How can I know whether camera supports a resolution or not in mac os x

Question

I am working on a project and recently switch to objective c for a small period of time. I am facing some problem in mac osx while capturing video from camera using qtkit. I am currently using "setPixelBufferAttributes" to set different properties of captured video. The problem is :

1. If camera does not support 640 X 360 resolution and i am setting it using "setPixelBufferAttributes" then also video is captured and internally converted to 640 X 360 Which I dont need. So I don't want automatic conversion of resolutions.

2. I want all supported resolutions supported by camera hardware directly.

Please guide me if any other API is also present...

Answer 1

This code will enumerate the size of the video source from the QTCaptureDevice :

    [captureDevice.formatDescriptions enumerateObjectsUsingBlock:^(QTFormatDescription* formatDescription, NSUInteger idx, BOOL* stop) {
        NSDictionary* attributes = [formatDescription formatDescriptionAttributes];
        NSValue* videoEncodedPixelsSize = [attributes objectForKey:@"videoEncodedPixelsSize"];
        NSSize videoSize = [videoEncodedPixelsSize sizeValue];
        NSLog(@"%@", NSStringFromSize(videoSize));
    }];