VERY IMPORTANT - The Great Escape *.PSF (Xbox) by Mygoshi at 6:19 PM EDT on July 25, 2017
Ok so since 3 years I'm trying to know what's the codec used for this file and how to convert it into a playable format (like good settings for GENH). Is it possible to know? I think it's sort of IMA and uses 44100Hz for Frequency and Stereo. That's all I seem to know.
That byte at every offset 8 of the extracted files (in reality it's offset 0 because the first 8 bytes are the PSF header) reminds me to an adpcm codec I have already seen but don't remember what.
It's an unsupported codec. You can't create GENHs unless support is added into vgmstream. It looks like PS ADPCM without flags (coding_PSX_ADPCM_cfg), even though it's Xbox. Probably they just used the same ADPCM codec for all their games.