android-backend: Route audio from input to output device

CaptureSession has a functionality of route audio to an output device by
assigning an AudioOutput object to the audioOutput property. It was
missing in android-backend.

This commit add implementation for streaming audio from chosen input
device to chosen output device.

Fixes: QTBUG-109659
Change-Id: I07dfe2188dd9e98a740ccaa6188daaf8e34ca0df
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
(cherry picked from commit b5e0c68b965bd9e6ea99e1c20994d33194324220)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

5 files changed, 116 insertions, 1 deletions

diff --git a/src/android/jar/src/org/qtproject/qt/android/multimedia/QtAudioDeviceManager.java b/src/android/jar/src/org/qtproject/qt/android/multimedia/QtAudioDeviceManager.java
index 98690bfb5..09c80b84f 100644
--- a/src/android/jar/src/org/qtproject/qt/android/multimedia/QtAudioDeviceManager.java
+++ b/src/android/jar/src/org/qtproject/qt/android/multimedia/QtAudioDeviceManager.java
@@ -13,7 +13,10 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.media.AudioDeviceInfo;
+import android.media.AudioFormat;
 import android.media.AudioManager;
+import android.media.AudioRecord;
+import android.media.AudioTrack;
 import android.media.MediaRecorder;
 import android.util.Log;
 
@@ -22,6 +25,14 @@ public class QtAudioDeviceManager
     private static final String TAG = "QtAudioDeviceManager";
     static private AudioManager m_audioManager = null;
     static private final AudioDevicesReceiver m_audioDevicesReceiver = new AudioDevicesReceiver();
+    static private AudioRecord m_recorder = null;
+    static private AudioTrack m_streamPlayer = null;
+    static private Thread m_streamingThread = null;
+    static private boolean m_isStreaming = false;
+    static private final int m_sampleRate = 8000;
+    static private final int m_channels = AudioFormat.CHANNEL_CONFIGURATION_MONO;
+    static private final int m_audioFormat = AudioFormat.ENCODING_PCM_16BIT;
+    static private final int m_bufferSize = AudioRecord.getMinBufferSize(m_sampleRate, m_channels, m_audioFormat);
 
     public static native void onAudioInputDevicesUpdated();
     public static native void onAudioOutputDevicesUpdated();
@@ -251,4 +262,65 @@ public class QtAudioDeviceManager
         m_audioManager.setSpeakerphoneOn(speakerOn);
 
     }
+
+    private static void streamSound()
+    {
+        byte data[] = new byte[m_bufferSize];
+        while (m_isStreaming) {
+            m_recorder.read(data, 0, m_bufferSize);
+            m_streamPlayer.play();
+            m_streamPlayer.write(data, 0, m_bufferSize);
+            m_streamPlayer.stop();
+        }
+    }
+
+    private static void startSoundStreaming(int inputId, int outputId)
+    {
+        if (m_isStreaming)
+            stopSoundStreaming();
+
+        m_recorder = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, m_sampleRate, m_channels,
+                                           m_audioFormat, m_bufferSize);
+        m_streamPlayer = new AudioTrack(AudioManager.STREAM_MUSIC, m_sampleRate, m_channels,
+                                           m_audioFormat, m_bufferSize, AudioTrack.MODE_STREAM);
+
+        final AudioDeviceInfo[] devices = m_audioManager.getDevices(AudioManager.GET_DEVICES_ALL);
+        for (AudioDeviceInfo deviceInfo : devices) {
+            if (deviceInfo.getId() == outputId) {
+                m_streamPlayer.setPreferredDevice(deviceInfo);
+            } else if (deviceInfo.getId() == inputId) {
+                m_recorder.setPreferredDevice(deviceInfo);
+            }
+        }
+
+        m_recorder.startRecording();
+        m_isStreaming = true;
+
+        m_streamingThread = new Thread(new Runnable() {
+            public void run() {
+                streamSound();
+            }
+        });
+
+        m_streamingThread.start();
+    }
+
+    private static void stopSoundStreaming()
+    {
+        if (!m_isStreaming)
+            return;
+
+        m_isStreaming = false;
+        try {
+            m_streamingThread.join();
+            m_streamingThread = null;
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        m_recorder.stop();
+        m_recorder.release();
+        m_streamPlayer.release();
+        m_streamPlayer = null;
+        m_recorder = null;
+    }
 }
diff --git a/src/plugins/multimedia/android/mediacapture/qandroidcapturesession.cpp b/src/plugins/multimedia/android/mediacapture/qandroidcapturesession.cpp
index afee45e2f..920249135 100644
--- a/src/plugins/multimedia/android/mediacapture/qandroidcapturesession.cpp
+++ b/src/plugins/multimedia/android/mediacapture/qandroidcapturesession.cpp
@@ -6,6 +6,7 @@
 #include "androidcamera_p.h"
 #include "qandroidcamerasession_p.h"
 #include "qaudioinput.h"
+#include "qaudiooutput.h"
 #include "androidmediaplayer_p.h"
 #include "androidmultimediautils_p.h"
 #include "qandroidmultimediautils_p.h"
@@ -39,6 +40,8 @@ QAndroidCaptureSession::~QAndroidCaptureSession()
 {
     stop();
     m_mediaRecorder = nullptr;
+    if (m_audioInput && m_audioOutput)
+        AndroidMediaPlayer::stopSoundStreaming();
 }
 
 void QAndroidCaptureSession::setCameraSession(QAndroidCameraSession *cameraSession)
@@ -75,8 +78,10 @@ void QAndroidCaptureSession::setAudioInput(QPlatformAudioInput *input)
         m_audioInputChanged = connect(m_audioInput->q, &QAudioInput::deviceChanged, this, [this]() {
             if (m_state == QMediaRecorder::RecordingState)
                 m_mediaRecorder->setAudioInput(m_audioInput->device.id());
+            updateStreamingState();
         });
     }
+    updateStreamingState();
 }
 
 void QAndroidCaptureSession::setAudioOutput(QPlatformAudioOutput *output)
@@ -84,10 +89,30 @@ void QAndroidCaptureSession::setAudioOutput(QPlatformAudioOutput *output)
     if (m_audioOutput == output)
         return;
 
+    if (m_audioOutput)
+        disconnect(m_audioOutputChanged);
+
     m_audioOutput = output;
 
-    if (m_audioOutput)
+    if (m_audioOutput) {
+        m_audioOutputChanged = connect(m_audioOutput->q, &QAudioOutput::deviceChanged, this,
+            [this] () {
+                AndroidMediaPlayer::setAudioOutput(m_audioOutput->device.id());
+                updateStreamingState();
+            });
         AndroidMediaPlayer::setAudioOutput(m_audioOutput->device.id());
+    }
+    updateStreamingState();
+}
+
+void QAndroidCaptureSession::updateStreamingState()
+{
+    if (m_audioInput && m_audioOutput) {
+        AndroidMediaPlayer::startSoundStreaming(m_audioInput->device.id().toInt(),
+                                                m_audioOutput->device.id().toInt());
+    } else {
+        AndroidMediaPlayer::stopSoundStreaming();
+    }
 }
 
 QMediaRecorder::RecorderState QAndroidCaptureSession::state() const
diff --git a/src/plugins/multimedia/android/mediacapture/qandroidcapturesession_p.h b/src/plugins/multimedia/android/mediacapture/qandroidcapturesession_p.h
index 42feb4c1e..ab91fc3ef 100644
--- a/src/plugins/multimedia/android/mediacapture/qandroidcapturesession_p.h
+++ b/src/plugins/multimedia/android/mediacapture/qandroidcapturesession_p.h
@@ -117,6 +117,7 @@ private:
     CaptureProfile getProfile(int id);
 
     void restartViewfinder();
+    void updateStreamingState();
 
     QAndroidMediaEncoder *m_mediaEncoder = nullptr;
     std::shared_ptr<AndroidMediaRecorder> m_mediaRecorder;
@@ -144,6 +145,7 @@ private:
     QList<qreal> m_supportedFramerates;
 
     QMetaObject::Connection m_audioInputChanged;
+    QMetaObject::Connection m_audioOutputChanged;
     QMetaObject::Connection m_connOpenCamera;
     QMetaObject::Connection m_connActiveChangedCamera;
 
diff --git a/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer.cpp b/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer.cpp
index 51e0aa46f..67907dcd7 100644
--- a/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer.cpp
+++ b/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer.cpp
@@ -252,6 +252,20 @@ void AndroidMediaPlayer::unblockAudio()
     mAudioBlocked = false;
 }
 
+void AndroidMediaPlayer::startSoundStreaming(const int inputId, const int outputId)
+{
+    QJniObject::callStaticMethod<void>("org/qtproject/qt/android/multimedia/QtAudioDeviceManager",
+                                       "startSoundStreaming",
+                                       inputId,
+                                       outputId);
+}
+
+void AndroidMediaPlayer::stopSoundStreaming()
+{
+    QJniObject::callStaticMethod<void>(
+        "org/qtproject/qt/android/multimedia/QtAudioDeviceManager", "stopSoundStreaming");
+}
+
 bool AndroidMediaPlayer::setPlaybackRate(qreal rate)
 {
     if (QNativeInterface::QAndroidApplication::sdkVersion() < 23) {
diff --git a/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer_p.h b/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer_p.h
index 46cd73688..66095b114 100644
--- a/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer_p.h
+++ b/src/plugins/multimedia/android/wrappers/jni/androidmediaplayer_p.h
@@ -100,6 +100,8 @@ public:
     void setDataSource(const QNetworkRequest &request);
     void prepareAsync();
     void setVolume(int volume);
+    static void startSoundStreaming(const int inputId, const int outputId);
+    static void stopSoundStreaming();
     bool setPlaybackRate(qreal rate);
     void setDisplay(AndroidSurfaceTexture *surfaceTexture);
     static bool setAudioOutput(const QByteArray &deviceId);