AVMutableCompositionTrack - insertTimeRange - insertEmptyTimeRange issue

Question

I have a strange problem: I want to generate a new sound file out of two soundfiles and silence.

sound1: 2 seconds long + silence: 2 seconds silence + sound2: 2 seco

Answer 1

Not sure if its late,

insertEmptyTimeRange : If you insert an empty time range into the track, any media that was presented during that interval prior to the insertion will be presented instead immediately afterward.

So all you have to do is add both the clips first and then add the emptytime range at time 2. This should work

insertTimeRange(0 to 2)
insertTimeRange(2 to 4)
insertEmptyTimeRange(2 to 4)