Hi, can anyone please tell me exactly what I have to do to get alsa digital audio sound output working on kernel 2.6? As you might know kernel 2.6 versions come with their own version of alsa supplied, but I have tried everything imaginable to try to get digital out sound working and have had no luck at all. My soundcard is an onboard via8233 sound chip. (Which is extremely common - and as far as I understand it very well supported too). I have compiled in alsa support into the kernel and have selected my specific sound card in PCI devices, I have emerged (gentoo speak for installed) alsa-utils and alsa-OSS. I aked for advice on several forums, but no one seems to have a clue how to get digital out going on this card. One piece of advice I was given was that I should tell amixer to set IEC958 unmute and amixer set "IEC958 Playback AC97-SPSA" 0. However when I do that I get a message saying amixer: "Unable to find simple control 'IEC958',0" and amixer: Unable to find simple control "IEC958 Playback AC97-SPSA" 0 What does this mean? I also have three mixer channels which I have no idea what they are. They are all called "Via DXS". Can anyone exlplain what they do? If All I want is digital audio output and nothing else, what mixer controls should I mute and which should I unmute? I have been going at this trying to get digital out sound working in alsa for 4 weeks now and it's really starting to get me down. Surely there must be a way? All input is appreciated. Q

Lol, I'm sorry to have taken up your bandwidth, I surely don't mean to use up any more time and resources than you folks can afford. But 'piping sound out via any other audio capable cable' isn't really the answer I was hoping for. SPDIF passthrough - and digital sound in general - to an external dolby digital amplifier is a whole different kettle of fish than that, as it involves a considerable amount of post processing power on behalf of the digital amplifier. There is no true 5.1 (or indeed 7.1) audio playback - and subsequent channel seperation/decoding without some direct form of digital link. Without this all you get is a kind of dumb (literally) analoge reproduction of whatever the soundcard throws at it. There is no 'intelligent' processing at all. As for installing Red Hat, well I am a Gentoo Linux user... For better or for worse that is what I am... It has taken me 4 months to get Gentoo set up (its only rival in terms of difficulty to install is I think Linux from Scratch) and after having gotten everything else working, I'm not in the mood to give up now. But it does make me wonder... If Redhat could do it, then surely there must be a way? If you guys do have any clues, please let me know... Q PS, In case it's helpful, here is a list of the modules I currently have running in my kernel: bash-2.05b# lsmod Module Size Used by DAC960 75944 0 ide_floppy 18816 0 uhci_hcd 32912 0 snd_via82xx 25440 2 snd_ac97_codec 54404 1 snd_via82xx snd_mpu401_uart 7936 1 snd_via82xx snd_rawmidi 25376 1 snd_mpu401_uart snd_seq_device 8584 1 snd_rawmidi snd_pcm_oss 52644 0 snd_pcm 99108 4 snd_via82xx,snd_pcm_oss snd_page_alloc 12036 2 snd_via82xx,snd_pcm snd_timer 26116 1 snd_pcm snd 51428 10 snd_via82xx,snd_ac97_codec,snd_mpu401_uart,snd_rawmidi,snd_seq_device,snd_pcm_oss,snd_pcm,snd_timer soundcore 9664 1 snd via_agp 7168 1 agpgart 32552 2 via_agp fglrx 204292 150 ide_tape 55888 0 st 38296 0 bash-2.05b# Rick Taylor wrote:

Yes but... that seems to add another whole layer of complexity to what already seems like a complex state of affairs. How exactly would I pipe sound from a little onboard soundchip to a firewre port? My onboard sound doesn't have a firewire port... The only option after that is to pump the two remaining analoge sound channels to some kind of box, which then had firwire connections going... erm.. where exactly? Why wouldn't I just pump the two analoge channels directly to my amp? Except that would kind of defeat the purpose of what I'm trying to do. I think direct digital decoding is still preferable to any exotic solution such as 'network sound' or sound somehow pumped through a firewire port to somewhere (although sadly my amp doesn't have a firewire port either. It would be cool if it did though) though some kind of complex arrangement. I am sure a 'conventional' arrangement should be possible. The question is, as it was before, how? Q Rick Taylor wrote:

damn i was hoping you might be able to get to the bottom of this via82 nonsense :-) do you know which chipset it uses? the output of lspci will hopefully tell you. you can then match it against the list of modules (in /lib/modules/...). if you are lucky alsa may just load the correct module anyway.. cheers -- Tim Orford

Q <raid517(a)fairadsl.co.uk> wrote: Hardly... firewire is about as simple as it gets. Does your board? You can get firewire enabled amps. {Av, surround, etc} There may be a decoder of some sort. This would be networked digital. You could even do video with it.

Well thanks.. I would certainly appreciate any help anyone can offer. Yes I would have to say I agree with you on the Red Hat thing, although I was anxious not to piss off a lot of Red Hat users, particularly as this set up did work for sound in Red Hat. But I just couldn't cope with the dependency hell of Red Hat or any other RPM based distribution, so I started looking for an easy to manage distribution that would let me install and unistall software and updates without any of that hassle. Gentoo portage was that magic formula and after using it for a short while I was permenantly won over. It is a little ironic maybe that the easiest to use package management system in the Linux world comes included in the hardest to install linux distribution in the Linux world. (Slackware is nothing compared to Gentoo...) But oh well there you are. The end result is certainly worthwhile. It may have taken me a while to get my head around it, but persistance pays dividends and I came out of it knowing a lot more about Linux than I could have learned any other way. But as I said, I have never had sound and full 3D video working in any distibution I have tried (which is about eitht I think). right now I have every other feature working sweetly - except sound... If I could have sound I think I would celebrate by wiping all my windows partitions and instantly switching my 460GB of music, movies and games over to ext3 partitions. I want to be done with Windows and MS by this years end. Having sound would be a big step towards this goal. Q PS As for SPDIF cable. That isn't really an issue. I have high quality optical cable, which although in terms of benefit is probably only of at best an aesthetic value, at least gurantees a clear signal. (I assume you know that difference between optical and coaxil digital out is virtually irrelevant? In other words, it doesn't matter which of these is connected to the SPDIF out). Again any input anyone can offer on this would be much appreciated. It would for me be the culmination of a long held goal now (of over a year) to have both sound and video fully working in Linux. Q dwillis(a)stx.rr.com wrote:

On Wed, 08 Oct 2003 16:03:18 +0100, "Q" <raid517(a)fairadsl.co.uk> said: Hmm... perhaps this is why Linux isn't as prolific on the consumer desktop as a FOSS advocate might hope? All seriousness aside, I don't quite know how to help you. One possibility to entertain is that the current set of kernel-integrated drivers might be borked up. If it's not hernia inducing, consider compiling another kernel from the 2.4.X series and using an older version of ALSA with it; you could boot this one beside your normal kernel. This worked for me when I was assembling my brother's computer and faced some serious problems getting his onboard sound to work. YMMV. Peace, =Pete

On Wed, Oct 08, 2003 at 09:20:24AM +0100, Q wrote: i've just been through this myself on an Asus A7...? motherboard. I found it very educational installing Gentoo, and i think its v good, but man did it take me a long time! i tried 4 kernels and 4 versions of alsa and failed to get the via82xx sound working properly. After 2 days i gave up and it took about 10 mins to get a soundblaster working. i could be wrong but my feeling is the drivers for the via82xx are not good. I have had lockup problems in the past, but currently have it working fine for Gnomemeeting on an older mobo with alsa 0.9.0 (analogue) first it would be good if you could prove that digital out is actually implemented on your mobo. Have you had it working on older kernels or other OS's? Knoppix? Do you know for sure where the dig output comes out? separate panel? What are you using to test it? Do you have analogue out working? Is your outboard amp getting a carrier signal? i hate to say it but these mixers are not very helpful, and i find trial and error to be the best method. Run alsaplayer and try every possible combination. Often the controls dont do what you think, or what they are labeled as :-) which mixer are you using? you may find gnome-alsamixer or similar to be slightly more friendly than alsamixer. good luck with this. however, unless you're broke or are prone to geek perversity (not necc a bad thing!), perhaps the best advice would be to get a cheap pci card. cheers -- Tim Orford