Qt6.5 QCamera setting the cameraFormat was NV12 why output was UYVY?

[zruibin]

I was setting the format(Format_NV12) on QCamera by setCameraFormat, but the output format was uyvy(Format_UYVY) from QVideoSink on apple m1 machine finally, why?

It was NORMAL on apple intel machine(output was nv12).

That's very strangely!

Qt Version: 6.5

And rollback to 6.4.3，no such problem!!!

code:

QCameraDevice cameraDevice;
const QList<QCameraDevice> availableCameras = QMediaDevices::videoInputs();
for (const QCameraDevice &availableCamera : availableCameras) {
    if (availableCamera == QMediaDevices::defaultVideoInput())
        cameraDevice = availableCamera;
}
camera_.reset(new QCamera(cameraDevice));
if (camera_->cameraFormat().isNull()) {
    auto formats = cameraDevice.videoFormats();
    if (!formats.isEmpty()) {
        QCameraFormat bestFormat;
        for (const auto &fmt : formats) {
            if (fmt.pixelFormat() == QVideoFrameFormat::Format_NV12
                && fmt.resolution().width() > fmt.resolution().height()
                && bestFormat.resolution().width() < fmt.resolution().width()
                && bestFormat.resolution().height() < fmt.resolution().height()) {
                bestFormat = fmt;
            }
        }

        camera_->setCameraFormat(bestFormat);
    }
}

captureSession_.setCamera(camera_.data());
captureSession_.setVideoSink(&videoSink_);

connect(&videoSink_, &QVideoSink::videoFrameChanged, this, &VideoCaputer::OnFrameChanged);

...

void VideoCaputer::OnFrameChanged(const QVideoFrame &frame) {
    // why? just on apple m1
   if (frame.pixelFormat() == QVideoFrameFormat::Format_UYVY) {
       qDebug()<< "pixelFormat error";
       return;
   }

}

[Bonnie]

@zruibin Did you check whether bestFormat is Format_NV12 or not?
I just think maybe cameraDevice.videoFormats() doesn't support Format_NV12 on that machine/camera?

[zruibin]

@Bonnie I was confirm check the bestFormat was set Format_NV12 by qDebug output.