[alsa-devel] Surround problems with cs46xx

[Takashi Iwai]

At Tue, 19 Jun 2007 21:49:01 -0700,
Vasilis Manοlopoulos wrote:
> 
> 
> Thanks for the reply Takashi.
> I don't think that this is hardware problem, cause in windows XP, using 
> the drivers by the manufacturer Hercules, the sound is fine. About the 
> test you mentioned, I 'll check it when I find free time on weekend and 
> I 'll let you know the results. I hope you could provide me some further 
> help then. Unfortunately I am new in linux & sound issues, so creating a 
> 6 channel wav file and the whole procedure is a bit difficult to me and 
> it's better to deal with it in the weekend!!

Well, I didn't mean that your hardware is broken.  Rather I meant that
it's hardware-specific problem due to the current driver
implementation (three parallel streams without synchronization).


Takashi

> 
> 
> 
> Regards.
> 
> 
> 
> O/H Takashi Iwai έγραψε:
> > At Sat, 16 Jun 2007 16:56:53 +0300,
> > Vasilis Manwlopoulos wrote:
> >   
> >> Hi,
> >>
> >>
> >> Sorry for bothering the list again, but I have major problems with the 
> >> surround 5.1 sound. I have manually compiled/installed th latest 
> >> alsa-1.0.14 drivers but nothing improved. I am using Ubuntu 7.04 and my 
> >> soundcard is  the Hercules Fortissimo III. This is, as far as I know by 
> >> reading on Internet, supported by the module snd-cs46xx in ALSA. I have 
> >> enabled the surround sound by creating the following .asoundrc file.
> >>
> >> pcm.!default {
> >>     type plug
> >>     slave.pcm "surround51"
> >>     slave.channels 6
> >>     route_policy duplicate
> >> }
> >>
> >>
> >> The problem is that sound pauses whenever I try to do something "heavy" 
> >> such as opening a new firefox window or generally another app. Also, 
> >> there are delays and echo between the front and the rear speakers from 
> >> time to time. I think that the problem is that, this alsa setup(meaning 
> >> surround5.1 and the specific soundcard) places a heavy load on the cpu. 
> >> There are 99% cpu usage times when the only thing active is a player 
> >> playing a "normal bitrate" mp3. When I delete the .asoundrc file and I 
> >> switch to default stereo sound using only the 2 front speakers the 
> >> problems disappear.
> >>
> >> Can anyone suggest anything about this?
> >>     
> >
> > First, try to investigate whether it's a problem of surround51
> > implementation or rather the "default" definition above.
> > For example, prepare a 6-channel WAV file, and play directly with
> > surround51 PCM.
> >
> > But, from the symptom, I'm afraid it's rather a hardware problem.
> > The cs46xx uses three stereo streams for 5.1 output, and they are not
> > strictly synchronized.  And, debugging cs46xx driver is really a
> > nightmare...
> >
> >
> > Takashi
> >
> >   
>