 1000);
   if (codec_manager_.CurrentEncoder()) {
     codec_manager_.CurrentEncoder()->SetTargetBitrate(bitrate_bps);

[kwiberg-webrtc, 2015/06/11 10:03:13]

If this method would just return the bitrate the encoder actually decided to
use, we could log that too. Would that be useful?

[hlundin-webrtc, 2015/06/11 10:11:48]

That could be useful. But it would mean that it must be implemented by all
codecs, not only by those who support changing rates.

[kwiberg-webrtc, 2015/06/11 11:01:25]

Yes---but the implementation would be trivial, so it could be worth it.

But we also set the bitrate when constructing encoders (see the codec_owner.cc
diff in this CL), so maybe a dedicated method just for inquiring about the
target bitrate would be better.

   }
 }
 
 // Set available bandwidth, inform the encoder about the estimated bandwidth
 // received from the remote party.
 // TODO(henrik.lundin): Remove; not used.
 int AudioCodingModuleImpl::SetReceivedEstimatedBandwidth(int bw) {
   CriticalSectionScoped lock(acm_crit_sect_);
   FATAL() << "Dead code?";
   return -1;
@@ skipping 953 matching lines @@
       *channels = 1;
       break;
 #endif
     default:
       FATAL() << "Codec type " << codec_type << " not supported.";
   }
   return true;
 }
 
 }  // namespace webrtc