[mythtv-users] "aplay /dev/dsp" gives "Unsigned 8 bit" output?

[Joseph A. Caputo]

On Wednesday 05 November 2003 16:17, Gregor Hoffleit wrote:
> I'm running into frequent system hangs with MythTV, and I'm trying to
> find a way to track the cause down one by one.
>
> Audio appearently is a frequent cause of system hangs with MythTV. My
> TV card (some Pinnacle PCTV Studio Pro) doesn't support btaudio,
> therefore I have looped the TV audio output inside the AUX port of my
> sound card (some CMI-8738 based one). I'm using snd-cmipci of ALSA
> 0.9.6.
>
> Now if I set the mixer as described (capture and mute AUX), and run
> "aplay /dev/dsp", then all I get is 8 bit output, and obviously
> buffer overruns:
>
>     freefly:23> aplay /dev/dsp
>     Playing raw data '/dev/dsp' : Unsigned 8 bit, Rate 8000 Hz, Mono
>     xrun!!! (at least 13.151 ms long)
>     xrun!!! (at least 15.359 ms long)
>     xrun!!! (at least 15.490 ms long)
>     xrun!!! (at least 15.474 ms long)
>     xrun!!! (at least 15.486 ms long)
>
> The output in fact really sounds like 8 bit and 8000 Hz, compared to
> the TV output.
>
> First question: Why is that only 8 bit? Is that a limitation of the
> hardware (i.e. of the sound card), or is it some kind of
> configuration problem?
>

I have a CMI-8738-based sound card, and I seem to recall that in full 
duplex mode it splits the resolution to 8bit/8bit for record/playback.  
It can't do full 16-bit duplex.

[snip]

> My mainboard is a K7S5A (Rev.4). I don't trust the on-board sound as
> well, therefore I bought the CMI8738 card ;-).

That's funny... the CMI8738 was my on-board sound; I didn't trust/like 
it so I got a Hercules Fortissimo III (CS46XX-based).  Plus, I have 
btaudio, so everything's peachy :-)

-JAC