Slow MUNT emulation + no enhanced EGA

andy_blah · Post by **andy_blah** » Sun Aug 10, 2014 10:35 pm

So I compiled ScummVM myself on a x86 Debian-based distro, and whenever starting a game with MUNT (the one that comes with ScummVM), it keeps stuttering while this error floods the console:

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ALSA lib pcm.c&#58;7843&#58;&#40;snd_pcm_recover&#41; underrun occurred
ALSA lib pcm.c&#58;7843&#58;&#40;snd_pcm_recover&#41; underrun occurred
ALSA lib pcm.c&#58;7843&#58;&#40;snd_pcm_recover&#41; underrun occurred
ALSA lib pcm.c&#58;7843&#58;&#40;snd_pcm_recover&#41; underrun occurred

This doesn't happen with the distinct MUNT (that I've also built myself), working perfectly fine. Also it doesn't happen with any other sound source available.
Here's also an error message that might give a clue:

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WARNING&#58; SDL mixer output buffer size&#58; 940 differs from desired&#58; 4096!

I don't know of any option to modify the audio buffer size in ScummVM so I don't know what I could do to fix this.

And speaking of options, I remember ScummVM having an option to un-dither graphics in EGA games, but I don't have that option under Graphics in my build.

OS: CrunchBang 11 Waldorf x86 with testing Debian repos
ScummVM version: 1.7.0
config.log

Post by **digitall** » Mon Aug 11, 2014 7:19 am

You can not adjust that buffer size. That warning is telling us that libSDL has returned a buffer smaller than the requested size. You may have issues if that happens. I suspect the separate MUNT uses ALSA directly and probably avoids libSDL audio issues? This can occur with some embedded ac97 type drivers.

The undithered option is now a per engine option in the engine tab of games which support it.

andy_blah · Post by **andy_blah** » Mon Aug 11, 2014 6:11 pm

digitall wrote:I suspect the separate MUNT uses ALSA directly and probably avoids libSDL audio issues?

That's right. I was just using the external MUNT for reference. However other applications don't have any problems with libSDL when it comes to audio.

digitall wrote:This can occur with some embedded ac97 type drivers.

I'm using an integrated Intel 82801G (ICH9) audio controller, so I'm guessing that's what's causing it, but are there any fixes to this?

digitall wrote:The undithered option is now a per engine option in the engine tab of games which support it.

I'm having several EGA games (both Scumm and SCI) added to ScummVM and none of them show that option.

Post by **criezy** » Mon Aug 11, 2014 6:21 pm

andy_blah wrote:
digitall wrote:The undithered option is now a per engine option in the engine tab of games which support it.
I'm having several EGA games (both Scumm and SCI) added to ScummVM and none of them show that option.

I don't think this option was ever available for SCUMM games. For SCI games that supports it it is now available for me in the Engine tab when clicking on Edit Game.

m_kiewitz · Post by **m_kiewitz** » Tue Aug 12, 2014 9:48 am

andy_blah wrote:I'm having several EGA games (both Scumm and SCI) added to ScummVM and none of them show that option.

Undithering is only possible for true SCI EGA games. Which is all SCI games up to SCI01, including Quest For Glory 2 (which is SCI1 EGA).

For those games the option should sppear.

EGA versions of SCI1 VGA games are not supported (like for example King's Quest 5), because the backgrounds of those games weren't dithered by the SCI interpreter.