Add UMA stats for silence AudioInputController.

media/audio/audio_input_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/audio_input_controller.h"
 
 #include "base/bind.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
@@ skipping 45 matching lines @@
                                            SyncWriter* sync_writer,
                                            UserInputMonitor* user_input_monitor)
     : creator_task_runner_(base::MessageLoopProxy::current()),
       handler_(handler),
       stream_(NULL),
       data_is_active_(false),
       state_(CLOSED),
       sync_writer_(sync_writer),
       max_volume_(0.0),
       user_input_monitor_(user_input_monitor),
+#if defined(AUDIO_POWER_MONITORING)
+      last_audio_level_was_silence_(false),
+      silence_counter_(0),
+#endif
       prev_key_down_count_(0) {
   DCHECK(creator_task_runner_.get());
 }
 
 AudioInputController::~AudioInputController() {
   DCHECK_EQ(state_, CLOSED);
 }
 
 // static
 scoped_refptr<AudioInputController> AudioInputController::Create(
@@ skipping 120 matching lines @@
 
 #if defined(AUDIO_POWER_MONITORING)
   // Create the audio (power) level meter given the provided audio parameters.
   // An AudioBus is also needed to wrap the raw data buffer from the native
   // layer to match AudioPowerMonitor::Scan().
   // TODO(henrika): Remove use of extra AudioBus. See http://crbug.com/375155.
   audio_level_.reset(new media::AudioPowerMonitor(
       params.sample_rate(),
       TimeDelta::FromMilliseconds(kPowerMeasurementTimeConstantMilliseconds)));
   audio_params_ = params;
+  last_audio_level_was_silence_ = false;
+  silence_counter_ = 0;
 #endif
 
   // TODO(miu): See TODO at top of file.  Until that's resolved, assume all
   // platform audio input requires the |no_data_timer_| be used to auto-detect
   // errors.  In reality, probably only Windows needs to be treated as
   // unreliable here.
   DoCreateForStream(audio_manager->MakeAudioInputStream(params, device_id),
                     true);
 }
 
@@ skipping 84 matching lines @@
 
   DoStopCloseAndClearStream();
   SetDataIsActive(false);
 
   if (SharedMemoryAndSyncSocketMode())
     sync_writer_->Close();
 
   if (user_input_monitor_)
     user_input_monitor_->DisableKeyPressMonitoring();
 
+#if defined(AUDIO_POWER_MONITORING)
+  // Send UMA stats if we have enabled power monitoring.
+  if (audio_level_) {
+    UMA_HISTOGRAM_COUNTS_10000("Media.AudioInputControllerSilenceCount",
+                               silence_counter_);
+  }
+#endif
+
   state_ = CLOSED;
 }
 
 void AudioInputController::DoReportError() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   if (handler_)
     handler_->OnError(this, STREAM_ERROR);
 }
 
 void AudioInputController::DoSetVolume(double volume) {
@@ skipping 147 matching lines @@
 
 void AudioInputController::DoLogAudioLevel(float level_dbfs) {
 #if defined(AUDIO_POWER_MONITORING)
   DCHECK(task_runner_->BelongsToCurrentThread());
   if (!handler_)
     return;
 
   std::string log_string = base::StringPrintf(
       "AIC::OnData: average audio level=%.2f dBFS", level_dbfs);
   static const float kSilenceThresholdDBFS = -72.24719896f;
-  if (level_dbfs < kSilenceThresholdDBFS)
+  if (level_dbfs < kSilenceThresholdDBFS) {
     log_string += " <=> no audio input!";
+    if (!last_audio_level_was_silence_)
+      ++silence_counter_;
+    last_audio_level_was_silence_ = true;
+  } else {
+    last_audio_level_was_silence_ = false;
+  }
 
   handler_->OnLog(this, log_string);
 #endif
 }
 
 void AudioInputController::OnError(AudioInputStream* stream) {
   // Handle error on the audio-manager thread.
   task_runner_->PostTask(FROM_HERE, base::Bind(
       &AudioInputController::DoReportError, this));
 }
@@ skipping 14 matching lines @@
 
 void AudioInputController::SetDataIsActive(bool enabled) {
   base::subtle::Release_Store(&data_is_active_, enabled);
 }
 
 bool AudioInputController::GetDataIsActive() {
   return (base::subtle::Acquire_Load(&data_is_active_) != false);
 }
 
 }  // namespace media