On Sat, 29 Apr 2006 13:21:22 +1200 Neil Stockbridge <[EMAIL PROTECTED]> wrote:
> On Fri, 2006-04-28 at 11:59 +1200, Stephen Irons wrote: > > It is not clear to me how various things work together (or not) in linux > > to make sound work. There seem to be too many layers and alternatives: > > alsa, oss, esd, jack? > > OSS is a known interface between application software and physical sound > cards and includes OSS kernel drivers for each sound card. ALSA is > similar and has mostly made OSS obsolete. ESD is another interface but > one that sits on top of either OSS or ALSA and mixes audio from multiple > applications (OSS and ALSA support only one application using the sound > card at once i think). no longer true of alsa - dmix allows mixing of different sources. http://gentoo-wiki.com/HOWTO_ALSA_sound_mixer_aka_dmix has alot of info. Also note that although OSS is deprecated, and alsa is now integrated with the kernel, there are plenty of apps that want to output to oss drivers. Those drivers make a device at /dev/dsp (or similar) that you can output to. Because so many apps depend on the oss driver being present, alsa has oss emulation included. Here is a typical list of modules installed on a modern (2.6) kernel with oss emulation included: [EMAIL PROTECTED] ~/media/audio/bbcjazz $ lsmod|grep snd snd_pcm_oss 47392 0 snd_mixer_oss 17024 1 snd_pcm_oss snd_seq_oss 32128 0 snd_seq_midi_event 6400 1 snd_seq_oss snd_seq 49488 4 snd_seq_oss,snd_seq_midi_event snd_via82xx 22688 0 snd_ac97_codec 78392 1 snd_via82xx snd_pcm 82120 3 snd_pcm_oss,snd_via82xx,snd_ac97_codec snd_timer 21124 2 snd_seq,snd_pcm snd_page_alloc 7620 2 snd_via82xx,snd_pcm snd_mpu401_uart 6144 1 snd_via82xx snd_rawmidi 20512 1 snd_mpu401_uart snd_seq_device 6988 3 snd_seq_oss,snd_seq,snd_rawmidi snd 46692 11 snd_pcm_oss,snd_mixer_oss,snd_seq_oss,snd_seq,snd_via82xx,snd_ac97_codec,snd_pcm,snd_timer,snd_mpu401_uart,snd_rawmidi,snd_seq_device soundcore 7456 1 snd the OSS stuff is self evident. Anyway - back to "why don't I have sound" first check what modules are loaded - lsmod|grep snd next check the device permissions on /dev/dsp. It will probably be owned by root and a group like "audio" or "media" - make sure that the user is in the correct group. DO NOT change the ownership, it will revert on the next boot! Put yourself into that group, log out. log in. (group changes take effect from the next login - apain when you are in X) > > what's jack? > Jack Audio Connect Kit Pro level low latency audio system. If you want to set up a linux music making machine (synth, drum machine, midi etc etc ) you need jack. or so they tell me! > > I did notice from /proc/interrupts that interrupt 11 is shared between > > the soundcard and the PCI-based USB card, and the number of interrupt > > events for interrupt 11 is zero. This suggests some sort of conflict > > between the sound card and the USB card at the interrupt level. > > > > 4. I thought that PCI was meant to have solved interrupt sharing? > > > > I have the BIOS set to non-PnP operating system, with resources > > allocated automatically. > > > > 5. Do I need to change this? > > did you change this and did it make any difference? > > - neil > >
