[vox-tech] Skipping sound

[Peter Jay Salzman]

begin Samuel Merritt <spam@andcheese.org> 
> Running twm, mpg123 in an xterm, and Mozilla with X niced to 0, the
> sound still skips when I scroll in Mozilla.
> 
> The skipping even happens with "play" (wave file player), and this
> machine is grossly overpowered for just playing music and running X, so
> I doubt it's a CPU time issue. 
 
kay.  wasn't sure what kind of machine it was.

> I'm actually running Mandrake 9.0 on the machine in question, and X
> started out niced to -10. 
 
stupid question.  you looked at top while moving a window around?
did you see anything interesting?

also, is this a new symptom?  or has it always been happening and you
just now sent an email out about it?

> Also, I forgot to mention earlier that I've ruled out an IRQ conflict.
> Theoretically, since they're both PCI devices, the sound and video cards
> should be able to share an IRQ, but I moved the video card around to
> ensure that they're on different IRQs. 

i don't think every video card uses irq.   some video cards get polled
by the CPU and fetch data by explicit read accesses to I/O memory.
voodoo 4/5, 1/2 and mach cards are like this.  don't know about matrox.
but you should be able to tell using lspci -vb.

odd.  i guess i'm most curious about the "is this something new or has
always been a problem" question.

pete


> On Wed, Feb 26, 2003 at 12:38:13PM -0800, Peter Jay Salzman wrote:
> > sam,
> > 
> > have you tried with a different window manager?   do you get the
> > skipping around when you use mp3blaster/mpg123 under twm?   that might be a
> > good litmus test.
> > 
> > also, you run debian, right?  see if the "X" process is un-niced.
> > debian now asks you if you want to run X with a higher priority.
> > 
> > try to renice X to 0.  see if that helps the skipping around.
> > 
> > pete
> > 
> > 
> > begin Samuel Merritt <spam@andcheese.org> 
> > > If I have music playing and I move a window around, switch windows, or
> > > scroll a window, the music stutters. I'm using XFree86 4.2.1 and ALSA
> > > 0.9.0rc2 (defaults for Mandrake 9). 
> > > 
> > > This happens in any video mode I try, from 1024x768, 24bpp down to
> > > 640x480, 8bpp, though the stuttering is worse in higher resolutions and
> > > color depths.
> > > 
> > > I've also tried switching between ALSA and OSS. It makes no difference. 
> > > 
> > > The video card is a Matrox Mystique with 4MB video RAM (MGA 1064SG). 
> > > The sound card is an onboard CM8738. 
> > > 
> > > I'd heard about problems like this years ago, having to do with the
> > > video card drivers hogging the PCI bus for long periods of time. I
> > > played with the option "PciRetry", found in the mga(4) man page. The
> > > stuttering is the same whether this option is on or off. 
> > > 
> > > Google doesn't come up with any relevant results; I did find a whole
> > > bunch of pages about a setting that goes in system.ini, but I don't have
> > > one of those. =)
> > > 
> > > 
> > > -- 
> > > Samuel Merritt
> > > OpenPGP key is at http://meat.andcheese.org/~spam/spam_at_andcheese_dot_org.asc
> > > Information about PGP can be found at http://www.mindspring.com/~aegreene/pgp/
> > 
> > 
> > 
> > -- 
> > First they ignore you, then they laugh at you, then they fight you,
> > then you win. -- Gandhi, being prophetic about Linux.
> > 
> > Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D
> > _______________________________________________
> > vox-tech mailing list
> > vox-tech@lists.lugod.org
> > http://lists.lugod.org/mailman/listinfo/vox-tech
> 
> -- 
> Samuel Merritt
> OpenPGP key is at http://meat.andcheese.org/~spam/spam_at_andcheese_dot_org.asc
> Information about PGP can be found at http://www.mindspring.com/~aegreene/pgp/



-- 
First they ignore you, then they laugh at you, then they fight you,
then you win. -- Gandhi, being prophetic about Linux.

Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D