I join 3 video files using avconv and create a intermediate file, using following syntax
cat inter1.mpg inter2.mpg inter3.mpg > interAll.mpg
inter1.mpg,inter2.mpg contains no audio track.
After create a interAll.mpg I convert it to a mov file using following syntax
avconv -i interAll.mpg output.mov
My problem is, the audio track of inter3.mpg overlaying with video track of innter2.mpg in output.mov