Detect AudioInputStream muting and propagate to MediaStreamAudioSource.

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 <inttypes.h>
 
 #include <algorithm>
 #include <limits>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "media/base/user_input_monitor.h"
 
 namespace media {
 namespace {
 
 const int kMaxInputChannels = 3;
+constexpr int kCheckMutedStateIntervalSeconds = 1;
 
 #if defined(AUDIO_POWER_MONITORING)
 // Time in seconds between two successive measurements of audio power levels.
 const int kPowerMonitorLogIntervalSeconds = 15;
 
 // A warning will be logged when the microphone audio volume is below this
 // threshold.
 const int kLowLevelMicrophoneLevelPercent = 10;
 
 // Logs if the user has enabled the microphone mute or not. This is normally
@@ skipping 151 matching lines @@
 #if BUILDFLAG(ENABLE_WEBRTC)
       debug_recording_helper_(params, task_runner_, base::OnceClosure()),
 #endif
       weak_ptr_factory_(this) {
   DCHECK(creator_task_runner_.get());
   DCHECK(handler_);
   DCHECK(sync_writer_);
 }
 
 AudioInputController::~AudioInputController() {
   DCHECK(!audio_callback_);

[Guido Urdaneta, 2017/06/02 14:13:21]

DCHECK that the timer has no value?

[ossu-chromium, 2017/06/02 15:32:45]

Done.

   DCHECK(!stream_);
 }
 
 // static
 scoped_refptr<AudioInputController> AudioInputController::Create(
     AudioManager* audio_manager,
     EventHandler* event_handler,
     SyncWriter* sync_writer,
     UserInputMonitor* user_input_monitor,
     const AudioParameters& params,
@@ skipping 135 matching lines @@
   // functionality to modify the input volume slider. One such example is
   // Windows XP.
   power_measurement_is_enabled_ &= agc_is_supported;
 #else
   stream_to_control->SetAutomaticGainControl(enable_agc);
 #endif
 
   // Finally, keep the stream pointer around, update the state and notify.
   stream_ = stream_to_control;
   handler_->OnCreated(this);
+
+  // Check the current muted state and create a new repeating timer to keep that
+  // updated.
+  CheckMutedState();
+  check_muted_state_timer_.emplace();
+  check_muted_state_timer_->Start(
+      FROM_HERE, base::TimeDelta::FromSeconds(kCheckMutedStateIntervalSeconds),
+      this, &AudioInputController::CheckMutedState);
+  DCHECK(check_muted_state_timer_->IsRunning());
 }
 
 void AudioInputController::DoRecord() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioInputController.RecordTime");
 
   if (!stream_ || audio_callback_)
     return;
 
   handler_->OnLog(this, "AIC::DoRecord");
 
   if (user_input_monitor_) {
     user_input_monitor_->EnableKeyPressMonitoring();
     prev_key_down_count_ = user_input_monitor_->GetKeyPressCount();
   }
 
   stream_create_time_ = base::TimeTicks::Now();
 
   audio_callback_.reset(new AudioCallback(this));
   stream_->Start(audio_callback_.get());
 }
 
 void AudioInputController::DoClose() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   SCOPED_UMA_HISTOGRAM_TIMER("Media.AudioInputController.CloseTime");
 
   if (!stream_)
     return;
 
+  // Stop and destroy the muted check timer.
+  check_muted_state_timer_.reset();
+
   // Allow calling unconditionally and bail if we don't have a stream to close.
   if (audio_callback_) {
     stream_->Stop();
 
     // Sometimes a stream (and accompanying audio track) is created and
     // immediately closed or discarded. In this case they are registered as
     // 'stopped early' rather than 'never got data'.
     const base::TimeDelta duration =
         base::TimeTicks::Now() - stream_create_time_;
     CaptureStartupResult capture_startup_result =
@@ skipping 250 matching lines @@
   *mic_volume_percent = static_cast<int>(100.0 * volume);
 
   last_audio_level_log_time_ = now;
 
   return true;
 #else
   return false;
 #endif
 }
 
+void AudioInputController::CheckMutedState() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  DCHECK(stream_);
+  const bool new_state = stream_->IsMuted();
+  if (new_state != is_muted_) {
+    is_muted_ = new_state;
+    // Don't log this here, AudioInputRendererHost will log instead.

[Guido Urdaneta, 2017/06/02 14:13:21]

remove obsolete comment

[ossu-chromium, 2017/06/02 15:32:45]

No, I added it so that anyone scouring this code, wondering why this isn't
logged, will know that it is, just not right here. I've rephrased it to try to
make it clearer.

+    handler_->OnMuted(this, is_muted_);
+  }
+}
+
 // static
 AudioInputController::StreamType AudioInputController::ParamsToStreamType(
     const AudioParameters& params) {
   switch (params.format()) {
     case AudioParameters::Format::AUDIO_PCM_LINEAR:
       return AudioInputController::StreamType::HIGH_LATENCY;
     case AudioParameters::Format::AUDIO_PCM_LOW_LATENCY:
       return AudioInputController::StreamType::LOW_LATENCY;
     default:
       // Currently, the remaining supported type is fake. Reconsider if other
       // formats become supported.
       return AudioInputController::StreamType::FAKE;
   }
 }
 
 }  // namespace media