Wipeout 3, Wipeout XL, Tobal no 1 and possibly other games corrupted audio when trying to loop last audio track

[McRmie]

Tested with a (Redump) USA version of Wipeout 3. Does not occur with SwanStation.

To test:

Start time trial -> Pick a class (probably doesn't affect the bug but I tested with 'Rapier') -> Pick your racing track (tested with 'Mega Mall') -> Pick your team/vehicle (tested with 'Feisar'). -> When the race start, pause the game and go to audio and select 'Xpander' as the audio track. -> Go back (still within the pause menu) and let the audio track play until the end (it's a little over 4 minutes).

When the audio track finishes playing, instead of restarting normally you just hear some kind of static, corrupted audio kind of sound. Tested with a few other audio tracks and it doesn't do this weirdly enough (perhaps because this audio track is the last one on the disc maybe?). It really is specific to 'Xpander'.

edit: Though that doesn't solve the underlying bug of course, you can circumvent the problem once the messed up audio starts by simply changing the tracks in the audio selection menu and that'll get rid of the glitchy audio.

edit: Just tested on the last standalone Mednafen release (1.32.1, I think) and the problem doesn't occur there. So I guess the libretro port would need to be updated for a fix.

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edit: Changed title.
It also occurs with Wipeout XL when you select track 11 in the game's options ('Body in Motion').

Whenever it tries to loop same thing happens. Audio is completely messed up. And that track also happens to be the final track on the game disc (I checked within the PlayStation audio player in the psx bios).

So this possibly happens on other games as well that tries to loop the final audio track on disc like that.

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Here is an audio capture of the glitch in beetle_psx_libretro.
Here is from SwanStation (no glitch).

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Also happens in Wipeout (1st game)

Just go to the options then select audio config and select "Transvaal" as the track -which is , again, the last track on disc and let it play until the end. The messed up audio will pop up soon after.

At this point I wonder if it only affects the PSX Wipeout games or does it affects any game that uses the same audio format (those that could be played in CD players).

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So, unfortunately, no:

The theme of Gren (the stage pictured above with the windmill things) is track 20 -last track on the disc. The glitch appears there as well. To test just start tournament mode. When you start the fight on that stage just pause (the music will continue playing) until the song reaches the end.

[McRmie]

Okay, did a bit of testing. The issue never happened on standalone mednafen: either the latest release or a really old one from 7 years ago. So that narrowed it down to the core...Tested with a fresh RA folder (also had OSD messages disabled in beetle_psx, which I should have re-enabled from the start) and the problem was fixed using pre cached CD access method...I was 99% certain changing to pre-cache access was the very first thing I tried, but, apparently not.

Even without using pre cache (so either using sync or asynchronous) as CD access method, the corrupted audio problem really did only occurred on the last track of the game for some reason however.

[McRmie]

Reopening this issue because while there is a workaround around the problem when using the 'CD access method = pre cache' option as mentioned above, I guess it's not really a "proper" fix and the problem is still present otherwise.

Also reopening because recently, notaz has fixed this on pcsx rearmed. And has provided some more information as to what was causing the issue. I know the cores are pretty different but I think what's causing the problem is related or similar.

Quick summary here.

So the problem occurs when the last audio track (in CD-DA or Redbook audio format) of the CD tries to loop after finishing playing, that's when you hear messed up audio with Beetle PSX. Something to do with the lead out area not being present in most CD images. The problem is not present in standalone Mednafen's PSX module/core.

The easiest way to test this is to simply use the in-built player of the PSX with games that have audio tracks that can be played normally in CD players and to let the track plays until the end (make sure the core option "CD access method" is not set to 'cache'). You can even use the fast forward while playing button to speed up the process. When the last audio track finishes playing, that's when you'll get the garbled audio.

[hizzlekizzle]

Does it make any difference if the disc image is in CHD format?

[McRmie]

No differences. I tested multiple formats: standard cue/bin, CHD, even tried the CCD format (Clone CD image with a .sub channel). Happens in all of them regardless.

edit: About the only thing left to try is a real PSX disc played from the CD/DVD drive (or a burned copy from a dumped image).

edit2: Very different system/core obviously but the Beetle Saturn core (also forked from Mednafen) does not show the problem in similar situations with the last CD-DA audio track.