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POCrop CMSampleBufferRef
 

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    <p>I am trying to crop image in <code>CMSampleBufferRef</code> to a specific size. I am making 5 steps - 1. Getting <code>PixelBuffer</code> from <code>SampleBuffer</code> 2. Converting <code>PixelBuffer</code> to <code>CIImage</code> 3. Cropping <code>CIImage</code> 4. Rendering <code>CIImage</code> back to <code>PixelBuffer</code> 5. Attaching <code>PixelBuffer</code> to <code>SampleBuffer</code>. So far I am having trouble with step 4 - rendering image back to <code>PixelBuffer</code> (can not check beyond this point) nothing is rendered to buffer (I check it using same <code>CIImage imageWithCVPixelBuffer</code> and get NULL as a return). Would greatly appreciate any tip or help.</p> <pre><code>CGRect cropRect = CGRectMake(0, 0, 640, 480); CIImage *ciImage = [CIImage imageWithCVPixelBuffer:(CVPixelBufferRef)CMSampleBufferGetImageBuffer(sampleBuffer)]; //options: [NSDictionary dictionaryWithObjectsAndKeys:[NSNull null], kCIImageColorSpace, nil]]; ciImage = [ciImage imageByCroppingToRect:cropRect]; CVPixelBufferRef pixelBuffer; CVPixelBufferCreate(kCFAllocatorSystemDefault, 640, 480, kCVPixelFormatType_32BGRA, NULL, &amp;pixelBuffer); CVPixelBufferLockBaseAddress( pixelBuffer, 0 ); CIContext * ciContext = [CIContext contextWithOptions: nil]; [ciContext render:ciImage toCVPixelBuffer:pixelBuffer]; CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 ); CMSampleTimingInfo sampleTime = { .duration = CMSampleBufferGetDuration(sampleBuffer), .presentationTimeStamp = CMSampleBufferGetPresentationTimeStamp(sampleBuffer), .decodeTimeStamp = CMSampleBufferGetDecodeTimeStamp(sampleBuffer) }; CMVideoFormatDescriptionRef videoInfo = NULL; CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer, &amp;videoInfo); CMSampleBufferRef oBuf; CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer, true, NULL, NULL, videoInfo, &amp;sampleTime, &amp;oBuf); </code></pre>
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    1. This table or related slice is empty.
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    1. USRavi Gautam
    1. USLaz
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    1. This table or related slice is empty.
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      1. USinzan
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    1. COWhat is the problem you are having? I don't see a question here.
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      1. USAurelius
    2. COciContext is not rendering anything in buffer. I am checking it with the same ciimage imageWithCVPixelBuffer and get NULL
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      1. USLaz
 

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