This issue has caused pcsx-df to be removed from Debian and Ubuntu, see the details here : http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514446
The problem is with file libpcsxcore/mdec.c with contains code from FPSE, a program with a restrictive license.
However there is a way to fix this issue, the mame emulator also has the mdec code, in a non restrictive license ( src/mame/machine/psx.c ) , please adapt your code so it can go back in Debian and Ubuntu.
nope, mame uses a non-free license as well so using code from mame doesn't make things better.
I hope I can have enough knowledge to rewrite the mdec stuff but not yet :(
also, the original authors of FPSE is not likely to be still reachable, so it would not be a good idea to ask for relicensing or clarification.
My guess is that there's not many ways to do a YUV to RGB convertion, it's a pretty standard formula.
I may be ok to move stuff around, rename variables so that the new code wouldn't look like the original one and remove any references to FPSE.
If mame also has a restrictive license, I think FFmpeg also has code that does the same thing.
I am looking at rewriting the code in mdec.c. While in the process I have found a couple of bugs that affect image quality and performance. Hopefully I will be able to post a patch in a few days.
Fixed in patch: https://sourceforge.net/tracker/index.php?func=detail&aid=2970060&group_id=204268&atid=988933