Hold multiple Frames in Memory before sending them to AVAssetWriter

Question

I need to hold some video frames from a captureSession in memory and write them to a file when \'something\' happens.

Similar to this solution, i use this code to put a

Answer 1

You're supposed to lock base address before accessing imageBuffer's properties.

CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer, 0);
uint8 *baseAddress = (uint8*)CVPixelBufferGetBaseAddress(imageBuffer);
NSData *rawFrame = [[NSData alloc] initWithBytes:(void*)baseAddress length:(height * bytesPerRow)];
[m_frameDataArray addObject:rawFrame];
CVPixelBufferUnlockBaseAddress(imageBuffer, 0);