Backport MDEC fix?

[vanfanel]

Hi there @DarthMew

There is a long time issue with MDEC decompression that causes strange transparent rectangles in Resident Evil.
Here is the same problem in the FPGA MDEC implementation, which also comes from the same code base:
MiSTer-devel/PSX_MiSTer#260

Now, there is a commit that fixes that issue:

stenzek/duckstation@6d6659c

Could it be backported to Swanstation?

[DarthMew]

Implemented via b9bbf87

Be sure to check that "Use Old MDEC Routines" is turned off, as since 834a6f1 it is turned on by default for compatibility reasons.

[vanfanel]

Nice!

What compatibility reasons are there to not use the new MDEC routines? Could you point me to a game that has problems with them?

[vanfanel]

Ah, I understand now.. old MDEC routines are meant for texture substitution, etc.

Thanks!