Exporting AVAssetExportSession video files with multiple audio tracks

I am using AVAssetExportSession

c AVMutableComposition

to create one video file from three video files.

When checking the output video file, Quicktime

there are two audio tracks.

1. 2ch 44,100
2. 1ch 44,100

      

        
        
        
      

    

How to export using AVAssetExportSession

so that the exported video has only one audio track, as this causes an issue when the video is displayed outside of iOS.

I used SDAVAssetExportSession

one that does what I need, but it has some reliability issues as seen from the Github issues for the project, so I'd rather just use AVAssetExportSession

.

thank