By default AVStoDVD uses the following HQ parameters when the FFMpeg HQ mode is activated:
-bf 2 -mbd rd -trellis 2 -cmp 2 -subcmp 2
These parameters are officially recommended, see here:
https://ffmpeg.org/faq.html#Which-ar...PEG_002d2_003f
But at least for current versions of FFMpeg the "trellis" parameter causes heavy artifacts with a lot of sources. It looks like the background is "pulsing", the reason is that all I-frames are bitrate-starved, i.e. their quantizer is way too high.
Here is an example source file:
http://www67.zippyshare.com/v/PpKnauBU/file.html
Even with the highest bitrate these artifacts are clearly visible. Removing the "-trellis 2" from the HQ parameters fixes the problem.
Thanks to SilverSolver from the DVDStyler forum for discovering the issue and being a great help in finding the culprit.
I recommend to everyone to remove the "trellis" parameter from the HQ FFMpeg parameter list...
Cheers
manolito