Android: fix QMediaRecorder crashing the camera server on some devices.

Some devices require MediaRecorder.setPreviewDisplay() to always be
called, even though the Android doc says otherwise.

Task-number: QTBUG-37837
Change-Id: I1e9b56f06e7c41bdf684f93b5ec7635f8ae9f379
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/plugins/android/src/mediacapture/qandroidcamerasession.h

@@ -68,6 +68,7 @@ public:
     void setCaptureMode(QCamera::CaptureModes mode);
     bool isCaptureModeSupported(QCamera::CaptureModes mode) const;
 
+    QAndroidVideoOutput *videoOutput() const { return m_videoOutput; }
     void setVideoOutput(QAndroidVideoOutput *output);
     void adjustViewfinderSize(const QSize &captureSize, bool restartPreview = true);
 

src/plugins/android/src/mediacapture/qandroidcapturesession.cpp

@@ -37,6 +37,7 @@
 #include "qandroidcamerasession.h"
 #include "androidmultimediautils.h"
 #include "qandroidmultimediautils.h"
+#include "qandroidvideooutput.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -217,6 +218,20 @@ void QAndroidCaptureSession::start()
     m_usedOutputLocation = QUrl::fromLocalFile(filePath);
     m_mediaRecorder->setOutputFile(filePath);
 
+    // Even though the Android doc explicitly says that calling MediaRecorder.setPreviewDisplay()
+    // is not necessary when the Camera already has a Surface, it doesn't actually work on some
+    // devices. For example on the Samsung Galaxy Tab 2, the camera server dies after prepare()
+    // and start() if MediaRecorder.setPreviewDispaly() is not called.
+    if (m_cameraSession) {
+        // When using a SurfaceTexture, we need to pass a new one to the MediaRecorder, not the same
+        // one that is set on the Camera or it will crash, hence the reset().
+        m_cameraSession->videoOutput()->reset();
+        if (m_cameraSession->videoOutput()->surfaceTexture())
+            m_mediaRecorder->setSurfaceTexture(m_cameraSession->videoOutput()->surfaceTexture());
+        else if (m_cameraSession->videoOutput()->surfaceHolder())
+            m_mediaRecorder->setSurfaceHolder(m_cameraSession->videoOutput()->surfaceHolder());
+    }
+
     if (!m_mediaRecorder->prepare()) {
         emit error(QMediaRecorder::FormatError, QLatin1String("Unable to prepare the media recorder."));
         restartViewfinder();
@@ -412,13 +427,23 @@ void QAndroidCaptureSession::applySettings()
 
 void QAndroidCaptureSession::updateViewfinder()
 {
-    m_cameraSession->camera()->stopPreview();
+    m_cameraSession->camera()->stopPreviewSynchronous();
     m_cameraSession->adjustViewfinderSize(m_videoSettings.resolution(), false);
 }
 
 void QAndroidCaptureSession::restartViewfinder()
 {
     m_cameraSession->camera()->reconnect();
+
+    // This is not necessary on most devices, but it crashes on some if we don't stop the
+    // preview and reset the preview display on the camera when recording is over.
+    m_cameraSession->camera()->stopPreviewSynchronous();
+    m_cameraSession->videoOutput()->reset();
+    if (m_cameraSession->videoOutput()->surfaceTexture())
+        m_cameraSession->camera()->setPreviewTexture(m_cameraSession->videoOutput()->surfaceTexture());
+    else if (m_cameraSession->videoOutput()->surfaceHolder())
+        m_cameraSession->camera()->setPreviewDisplay(m_cameraSession->videoOutput()->surfaceHolder());
+
     m_cameraSession->camera()->startPreview();
     m_cameraSession->setReadyForCapture(true);
 }

src/plugins/android/src/wrappers/jni/androidcamera.cpp

@@ -744,6 +744,12 @@ void AndroidCamera::stopPreview()
     QMetaObject::invokeMethod(d, "stopPreview");
 }
 
+void AndroidCamera::stopPreviewSynchronous()
+{
+    Q_D(AndroidCamera);
+    QMetaObject::invokeMethod(d, "stopPreview", Qt::BlockingQueuedConnection);
+}
+
 AndroidCameraPrivate::AndroidCameraPrivate()
     : QObject(),
       m_parametersMutex(QMutex::Recursive)

src/plugins/android/src/wrappers/jni/androidcamera.h

@@ -155,6 +155,7 @@ public:
 
     void startPreview();
     void stopPreview();
+    void stopPreviewSynchronous();
 
     void takePicture();
 

src/plugins/android/src/wrappers/jni/androidmediarecorder.cpp

@@ -34,6 +34,8 @@
 #include "androidmediarecorder.h"
 
 #include "androidcamera.h"
+#include "androidsurfacetexture.h"
+#include "androidsurfaceview.h"
 #include <QtCore/private/qjni_p.h>
 #include <qmap.h>
 
@@ -339,6 +341,41 @@ void AndroidMediaRecorder::setOutputFile(const QString &path)
     }
 }
 
+void AndroidMediaRecorder::setSurfaceTexture(AndroidSurfaceTexture *texture)
+{
+    QJNIEnvironmentPrivate env;
+    m_mediaRecorder.callMethod<void>("setPreviewDisplay",
+                                     "(Landroid/view/Surface;)V",
+                                     texture->surface());
+    if (env->ExceptionCheck()) {
+#ifdef QT_DEBUG
+        env->ExceptionDescribe();
+#endif
+        env->ExceptionClear();
+    }
+}
+
+void AndroidMediaRecorder::setSurfaceHolder(AndroidSurfaceHolder *holder)
+{
+    QJNIEnvironmentPrivate env;
+    QJNIObjectPrivate surfaceHolder(holder->surfaceHolder());
+    QJNIObjectPrivate surface = surfaceHolder.callObjectMethod("getSurface",
+                                                               "()Landroid/view/Surface;");
+    if (!surface.isValid())
+        return;
+
+    m_mediaRecorder.callMethod<void>("setPreviewDisplay",
+                                     "(Landroid/view/Surface;)V",
+                                     surface.object());
+    if (env->ExceptionCheck()) {
+#ifdef QT_DEBUG
+        env->ExceptionDescribe();
+#endif
+        env->ExceptionClear();
+    }
+}
+
+
 bool AndroidMediaRecorder::initJNI(JNIEnv *env)
 {
     jclass clazz = QJNIEnvironmentPrivate::findClass(QtMediaRecorderListenerClassName,

src/plugins/android/src/wrappers/jni/androidmediarecorder.h

@@ -41,6 +41,8 @@
 QT_BEGIN_NAMESPACE
 
 class AndroidCamera;
+class AndroidSurfaceTexture;
+class AndroidSurfaceHolder;
 
 class AndroidCamcorderProfile
 {
@@ -149,6 +151,9 @@ public:
     void setOutputFormat(OutputFormat format);
     void setOutputFile(const QString &path);
 
+    void setSurfaceTexture(AndroidSurfaceTexture *texture);
+    void setSurfaceHolder(AndroidSurfaceHolder *holder);
+
     static bool initJNI(JNIEnv *env);
 
 Q_SIGNALS:

src/plugins/android/src/wrappers/jni/androidsurfacetexture.cpp

@@ -78,8 +78,8 @@ AndroidSurfaceTexture::AndroidSurfaceTexture(unsigned int texName)
 
 AndroidSurfaceTexture::~AndroidSurfaceTexture()
 {
-    if (QtAndroidPrivate::androidSdkVersion() > 13 && m_surfaceView.isValid())
+    if (QtAndroidPrivate::androidSdkVersion() > 13 && m_surface.isValid())
-        m_surfaceView.callMethod<void>("release");
+        m_surface.callMethod<void>("release");
 
     if (m_surfaceTexture.isValid()) {
         release();
@@ -124,21 +124,23 @@ jobject AndroidSurfaceTexture::surfaceTexture()
     return m_surfaceTexture.object();
 }
 
-jobject AndroidSurfaceTexture::surfaceView()
+jobject AndroidSurfaceTexture::surface()
 {
-    return m_surfaceView.object();
+    if (!m_surface.isValid()) {
+        m_surface = QJNIObjectPrivate("android/view/Surface",
+                                      "(Landroid/graphics/SurfaceTexture;)V",
+                                      m_surfaceTexture.object());
+    }
+
+    return m_surface.object();
 }
 
 jobject AndroidSurfaceTexture::surfaceHolder()
 {
     if (!m_surfaceHolder.isValid()) {
-        m_surfaceView = QJNIObjectPrivate("android/view/Surface",
-                                          "(Landroid/graphics/SurfaceTexture;)V",
-                                          m_surfaceTexture.object());
-
         m_surfaceHolder = QJNIObjectPrivate("org/qtproject/qt5/android/multimedia/QtSurfaceTextureHolder",
                                             "(Landroid/view/Surface;)V",
-                                            m_surfaceView.object());
+                                            surface());
     }
 
     return m_surfaceHolder.object();

src/plugins/android/src/wrappers/jni/androidsurfacetexture.h

@@ -50,7 +50,7 @@ public:
 
     int textureID() const { return m_texID; }
     jobject surfaceTexture();
-    jobject surfaceView();
+    jobject surface();
     jobject surfaceHolder();
     inline bool isValid() const { return m_surfaceTexture.isValid(); }
 
@@ -66,7 +66,7 @@ Q_SIGNALS:
 private:
     int m_texID;
     QJNIObjectPrivate m_surfaceTexture;
-    QJNIObjectPrivate m_surfaceView;
+    QJNIObjectPrivate m_surface;
     QJNIObjectPrivate m_surfaceHolder;
 };