WipEout (PS1 Classics) on the PSP - Why's it so small?!

[Amaroq Dricaldari]

I noticed that the Playstation Store copy of WipE'out" Classic is only 73 megabytes, give or take. However, my PSARDumper refuses to actually create a decrypted dump (like it should), and my PSX2PSP crashes when I try to extract an ISO from a PBP (the 'Convert to ISO' button doesn't work!), meaning I have no way of reverse-engineering the PS Store copy of WipEout and unlocking its secrets.

Obviously, the small file size has something to do with the music being re-encoded (allowing the game to be nearly 90% smaller), but that's as far as speculation is getting me. Any thoughts and/or help would be appreciated.

[Xpand]

The actual data size (without music) of the PS1 wipeout is around 25-30MB. So I guess they compressed the music or something.

[Amaroq Dricaldari]

Well, I know that already, the game itself is stored on a single .BIN track.

I'm not sure how it is with other ATRAC encoders, but GoldWave's ATRAC3 encoder uses a .WAV header, so a game might try to open it as CD audio. I guess the PS1 emulator for the PSP has a built-in ATRAC decoder that overrides the game's own decoder? (ATRAC is a lossy format, so it would make the game pretty small)