How to set timestamp of CMSampleBuffer for AVWriter writing

Question

I\'m working with AVFoundation for capturing and recording audio. There are some issues I don\'t quite understand.

Basically I want to capture audio from AVCaptureSessio

Answer 1

Chunk of sample code from here: http://www.gdcl.co.uk/2013/02/20/iPhone-Pause.html CMSampleBufferRef sample - is your sampleBuffer, CMSampleBufferRef sout your output. NewTimeStamp is your time stamp.

CMItemCount count;
CMTime newTimeStamp = CMTimeMake(YOURTIME_GOES_HERE);
CMSampleBufferGetSampleTimingInfoArray(sample, 0, nil, &count);
CMSampleTimingInfo* pInfo = malloc(sizeof(CMSampleTimingInfo) * count);
CMSampleBufferGetSampleTimingInfoArray(sample, count, pInfo, &count);
for (CMItemCount i = 0; i < count; i++)
{
    pInfo[i].decodeTimeStamp = newTimeStamp; // kCMTimeInvalid if in sequence
    pInfo[i].presentationTimeStamp = newTimeStamp;

}
CMSampleBufferRef sout;
CMSampleBufferCreateCopyWithNewTiming(kCFAllocatorDefault, sample, count, pInfo, &sout);
free(pInfo);