AudioUnit: Don't rely on category switch for mic indicator to turn off

sdk/objc/components/audio/RTCNativeAudioSessionDelegateAdapter.mm

@@ -86,9 +86,4 @@ - (void)audioSession:(RTC_OBJC_TYPE(RTCAudioSession) *)audioSession
   _observer->OnChangedOutputVolume();
 }
 
-- (void)audioSessionDidChangeRecordingEnabled:(RTC_OBJC_TYPE(RTCAudioSession) *)session {
-  // re-trigger audio unit init, by using interrupt ended callback
-  _observer->OnChangedRecordingEnabled();
-}
-
 @end

sdk/objc/native/src/audio/audio_device_ios.h

@@ -147,7 +147,6 @@ class AudioDeviceIOS : public AudioDeviceGeneric,
   void OnValidRouteChange() override;
   void OnCanPlayOrRecordChange(bool can_play_or_record) override;
   void OnChangedOutputVolume() override;
-  void OnChangedRecordingEnabled() override;
 
   // VoiceProcessingAudioUnitObserver methods.
   OSStatus OnDeliverRecordedData(AudioUnitRenderActionFlags* flags,
@@ -175,7 +174,8 @@ class AudioDeviceIOS : public AudioDeviceGeneric,
   void HandleSampleRateChange();
   void HandlePlayoutGlitchDetected();
   void HandleOutputVolumeChange();
-  void HandleAudioSessionRecordingEnabledChange();
+
+  bool RestartAudioUnit(bool enable_input);
 
   // Uses current `playout_parameters_` and `record_parameters_` to inform the
   // audio device buffer (ADB) about our internal audio parameters.
@@ -205,7 +205,7 @@ class AudioDeviceIOS : public AudioDeviceGeneric,
 
   // Activates our audio session, creates and initializes the voice-processing
   // audio unit and verifies that we got the preferred native audio parameters.
-  bool InitPlayOrRecord();
+  bool InitPlayOrRecord(bool enable_input);
 
   // Closes and deletes the voice-processing I/O unit.
   void ShutdownPlayOrRecord();
@@ -269,19 +269,21 @@ class AudioDeviceIOS : public AudioDeviceGeneric,
   // will be changed dynamically to account for this behavior.
   rtc::BufferT<int16_t> record_audio_buffer_;
 
+  // Set to 1 when recording is initialized and 0 otherwise.
+  volatile int recording_is_initialized_;
+
   // Set to 1 when recording is active and 0 otherwise.
   volatile int recording_;
 
+  // Set to 1 when playout is initialized and 0 otherwise.
+  volatile int playout_is_initialized_;
+
   // Set to 1 when playout is active and 0 otherwise.
   volatile int playing_;
 
   // Set to true after successful call to Init(), false otherwise.
   bool initialized_ RTC_GUARDED_BY(thread_checker_);
 
-  // Set to true after successful call to InitRecording() or InitPlayout(),
-  // false otherwise.
-  bool audio_is_initialized_;
-
   // Set to true if audio session is interrupted, false otherwise.
   bool is_interrupted_;
 

sdk/objc/native/src/audio/audio_device_ios.mm

@@ -68,7 +68,6 @@
   kMessageTypeCanPlayOrRecordChange,
   kMessageTypePlayoutGlitchDetected,
   kMessageOutputVolumeChange,
-  kMessageTypeRecordingEnabledChange,
 };
 
 using ios::CheckAndLogError;
@@ -104,10 +103,11 @@ static void LogDeviceInfo() {
     : bypass_voice_processing_(bypass_voice_processing),
       audio_device_buffer_(nullptr),
       audio_unit_(nullptr),
+      recording_is_initialized_(0),
       recording_(0),
+      playout_is_initialized_(0),
       playing_(0),
       initialized_(false),
-      audio_is_initialized_(false),
       is_interrupted_(false),
       has_configured_session_(false),
       num_detected_playout_glitches_(0),
@@ -188,48 +188,62 @@ static void LogDeviceInfo() {
   LOGI() << "InitPlayout";
   RTC_DCHECK_RUN_ON(&thread_checker_);
   RTC_DCHECK(initialized_);
-  RTC_DCHECK(!audio_is_initialized_);
+  RTC_DCHECK(!playout_is_initialized_);
   RTC_DCHECK(!playing_);
-  if (!audio_is_initialized_) {
-    if (!InitPlayOrRecord()) {
+
+  if (!recording_is_initialized_) {
+    // recording not initialized yet, init with no input
+    if (!InitPlayOrRecord(false)) {
       RTC_LOG_F(LS_ERROR) << "InitPlayOrRecord failed for InitPlayout!";
       return -1;
     }
+  } else {
+    // recording is already initialized
+    // RestartAudioUnit(false);
   }
-  audio_is_initialized_ = true;
+
+  rtc::AtomicOps::ReleaseStore(&playout_is_initialized_, 1);
+
   return 0;
 }
 
 bool AudioDeviceIOS::PlayoutIsInitialized() const {
   RTC_DCHECK_RUN_ON(&thread_checker_);
-  return audio_is_initialized_;
+  return playout_is_initialized_;
 }
 
 bool AudioDeviceIOS::RecordingIsInitialized() const {
   RTC_DCHECK_RUN_ON(&thread_checker_);
-  return audio_is_initialized_;
+  return recording_is_initialized_;
 }
 
 int32_t AudioDeviceIOS::InitRecording() {
   LOGI() << "InitRecording";
   RTC_DCHECK_RUN_ON(&thread_checker_);
   RTC_DCHECK(initialized_);
-  RTC_DCHECK(!audio_is_initialized_);
+  RTC_DCHECK(!recording_is_initialized_);
   RTC_DCHECK(!recording_);
-  if (!audio_is_initialized_) {
-    if (!InitPlayOrRecord()) {
+
+  if (!playout_is_initialized_) {
+    // playout not initialized yet, init with input
+    if (!InitPlayOrRecord(true)) {
       RTC_LOG_F(LS_ERROR) << "InitPlayOrRecord failed for InitRecording!";
       return -1;
     }
+  } else {
+    // playout already initialized, restart audio unit with input
+    RestartAudioUnit(true);
   }
-  audio_is_initialized_ = true;
+
+  rtc::AtomicOps::ReleaseStore(&recording_is_initialized_, 1);
+
   return 0;
 }
 
 int32_t AudioDeviceIOS::StartPlayout() {
   LOGI() << "StartPlayout";
   RTC_DCHECK_RUN_ON(&thread_checker_);
-  RTC_DCHECK(audio_is_initialized_);
+  RTC_DCHECK(playout_is_initialized_);
   RTC_DCHECK(!playing_);
   RTC_DCHECK(audio_unit_);
   if (fine_audio_buffer_) {
@@ -254,14 +268,19 @@ static void LogDeviceInfo() {
 int32_t AudioDeviceIOS::StopPlayout() {
   LOGI() << "StopPlayout";
   RTC_DCHECK_RUN_ON(&thread_checker_);
-  if (!audio_is_initialized_ || !playing_) {
+
+  if (!playout_is_initialized_ || !playing_) {
     return 0;
   }
+
   if (!recording_) {
     ShutdownPlayOrRecord();
-    audio_is_initialized_ = false;
+
+    rtc::AtomicOps::ReleaseStore(&recording_is_initialized_, 0);
   }
+
   rtc::AtomicOps::ReleaseStore(&playing_, 0);
+  rtc::AtomicOps::ReleaseStore(&playout_is_initialized_, 0);
 
   // Derive average number of calls to OnGetPlayoutData() between detected
   // audio glitches and add the result to a histogram.
@@ -285,7 +304,7 @@ static void LogDeviceInfo() {
 int32_t AudioDeviceIOS::StartRecording() {
   LOGI() << "StartRecording";
   RTC_DCHECK_RUN_ON(&thread_checker_);
-  RTC_DCHECK(audio_is_initialized_);
+  RTC_DCHECK(recording_is_initialized_);
   RTC_DCHECK(!recording_);
   RTC_DCHECK(audio_unit_);
   if (fine_audio_buffer_) {
@@ -308,14 +327,23 @@ static void LogDeviceInfo() {
 int32_t AudioDeviceIOS::StopRecording() {
   LOGI() << "StopRecording";
   RTC_DCHECK_RUN_ON(&thread_checker_);
-  if (!audio_is_initialized_ || !recording_) {
+
+  if (!recording_is_initialized_ || !recording_) {
     return 0;
   }
+
   if (!playing_) {
     ShutdownPlayOrRecord();
-    audio_is_initialized_ = false;
+
+    rtc::AtomicOps::ReleaseStore(&playout_is_initialized_, 0);
+  } else if (playout_is_initialized_) {
+    // restart audio unit with no input
+    RestartAudioUnit(false);
   }
+
   rtc::AtomicOps::ReleaseStore(&recording_, 0);
+  rtc::AtomicOps::ReleaseStore(&recording_is_initialized_, 0);
+
   return 0;
 }
 
@@ -374,11 +402,6 @@ static void LogDeviceInfo() {
   thread_->Post(RTC_FROM_HERE, this, kMessageOutputVolumeChange);
 }
 
-void AudioDeviceIOS::OnChangedRecordingEnabled() {
-  RTC_DCHECK(thread_);
-  thread_->Post(RTC_FROM_HERE, this, kMessageTypeRecordingEnabledChange);
-}
-
 OSStatus AudioDeviceIOS::OnDeliverRecordedData(AudioUnitRenderActionFlags* flags,
                                                const AudioTimeStamp* time_stamp,
                                                UInt32 bus_number,
@@ -509,9 +532,6 @@ static void LogDeviceInfo() {
     case kMessageOutputVolumeChange:
       HandleOutputVolumeChange();
       break;
-    case kMessageTypeRecordingEnabledChange:
-      HandleAudioSessionRecordingEnabledChange();
-      break;
   }
 }
 
@@ -627,7 +647,7 @@ static void LogDeviceInfo() {
   SetupAudioBuffersForActiveAudioSession();
 
   // Initialize the audio unit again with the new sample rate.
-  if (!audio_unit_->Initialize(playout_parameters_.sample_rate())) {
+  if (!audio_unit_->Initialize(playout_parameters_.sample_rate(), recording_is_initialized_)) {
     RTCLogError(@"Failed to initialize the audio unit with sample rate: %d",
                 playout_parameters_.sample_rate());
     return;
@@ -681,15 +701,15 @@ static void LogDeviceInfo() {
   last_output_volume_change_time_ = rtc::TimeMillis();
 }
 
-void AudioDeviceIOS::HandleAudioSessionRecordingEnabledChange() {
+bool AudioDeviceIOS::RestartAudioUnit(bool enable_input) {
   RTC_DCHECK_RUN_ON(&thread_checker_);
 
-  LOGI() << "HandleAudioSessionRecordingEnabledChange";
+  LOGI() << "RestartAudioUnit";
 
   // If we don't have an audio unit yet, or the audio unit is uninitialized,
   // there is no work to do.
   if (!audio_unit_ || audio_unit_->GetState() < VoiceProcessingAudioUnit::kInitialized) {
-    return;
+    return false;
   }
 
   // The audio unit is already initialized or started.
@@ -700,19 +720,16 @@ static void LogDeviceInfo() {
   // Extra sanity check to ensure that the new sample rate is valid.
   if (session_sample_rate <= 0.0) {
     RTCLogError(@"Sample rate is invalid: %f", session_sample_rate);
-    LOGI() << "Sample rate is invalid " << session_sample_rate;
-    return;
+    return false;
   }
-  // We need to adjust our format and buffer sizes.
-  // The stream format is about to be changed and it requires that we first
-  // stop and uninitialize the audio unit to deallocate its resources.
-  RTCLog(@"Stopping and uninitializing audio unit to adjust buffers.");
+
   bool restart_audio_unit = false;
   if (audio_unit_->GetState() == VoiceProcessingAudioUnit::kStarted) {
     audio_unit_->Stop();
     restart_audio_unit = true;
     PrepareForNewStart();
   }
+
   if (audio_unit_->GetState() == VoiceProcessingAudioUnit::kInitialized) {
     audio_unit_->Uninitialize();
   }
@@ -722,18 +739,19 @@ static void LogDeviceInfo() {
 
   // Initialize the audio unit again with the new sample rate.
   RTC_DCHECK_EQ(playout_parameters_.sample_rate(), session_sample_rate);
-  if (!audio_unit_->Initialize(session_sample_rate)) {
+  if (!audio_unit_->Initialize(session_sample_rate, enable_input)) {
     RTCLogError(@"Failed to initialize the audio unit with sample rate: %f", session_sample_rate);
-    return;
+    return false;
   }
 
   // Restart the audio unit if it was already running.
   if (restart_audio_unit && !audio_unit_->Start()) {
     RTCLogError(@"Failed to start audio unit with sample rate: %f", session_sample_rate);
-    return;
+    return false;
   }
 
   LOGI() << "Successfully enabled audio unit for recording.";
+  return true;
 }
 
 void AudioDeviceIOS::UpdateAudioDeviceBuffer() {
@@ -829,7 +847,7 @@ static void LogDeviceInfo() {
 
   // If we're not initialized we don't need to do anything. Audio unit will
   // be initialized on initialization.
-  if (!audio_is_initialized_) return;
+  if (!playout_is_initialized_ && !recording_is_initialized_) return;
 
   // If we're initialized, we must have an audio unit.
   RTC_DCHECK(audio_unit_);
@@ -866,7 +884,7 @@ static void LogDeviceInfo() {
     RTCLog(@"Initializing audio unit for UpdateAudioUnit");
     ConfigureAudioSession();
     SetupAudioBuffersForActiveAudioSession();
-    if (!audio_unit_->Initialize(playout_parameters_.sample_rate())) {
+    if (!audio_unit_->Initialize(playout_parameters_.sample_rate(), recording_is_initialized_)) {
       RTCLogError(@"Failed to initialize audio unit.");
       return;
     }
@@ -956,7 +974,7 @@ static void LogDeviceInfo() {
   RTCLog(@"Unconfigured audio session.");
 }
 
-bool AudioDeviceIOS::InitPlayOrRecord() {
+bool AudioDeviceIOS::InitPlayOrRecord(bool enable_input) {
   LOGI() << "InitPlayOrRecord";
   RTC_DCHECK_RUN_ON(&thread_checker_);
 
@@ -992,7 +1010,7 @@ static void LogDeviceInfo() {
       return false;
     }
     SetupAudioBuffersForActiveAudioSession();
-    audio_unit_->Initialize(playout_parameters_.sample_rate());
+    audio_unit_->Initialize(playout_parameters_.sample_rate(), enable_input);
   }
 
   // Release the lock.

sdk/objc/native/src/audio/audio_session_observer.h

@@ -32,8 +32,6 @@ class AudioSessionObserver {
 
   virtual void OnChangedOutputVolume() = 0;
 
-  virtual void OnChangedRecordingEnabled() = 0;
-
  protected:
   virtual ~AudioSessionObserver() {}
 };

sdk/objc/native/src/audio/voice_processing_audio_unit.h

@@ -75,7 +75,7 @@ class VoiceProcessingAudioUnit {
   VoiceProcessingAudioUnit::State GetState() const;
 
   // Initializes the underlying audio unit with the given sample rate.
-  bool Initialize(Float64 sample_rate);
+  bool Initialize(Float64 sample_rate, bool enable_input);
 
   // Starts the underlying audio unit.
   OSStatus Start();

sdk/objc/native/src/audio/voice_processing_audio_unit.mm

@@ -180,7 +180,7 @@ static OSStatus GetAGCState(AudioUnit audio_unit, UInt32* enabled) {
   return state_;
 }
 
-bool VoiceProcessingAudioUnit::Initialize(Float64 sample_rate) {
+bool VoiceProcessingAudioUnit::Initialize(Float64 sample_rate, bool enable_input) {
   RTC_DCHECK_GE(state_, kUninitialized);
   RTCLog(@"Initializing audio unit with sample rate: %f", sample_rate);
 
@@ -191,19 +191,11 @@ static OSStatus GetAGCState(AudioUnit audio_unit, UInt32* enabled) {
   LogStreamDescription(format);
 #endif
 
-  // Enable input on the input scope of the input element.
-  // keep it disabled if audio session is configured for playback only
-  AVAudioSession* session = [AVAudioSession sharedInstance];
-  UInt32 enable_input = 0;
-  if ([session.category isEqualToString: AVAudioSessionCategoryPlayAndRecord] ||
-      [session.category isEqualToString: AVAudioSessionCategoryRecord]) {
-    enable_input = 1;
-  }
-  RTCLog(@"Initializing AudioUnit, category=%@, enable_input=%d", session.category, (int) enable_input);
-  // LOGI() << "Initialize" << session.category << ", enable_input=" << enable_input;
+  UInt32 _enable_input = enable_input ? 1 : 0;
+  RTCLog(@"Initializing AudioUnit, _enable_input=%d", (int) _enable_input);
   result = AudioUnitSetProperty(vpio_unit_, kAudioOutputUnitProperty_EnableIO,
-                                kAudioUnitScope_Input, kInputBus, &enable_input,
-                                sizeof(enable_input));
+                                kAudioUnitScope_Input, kInputBus, &_enable_input,
+                                sizeof(_enable_input));
   if (result != noErr) {
     DisposeAudioUnit();
     RTCLogError(@"Failed to enable input on input scope of input element. "