Blackberry: Fix resolution selection for video recording

Fix the selection of the video viewfinder resolution depending
on the features provided by the camera. If the viewfinder is responsible
for encoding the video frames, the resolution of the viewfinder
and the video output must match. Otherwise only the ratio must match
and we can use a lower resolution for the viewfinder to improve
the performance of the NV12->RGB frame conversion.

Change-Id: I66ace84841a69be84f83bf9c5240cd23d96fbb76
Reviewed-by: Bernd Weimer <bweimer@rim.com>
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>

src/plugins/blackberry/camera/bbcameramediarecordercontrol.cpp

@@ -127,7 +127,7 @@ qreal BbCameraMediaRecorderControl::volume() const
 
 void BbCameraMediaRecorderControl::applySettings()
 {
-    m_session->applySettings();
+    m_session->applyVideoSettings();
 }
 
 void BbCameraMediaRecorderControl::setState(QMediaRecorder::State state)

src/plugins/blackberry/camera/bbcamerasession.cpp

@@ -113,6 +113,7 @@ BbCameraSession::BbCameraSession(QObject *parent)
     , m_state(QCamera::UnloadedState)
     , m_captureMode(QCamera::CaptureStillImage)
     , m_device("bb:RearCamera")
+    , m_previewIsVideo(true)
     , m_surface(0)
     , m_captureImageDriveMode(QCameraImageCapture::SingleImageCapture)
     , m_lastImageCaptureId(0)
@@ -591,11 +592,51 @@ qint64 BbCameraSession::duration() const
     return (m_videoRecordingDuration.isValid() ? m_videoRecordingDuration.elapsed() : 0);
 }
 
-void BbCameraSession::applySettings()
+void BbCameraSession::applyVideoSettings()
 {
     if (m_handle == CAMERA_HANDLE_INVALID)
         return;
 
+    // apply viewfinder configuration
+    const QList<QSize> videoOutputResolutions = supportedResolutions(QCamera::CaptureVideo);
+
+    if (!m_videoEncoderSettings.resolution().isValid() || !videoOutputResolutions.contains(m_videoEncoderSettings.resolution()))
+        m_videoEncoderSettings.setResolution(videoOutputResolutions.first());
+
+    QSize viewfinderResolution;
+
+    if (m_previewIsVideo) {
+        // The viewfinder is responsible for encoding the video frames, so the resolutions must match.
+        viewfinderResolution = m_videoEncoderSettings.resolution();
+    } else {
+        // The frames are encoded separately from the viewfinder, so only the aspect ratio must match.
+        const QSize videoResolution = m_videoEncoderSettings.resolution();
+        const qreal aspectRatio = static_cast<qreal>(videoResolution.width())/static_cast<qreal>(videoResolution.height());
+
+        QList<QSize> sizes = supportedViewfinderResolutions(QCamera::CaptureVideo);
+        std::reverse(sizes.begin(), sizes.end()); // use smallest possible resolution
+        foreach (const QSize &size, sizes) {
+            // search for viewfinder resolution with the same aspect ratio
+            if (qFuzzyCompare(aspectRatio, (static_cast<qreal>(size.width())/static_cast<qreal>(size.height())))) {
+                viewfinderResolution = size;
+                break;
+            }
+        }
+    }
+
+    Q_ASSERT(viewfinderResolution.isValid());
+
+    camera_error_t result = CAMERA_EOK;
+    result = camera_set_videovf_property(m_handle,
+                                         CAMERA_IMGPROP_WIDTH, viewfinderResolution.width(),
+                                         CAMERA_IMGPROP_HEIGHT, viewfinderResolution.height(),
+                                         CAMERA_IMGPROP_ROTATION, 360 - m_nativeCameraOrientation);
+
+    if (result != CAMERA_EOK) {
+        qWarning() << "Unable to apply video viewfinder settings:" << result;
+        return;
+    }
+
     QString videoCodec = m_videoEncoderSettings.codec();
     if (videoCodec.isEmpty())
         videoCodec = QLatin1String("h264");
@@ -608,14 +649,8 @@ void BbCameraSession::applySettings()
     else if (videoCodec == QLatin1String("h264"))
         cameraVideoCodec = CAMERA_VIDEOCODEC_H264;
 
-    QSize resolution = m_videoEncoderSettings.resolution();
+    const QSize resolution = m_videoEncoderSettings.resolution();
-    if (!resolution.isValid()) {
-        const QList<QSize> resolutions = supportedResolutions(QCamera::CaptureVideo);
-        if (!resolutions.isEmpty())
-            resolution = resolutions.first();
-    }
 
-    //TODO: how to retrieve the supported video framerates from BB10 API?
     qreal frameRate = m_videoEncoderSettings.frameRate();
     if (frameRate == 0) {
         const QList<qreal> frameRates = supportedFrameRates(QVideoEncoderSettings(), 0);
@@ -635,11 +670,11 @@ void BbCameraSession::applySettings()
     else if (audioCodec == QLatin1String("raw"))
         cameraAudioCodec = CAMERA_AUDIOCODEC_RAW;
 
-    const camera_error_t result = camera_set_video_property(m_handle,
+    result = camera_set_video_property(m_handle,
-                                                            CAMERA_IMGPROP_WIDTH, resolution.width(),
+                                       CAMERA_IMGPROP_WIDTH, resolution.width(),
-                                                            CAMERA_IMGPROP_HEIGHT, resolution.height(),
+                                       CAMERA_IMGPROP_HEIGHT, resolution.height(),
-                                                            CAMERA_IMGPROP_VIDEOCODEC, cameraVideoCodec,
+                                       CAMERA_IMGPROP_VIDEOCODEC, cameraVideoCodec,
-                                                            CAMERA_IMGPROP_AUDIOCODEC, cameraAudioCodec);
+                                       CAMERA_IMGPROP_AUDIOCODEC, cameraAudioCodec);
 
     if (result != CAMERA_EOK) {
         qWarning() << "Unable to apply video settings:" << result;
@@ -668,7 +703,10 @@ QList<qreal> BbCameraSession::supportedFrameRates(const QVideoEncoderSettings &s
     double rates[20];
     bool maxmin = false;
 
-    //TODO: actually we want to retrieve the framerates of the video here, not the viewfinder
+    /**
+     * Since in current version of the BB10 platform the video viewfinder encodes the video frames, we use
+     * the values as returned by camera_get_video_vf_framerates().
+     */
     const camera_error_t result = camera_get_video_vf_framerates(m_handle, 20, &supported, rates, &maxmin);
     if (result != CAMERA_EOK) {
         qWarning() << "Unable to retrieve supported viewfinder framerates:" << result;
@@ -977,6 +1015,8 @@ bool BbCameraSession::openCamera()
         return false;
     }
 
+    m_previewIsVideo = camera_has_feature(m_handle, CAMERA_FEATURE_PREVIEWISVIDEO);
+
     m_status = QCamera::LoadedStatus;
     emit statusChanged(m_status);
 
@@ -1192,39 +1232,7 @@ void BbCameraSession::applyConfiguration()
         }
 
     } else if (m_captureMode & QCamera::CaptureVideo) {
-        const QList<QSize> videoOutputResolutions = supportedResolutions(QCamera::CaptureVideo);
+        applyVideoSettings();
-
-        if (!m_videoEncoderSettings.resolution().isValid() || !videoOutputResolutions.contains(m_videoEncoderSettings.resolution()))
-            m_videoEncoderSettings.setResolution(videoOutputResolutions.first());
-
-        const QSize videoResolution = m_videoEncoderSettings.resolution();
-        const qreal aspectRatio = static_cast<qreal>(videoResolution.width())/static_cast<qreal>(videoResolution.height());
-
-        // apply viewfinder configuration
-        QSize viewfinderResolution;
-        QList<QSize> sizes = supportedViewfinderResolutions(QCamera::CaptureVideo);
-        std::reverse(sizes.begin(), sizes.end()); // use smallest possible resolution
-        foreach (const QSize &size, sizes) {
-            // search for viewfinder resolution with the same aspect ratio
-            if (qFuzzyCompare(aspectRatio, (static_cast<qreal>(size.width())/static_cast<qreal>(size.height())))) {
-                viewfinderResolution = size;
-                break;
-            }
-        }
-
-        Q_ASSERT(viewfinderResolution.isValid());
-
-        const camera_error_t result = camera_set_videovf_property(m_handle,
-                                                                  CAMERA_IMGPROP_WIDTH, viewfinderResolution.width(),
-                                                                  CAMERA_IMGPROP_HEIGHT, viewfinderResolution.height(),
-                                                                  CAMERA_IMGPROP_ROTATION, 360 - m_nativeCameraOrientation);
-
-        if (result != CAMERA_EOK) {
-            qWarning() << "Unable to apply video viewfinder settings:" << result;
-            return;
-        }
-
-        applySettings();
     }
 }
 

src/plugins/blackberry/camera/bbcamerasession.h

@@ -125,7 +125,7 @@ public:
     void setVideoState(QMediaRecorder::State state);
     QMediaRecorder::Status videoStatus() const;
     qint64 duration() const;
-    void applySettings();
+    void applyVideoSettings();
 
     // video encoder settings control
     QList<QSize> supportedResolutions(const QVideoEncoderSettings &settings, bool *continuous) const;
@@ -201,6 +201,7 @@ private:
     QCamera::CaptureModes m_captureMode;
 
     QByteArray m_device;
+    bool m_previewIsVideo;
 
     QPointer<QAbstractVideoSurface> m_surface;
     QMutex m_surfaceMutex;