Video Capture in iOS and MacOS

MacOSX and iOS
1

I’m trying to add video streaming to an audio app and have run across some problems with the iOS build. I’m using CameraDevice to capture the video with a listener to queue and encode frames. The project works fine in MacOS, but as soon as I try it on iOS the listener is called exactly once and never again. I also hear the simulated shutter sound on the device, which would suggest that it’s just taking a still picture. The preview component works fine. This is the relevant code:

void VideoCapture::openCameraAsync( int deviceNumber )
{
    SafePointer<VideoCapture> This (this);

    CameraDevice::openDeviceAsync ( deviceNumber,
                               [This] (CameraDevice* device, const String& error) mutable
                               {
                                    This->cameraDeviceOpenResult (device, error);
                               });
}

void VideoCapture::cameraDeviceOpenResult (CameraDevice* device, const String& error)
 {
    // If camera opening worked, create a preview component for it..
   cameraDevice.reset (device);

   if ( cameraDevice.get() != nullptr)
   {
       cameraDevice->addListener( this );
       cameraPreviewComp.reset (cameraDevice->createViewerComponent());
       addAndMakeVisible (cameraPreviewComp.get());
       resized ();
       DBG ( "Camera opened OK" );
   }
   else
   {
       AlertWindow::showMessageBoxAsync (AlertWindow::WarningIcon, "Camera open failed",
                                         "Camera open failed, reason: " + error);
       delete this;
   }
}
void VideoCapture::imageReceived (const Image &image)
{
    if ( image.getWidth() == 0 ) return;
    Image *imageCopy = new Image ( image.rescaled ( image.getWidth()/2, image.getHeight()/2) );
    encoderQueue->pushItem( imageCopy );
   frameCycle=0;
}

Any ideas?

2

Hi - anybody have any idea about this?

3

Thanks, it looks like that behaviour was buggy. I’ve pushed a change which should provide equivalent behaviour on iOS and macOS:

4

Hi. I tried this out (same code as above) and it’s not quite the same behaviour as in MacOS. What happens is it takes a continual stream of photos (about 2 per second) and you can hear the simulated shutter sound with each photo.

5

Just a quick update on this if anyone is watching - what I wanted was to capture video and stream H264, which isn’t what the module is intended for. Turns out that with a little hacking of the Juce code for recording video and a wrapper on the Video Toolbox, this works fine (although Video Toolbox is really obscure if you don’t know H264). Next stop Windows

1 Like