Open Radar

 
Summary:
The documentation for imageWithCVImageBuffer doesn't tell what situations it returns NULL.  I'm seeing this reproducibly with a valid buffer, which could indicate that the API in question is simply broken, or it could indicate that there's some subtle precondition that I'm missing, and I have no idea which.

Steps to Reproduce:
To reproduce the problem trivially, grab the AVRecorder sample code project.  In the AVRecorderDocument.m file, add this method:

-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
    
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    assert(imageBuffer != NULL);
    CIImage *image = [CIImage imageWithCVImageBuffer:imageBuffer];
    assert(image != NULL);
}

Then declare that the class conforms to AVCaptureVideoDataOutputSampleBufferDelegate.  Finally, in its init method, add this:

	self.videoPreviewOutput = [[AVCaptureVideoDataOutput alloc] init];
        [self.videoPreviewOutput setSampleBufferDelegate: self queue:dispatch_get_main_queue()];
        [session addOutput: self.videoPreviewOutput];

right after:

        [session addOutput:audioPreviewOutput];

so that the method will get called.  The method reliably crashes at the second assert, i.e. imageWithCVImageBuffer is completely nonfunctional.  The same behavior occurs with the related initWith... method.


Expected Results:
I expected to get back a CIImage object.


Actual Results:
Got NULL.

Version:
10.9.2

Notes:


Configuration:
Current 15" Retina MacBook Pro (2.6 GHz)

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