AVFoundation: fix microphone permission when using the camera.

The microphone permission was always requested when using the camera,
even when not actually using the microphone, which can only happen when
recording a video. The permission request is triggered by adding an
audio AVCaptureDeviceInput to the AVCaptureSession, which was done when
setting the camera to LoadedState. This is now done when setting the
camera mode to CaptureVideo.

Task-number: QTBUG-45659
Change-Id: I3692797128cfb70ba5ccbc7a36b6955471039e80
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>

1 files changed, 54 insertions, 8 deletions

diff --git a/src/plugins/avfoundation/camera/avfmediarecordercontrol.mm b/src/plugins/avfoundation/camera/avfmediarecordercontrol.mm
index d65d238d9..3e855b46f 100644
--- a/src/plugins/avfoundation/camera/avfmediarecordercontrol.mm
+++ b/src/plugins/avfoundation/camera/avfmediarecordercontrol.mm
@@ -44,6 +44,7 @@
 #include "avfcamerasession.h"
 #include "avfcameraservice.h"
 #include "avfcameracontrol.h"
+#include "avfaudioinputselectorcontrol.h"
 
 #include <QtCore/qurl.h>
 #include <QtCore/qfileinfo.h>
@@ -122,6 +123,7 @@ QT_USE_NAMESPACE
 AVFMediaRecorderControl::AVFMediaRecorderControl(AVFCameraService *service, QObject *parent)
    : QMediaRecorderControl(parent)
    , m_cameraControl(service->cameraControl())
+   , m_audioInputControl(service->audioInputSelectorControl())
    , m_session(service->session())
    , m_connected(false)
    , m_state(QMediaRecorder::StoppedState)
@@ -130,21 +132,29 @@ AVFMediaRecorderControl::AVFMediaRecorderControl(AVFCameraService *service, QObj
    , m_recordingFinished(false)
    , m_muted(false)
    , m_volume(1.0)
+   , m_audioInput(nil)
 {
     m_movieOutput = [[AVCaptureMovieFileOutput alloc] init];
     m_recorderDelagate = [[AVFMediaRecorderDelegate alloc] initWithRecorder:this];
 
     connect(m_cameraControl, SIGNAL(stateChanged(QCamera::State)), SLOT(updateStatus()));
     connect(m_cameraControl, SIGNAL(statusChanged(QCamera::Status)), SLOT(updateStatus()));
-    connect(m_cameraControl, SIGNAL(captureModeChanged(QCamera::CaptureModes)), SLOT(reconnectMovieOutput()));
-
-    reconnectMovieOutput();
+    connect(m_cameraControl, SIGNAL(captureModeChanged(QCamera::CaptureModes)), SLOT(setupSessionForCapture()));
+    connect(m_session, SIGNAL(readyToConfigureConnections()), SLOT(setupSessionForCapture()));
+    connect(m_session, SIGNAL(stateChanged(QCamera::State)), SLOT(setupSessionForCapture()));
 }
 
 AVFMediaRecorderControl::~AVFMediaRecorderControl()
 {
-    if (m_movieOutput)
+    if (m_movieOutput) {
         [m_session->captureSession() removeOutput:m_movieOutput];
+        [m_movieOutput release];
+    }
+
+    if (m_audioInput) {
+        [m_session->captureSession() removeInput:m_audioInput];
+        [m_audioInput release];
+    }
 
     [m_recorderDelagate release];
 }
@@ -315,13 +325,39 @@ void AVFMediaRecorderControl::handleRecordingFailed(const QString &message)
     Q_EMIT error(QMediaRecorder::ResourceError, message);
 }
 
-void AVFMediaRecorderControl::reconnectMovieOutput()
+void AVFMediaRecorderControl::setupSessionForCapture()
 {
     //adding movie output causes high CPU usage even when while recording is not active,
-    //connect it only while video capture mode is enabled
+    //connect it only while video capture mode is enabled.
+    // Similarly, connect the Audio input only in that mode, since it's only necessary
+    // when recording anyway. Adding an Audio input will trigger the microphone permission
+    // request on iOS, but it shoudn't do so until we actually try to record.
     AVCaptureSession *captureSession = m_session->captureSession();
 
-    if (!m_connected && m_cameraControl->captureMode().testFlag(QCamera::CaptureVideo)) {
+    if (!m_connected
+            && m_cameraControl->captureMode().testFlag(QCamera::CaptureVideo)
+            && m_session->state() != QCamera::UnloadedState) {
+
+        // Add audio input
+        // Allow recording even if something wrong happens with the audio input initialization
+        AVCaptureDevice *audioDevice = m_audioInputControl->createCaptureDevice();
+        if (!audioDevice) {
+            qWarning("No audio input device available");
+        } else {
+            NSError *error = nil;
+            m_audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error];
+
+            if (!m_audioInput) {
+                qWarning() << "Failed to create audio device input";
+            } else if (![captureSession canAddInput:m_audioInput]) {
+                qWarning() << "Could not connect the audio input";
+                m_audioInput = 0;
+            } else {
+                [m_audioInput retain];
+                [captureSession addInput:m_audioInput];
+            }
+        }
+
         if ([captureSession canAddOutput:m_movieOutput]) {
             [captureSession addOutput:m_movieOutput];
             m_connected = true;
@@ -329,8 +365,18 @@ void AVFMediaRecorderControl::reconnectMovieOutput()
             Q_EMIT error(QMediaRecorder::ResourceError, tr("Could not connect the video recorder"));
             qWarning() << "Could not connect the video recorder";
         }
-    } else if (m_connected && !m_cameraControl->captureMode().testFlag(QCamera::CaptureVideo)) {
+    } else if (m_connected
+               && (!m_cameraControl->captureMode().testFlag(QCamera::CaptureVideo)
+                   || m_session->state() != QCamera::ActiveState)) {
+
         [captureSession removeOutput:m_movieOutput];
+
+        if (m_audioInput) {
+            [captureSession removeInput:m_audioInput];
+            [m_audioInput release];
+            m_audioInput = nil;
+        }
+
         m_connected = false;
     }