After last attempts, I took a new approach:
Editing:
- cinelerra to make a 3.5 min sequence
Render:
- separate the video and audio:
- cinelerra render video as mpeg video to small.mpv
- cinelerra render the audio as mpeg audio to small.mpa
Multiplex:
- mplex -v 0 -f 8 small.mpv small.mpa small.mpeg
Create iso image:
- dvdstyler: load small.mpeg
- make simple menu with "play" button.
- create iso image.
Burn iso image to DVD using gnome.
It works!