how to convert a CVImageBufferRef to UIImage

Question

I am trying to capture video from a camera. i have gotten the captureOutput:didOutputSampleBuffer: callback to trigger and it gives me a sample buffer that i th

Answer 1

If you simply need to convert a CVImageBufferRef to UIImage, it seems to be much more difficult than it should be. Essentially you need to convert to CIImage, then CGImage, THEN UIImage. I wish I could tell you why. Who knows.

-(void) screenshotOfVideoStream:(CVImageBufferRef)imageBuffer
{
    CIImage *ciImage = [CIImage imageWithCVPixelBuffer:imageBuffer];
    CIContext *temporaryContext = [CIContext contextWithOptions:nil];
    CGImageRef videoImage = [temporaryContext
                             createCGImage:ciImage
                             fromRect:CGRectMake(0, 0,
                             CVPixelBufferGetWidth(imageBuffer),
                             CVPixelBufferGetHeight(imageBuffer))];

    UIImage *image = [[UIImage alloc] initWithCGImage:videoImage];
    [self doSomethingWithOurUIImage:image];
    CGImageRelease(videoImage);
}

This particular method worked for me when I was converting H.264 video using the VTDecompressionSession callback to get the CVImageBufferRef (but it should work for any CVImageBufferRef). I was using iOS 8.1, XCode 6.2.