Merging two m4v Movie Files Using AVMutableComposition - Videos Will Not Merge

Question

I am using the below code to try and merge two m4v files stored in the documents folder :

CMTime insertionPoint = kCMTimeZero;
NSError * error = nil;

AVMutableC         


        

Answer 1

You havent set the composition to the exportSession.

After the line:

AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetHighestQuality];

Add this line

exportSession.videoComposition = composition;

This should solve your problem.

Answer 2

Ok - so I eventually got this working by using individual AVMutableComposition tracks and then setting a mutablecomposition for audio and one for video.