stitch from cameras

could someone provide insights on how to stitch from cameras?
Thanks

hi, it seems that I manage to execute nvstitch sample on 8 mp4 inputs recorded from gstreamer as h264;
However, the resulting file seems to have some issue with probable codecs; https://worldexchange.s3.amazonaws.com/out_stitched.mp4
Is it complicated to reduce the number of inputs to 4? I tried to modify xml files, but that hasn’t worked out in my case