Opened 15 years ago

Last modified 5 years ago

#9058 new patch

Using more than one FM_OPL object (experimental)

Reported by: eriktorbjorn Owned by:
Priority: normal Component: Engine: SCUMM
Version: Keywords:
Cc: Game: Indiana Jones 4


This patch started out as an attempt to fix bug #2545447 ("MI2: Waterfall sound breaks up") by using two FM_OPL objects instead of one. In other words, it simulates having two AdLib sound cards cooperating to play the music. However, it turns out that it doesn't fix the bug, it just postpones it a bit. It also turned out that the patch only works with MAME's emulator, not DOSBox's. That's when I decided not to finish the patch, so right now you have to set the _numCards variable to either 1 or 2 and then recompile.

On the other hand, it does keep the music from cutting out during the Fate of Atlantis endgame, so I didn't want to throw it away either. But maybe there's a simpler way to achieve the same thing? DOSBox's emulator has some references to OPL3, and I guess using that would double the number of channels too. (OPL3 has some other features too, but I don't know if any of the games that ScummVM supports know how to take advantage of that.)

Ticket imported from: #2827392. Ticket imported from: patches/1163.

Attachments (3)

opl-experiment.diff (15.7 KB ) - added by eriktorbjorn 15 years ago.
Patch against current SVN trunk
atlantis-1card.ogg (60.7 KB ) - added by eriktorbjorn 15 years ago.
Recording without patch
atlantis-2card.ogg (60.6 KB ) - added by eriktorbjorn 15 years ago.
Recording with patch

Download all attachments as: .zip

Change History (7)

by eriktorbjorn, 15 years ago

Attachment: opl-experiment.diff added

Patch against current SVN trunk

comment:1 by lordhoto, 15 years ago

About that Indy4 issue you mention? Is there any bug report for that? And does it happen with the original interpreter? After all that only had one AdLib too.

by eriktorbjorn, 15 years ago

Attachment: atlantis-1card.ogg added

Recording without patch

by eriktorbjorn, 15 years ago

Attachment: atlantis-2card.ogg added

Recording with patch

comment:2 by eriktorbjorn, 15 years ago

I don't think there's any bug report about the Fate of Atlantis problem. I always assumed it happened in the original too, but I haven't checked.

It's not a bad problem, really. It's just some notes that get cut off early. Particularly near the end, where there are lots of Adlib sound effects as well. I've made two recordings (deliberately low quality to keep the file sizes down) to illustrate one such instance.

comment:3 by digitall, 6 years ago

Component: --Other--

comment:4 by digitall, 5 years ago

Component: --Other--Engine: SCUMM
Game: Indiana Jones 4
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