cmsamplebufferref

I am trying to crop and scale a CMSampleBufferRef based on user's inputs, on ratio , the below code takes a CMSampleBufferRef, convert it into a CVImageBufferRef and use CVPixelBuffer to crop the internal image based on its bytes. The goal of this process is to have a cropped and scaled CVPixelBufferRef to write to the video - (CVPixelBufferRef)modifyImage:(CMSampleBufferRef) sampleBuffer { @synchronized (self) { CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); // Lock the image buffer CVPixelBufferLockBaseAddress(imageBuffer,0); // Get information about the image

I noticed in the iOS documentation for AVAssetWriterInput you can pass nil for the outputSettings dictionary to specify that the input data should not be re-encoded. The settings used for encoding the media appended to the output. Pass nil to specify that appended samples should not be re-encoded. I want to take advantage of this feature to pass in a stream of raw H.264 NALs, but I am having trouble adapting my raw byte streams into a CMSampleBuffer that I can pass into AVAssetWriterInput's appendSampleBuffer method. My stream of NALs contains only SPS/PPS/IDR/P NALs (1, 5, 7, 8). I haven't

I need to obtain the UIImage from uncompressed image data from CMSampleBufferRef. I'm using the code: captureStillImageOutput captureStillImageAsynchronouslyFromConnection:connection completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) { // that famous function from Apple docs found on a lot of websites // does NOT work for still images UIImage *capturedImage = [self imageFromSampleBuffer:imageSampleBuffer]; } http://developer.apple.com/library/ios/#qa/qa1702/_index.html is a link to imageFromSampleBuffer function. But it does not work properly. :( There is a

This has bothering me for a while. i have video convert to convert video into “.mp4” format. But there is a crash that happens on some video but not all. here is the crash log *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[AVAssetWriterInput appendSampleBuffer:] Cannot append sample buffer: First input buffer must have an appropriate kCMSampleBufferAttachmentKey_TrimDurationAtStart since the codec has encoder delay' here is my codes: NSURL *uploadURL = [NSURL fileURLWithPath:[[NSTemporaryDirectory() stringByAppendingPathComponent:[self getVideoName]]

I'm getting a UIImage from a CMSampleBufferRef video buffer every N video frames like: - (void)imageFromVideoBuffer:(void(^)(UIImage* image))completion { CMSampleBufferRef sampleBuffer = _myLastSampleBuffer; if (sampleBuffer != nil) { CFRetain(sampleBuffer); CIImage *ciImage = [CIImage imageWithCVPixelBuffer:CMSampleBufferGetImageBuffer(sampleBuffer)]; _lastAppendedVideoBuffer.sampleBuffer = nil; if (_context == nil) { _context = [CIContext contextWithOptions:nil]; } CVPixelBufferRef buffer = CMSampleBufferGetImageBuffer(sampleBuffer); CGImageRef cgImage = [_context createCGImage:ciImage