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Old 13th March 2016, 11:53   #2918  |  Link
manolito
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Join Date: Sep 2003
Location: Berlin, Germany
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Problem with default FFMpeg HQ parameters

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
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