Android: Make audioInputStateChanged watcher work so it can restart input audio if it stops without a reason. Implement a mechanism that counts last reads in an interval and restart input audio in case of low reads -in these cases (happens particularly on Huawei) there is no call to the audioInputStateChanged method- (Android only)

libraries/audio-client/src/AudioClient.cpp

@@ -52,11 +52,21 @@
 
 #include "AudioClient.h"
 
+#if defined(Q_OS_ANDROID)
+const int AudioClient::MIN_BUFFER_FRAMES = 20;
+#else
 const int AudioClient::MIN_BUFFER_FRAMES = 1;
+#endif
+
 const int AudioClient::MAX_BUFFER_FRAMES = 20;
 
 static const int RECEIVED_AUDIO_STREAM_CAPACITY_FRAMES = 100;
 
+#if defined(Q_OS_ANDROID)
+static const int CHECK_INPUT_READS_MSECS = 2000;
+static const int MIN_READS_TO_CONSIDER_INPUT_ALIVE = 100;
+#endif
+
 static const auto DEFAULT_POSITION_GETTER = []{ return Vectors::ZERO; };
 static const auto DEFAULT_ORIENTATION_GETTER = [] { return Quaternions::IDENTITY; };
 
@@ -197,6 +207,9 @@ AudioClient::AudioClient() :
     _audioOutputIODevice(_localInjectorsStream, _receivedAudioStream, this),
     _stats(&_receivedAudioStream),
     _positionGetter(DEFAULT_POSITION_GETTER),
+#if defined(Q_OS_ANDROID)
+    _checkInputTimer(this),
+#endif
     _orientationGetter(DEFAULT_ORIENTATION_GETTER) {
     // avoid putting a lock in the device callback
     assert(_localSamplesAvailable.is_lock_free());
@@ -278,6 +291,9 @@ void AudioClient::cleanupBeforeQuit() {
         return;
     }
 
+#if defined(Q_OS_ANDROID)
+    _shouldRestartInputSetup = false;
+#endif
     stop();
     _checkDevicesTimer->stop();
     _checkPeakValuesTimer->stop();
@@ -622,6 +638,12 @@ void AudioClient::start() {
         qCDebug(audioclient) << "Unable to set up audio output because of a problem with output format.";
         qCDebug(audioclient) << "The closest format available is" << outputDeviceInfo.nearestFormat(_desiredOutputFormat);
     }
+#if defined(Q_OS_ANDROID)
+    connect(&_checkInputTimer, &QTimer::timeout, [this] {
+        checkInputTimeout();
+    });
+    _checkInputTimer.start(CHECK_INPUT_READS_MSECS);
+#endif
 }
 
 void AudioClient::stop() {
@@ -631,6 +653,9 @@ void AudioClient::stop() {
 
     qCDebug(audioclient) << "AudioClient::stop(), requesting switchOutputToAudioDevice() to shut down";
     switchOutputToAudioDevice(QAudioDeviceInfo(), true);
+#if defined(Q_OS_ANDROID)
+    _checkInputTimer.stop();
+#endif
 }
 
 void AudioClient::handleAudioEnvironmentDataPacket(QSharedPointer<ReceivedMessage> message) {
@@ -1090,6 +1115,10 @@ void AudioClient::handleMicAudioInput() {
         return;
     }
 
+#if defined(Q_OS_ANDROID)
+    _inputReadsSinceLastCheck++;
+#endif
+
     // input samples required to produce exactly NETWORK_FRAME_SAMPLES of output
     const int inputSamplesRequired = (_inputToNetworkResampler ?
                                       _inputToNetworkResampler->getMinInput(AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL) :
@@ -1425,6 +1454,10 @@ bool AudioClient::switchInputToAudioDevice(const QAudioDeviceInfo& inputDeviceIn
     // NOTE: device start() uses the Qt internal device list
     Lock lock(_deviceMutex);
 
+#if defined(Q_OS_ANDROID)
+    _shouldRestartInputSetup = false; // avoid a double call to _audioInput->start() from audioInputStateChanged
+#endif
+
     // cleanup any previously initialized device
     if (_audioInput) {
         // The call to stop() causes _inputDevice to be destructed.
@@ -1505,7 +1538,10 @@ bool AudioClient::switchInputToAudioDevice(const QAudioDeviceInfo& inputDeviceIn
 
 #if defined(Q_OS_ANDROID)
                 if (_audioInput) {
-                    connect(_audioInput, SIGNAL(stateChanged(QAudio::State)), this, SLOT(audioInputStateChanged(QAudio::State)));
+                    _shouldRestartInputSetup = true;
+                    connect(_audioInput, &QAudioInput::stateChanged, [this](QAudio::State state) {
+                        audioInputStateChanged(state);
+                    });
                 }
 #endif
                 _inputDevice = _audioInput->start();
@@ -1553,10 +1589,11 @@ void AudioClient::audioInputStateChanged(QAudio::State state) {
             if (!_audioInput) {
                 break;
             }
-                // Stopped on purpose
+            // Stopped on purpose
             if (_shouldRestartInputSetup) {
                 Lock lock(_deviceMutex);
                 _inputDevice = _audioInput->start();
+                qCDebug(audioclient) << "[AUDIO-WA] Restarted _audioInput";
                 lock.unlock();
                 if (_inputDevice) {
                     connect(_inputDevice, SIGNAL(readyRead()), this, SLOT(handleMicAudioInput()));
@@ -1569,6 +1606,18 @@ void AudioClient::audioInputStateChanged(QAudio::State state) {
             break;
     }
 }
+
+void AudioClient::checkInputTimeout() {
+    if (_audioInput && _inputReadsSinceLastCheck < MIN_READS_TO_CONSIDER_INPUT_ALIVE) {
+        qCDebug(audioclient) << "[AUDIO-WA] No input in last second _inputReadsSinceLastCheck" << _inputReadsSinceLastCheck;
+        // this is a weird issue happening at low level in android
+        // it simply stops sending us mic data
+        _audioInput->stop();
+    } else {
+        //qCDebug(audioclient) << "[AUDIO-WA] ok _inputReadsSinceLastCheck " << _inputReadsSinceLastCheck;
+        _inputReadsSinceLastCheck = 0;
+    }
+}
 #endif
 
 void AudioClient::outputNotify() {

libraries/audio-client/src/AudioClient.h

@@ -26,7 +26,6 @@
 #include <QtMultimedia/QAudio>
 #include <QtMultimedia/QAudioFormat>
 #include <QtMultimedia/QAudioInput>
-
 #include <AbstractAudioInterface.h>
 #include <AudioEffectOptions.h>
 #include <AudioStreamStats.h>
@@ -185,6 +184,7 @@ public slots:
     void handleMicAudioInput();
 #if defined(Q_OS_ANDROID)
     void audioInputStateChanged(QAudio::State state);
+    void checkInputTimeout();
 #endif
     void handleDummyAudioInput();
     void handleRecordedAudioInput(const QByteArray& audio);
@@ -276,6 +276,11 @@ private:
     float azimuthForSource(const glm::vec3& relativePosition);
     float gainForSource(float distance, float volume);
 
+#ifdef Q_OS_ANDROID
+    QTimer _checkInputTimer;
+    long _inputReadsSinceLastCheck = 0l;
+#endif
+
     class Gate {
     public:
         Gate(AudioClient* audioClient);