What is the proper solution to process the frame of camera on android?

tham

Qt5.9.1
os : win 10 64bits
Android sdk : 19
Phone : GTS-6310
android version : 4.1.2

I am trying to process camera frame of android by QCamera and QAbstractVideoSurface. What I try

class camera_frame_grabber : public QAbstractVideoSurface
{
    Q_OBJECT
public:
    camera_frame_grabber(QObject *parent = nullptr);

    QList<QVideoFrame::PixelFormat>
    supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType) const override;

    bool present(const QVideoFrame &frame) override;

signals:
    void frame_available(QImage frame);
};

camera_frame_grabber::camera_frame_grabber(QObject *parent) :
    QAbstractVideoSurface(parent)
{

}

QList<QVideoFrame::PixelFormat>
camera_frame_grabber::supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType) const
{
    Q_UNUSED(handleType);
    return QList<QVideoFrame::PixelFormat>()
            << QVideoFrame::Format_ARGB32
            << QVideoFrame::Format_ARGB32_Premultiplied
            << QVideoFrame::Format_RGB32
            << QVideoFrame::Format_RGB24
            << QVideoFrame::Format_RGB565
            << QVideoFrame::Format_RGB555
            << QVideoFrame::Format_ARGB8565_Premultiplied
            << QVideoFrame::Format_BGRA32
            << QVideoFrame::Format_BGRA32_Premultiplied
            << QVideoFrame::Format_BGR32
            << QVideoFrame::Format_BGR24
            << QVideoFrame::Format_BGR565
            << QVideoFrame::Format_BGR555
            << QVideoFrame::Format_BGRA5658_Premultiplied
            << QVideoFrame::Format_AYUV444
            << QVideoFrame::Format_AYUV444_Premultiplied
            << QVideoFrame::Format_YUV444
            << QVideoFrame::Format_YUV420P
            << QVideoFrame::Format_YV12
            << QVideoFrame::Format_UYVY
            << QVideoFrame::Format_YUYV
            << QVideoFrame::Format_NV12
            << QVideoFrame::Format_NV21
            << QVideoFrame::Format_IMC1
            << QVideoFrame::Format_IMC2
            << QVideoFrame::Format_IMC3
            << QVideoFrame::Format_IMC4
            << QVideoFrame::Format_Y8
            << QVideoFrame::Format_Y16
            << QVideoFrame::Format_Jpeg
            << QVideoFrame::Format_CameraRaw
            << QVideoFrame::Format_AdobeDng;
}

bool camera_frame_grabber::present(const QVideoFrame &frame)
{
    if(frame.isValid()) {        
        QVideoFrame clone_frame(frame);
        //if I do not call map, the app wouldn't crash
        clone_frame.map(QAbstractVideoBuffer::ReadOnly);
        clone_frame.unmap();
    }
    return false;
}

I use the frame buffer as following

camera_frame_grabber frame_grabber;
QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
for(QCameraInfo const &cameraInfo : cameras) {    
    cam_.reset(new QCamera(cameraInfo));            
    cam_->setViewfinder(&frame_grabber_);                        
    pimpl_->cam_->start();
    break;
}

Always crash on android, but works perfect on windows. I guess this is another bug of android

Link of complete codes

tham

I forgot the error message, put at pastebin

mvuori

I think Android may get confused with what formats it can handle. I'd try reducing your list of formats in supportedPixelFormats() to just Format_NV21

tham

@mvuori I change it to Format_NV21, still crash as before, extracting a frame from camera is not an trivial job

tham

I give every solutions a shot, none of them work.

Qt QML Camera to C++ QImage on Android
https://stackoverflow.com/questions/28041741/qt-qml-camera-to-c-qimage-on-android
[Use of QAbstractVideoSurface [closed]]https://stackoverflow.com/questions/26229633/use-of-qabstractvideosurface