Re: [linux-audio-user] Common linux audio layer

Greetings: I've been following this thread since it began. IIUC the original question was something like: "I want to run a number of audio apps simultaneously but [Linux, ALSA, SCO] won't allow it on my system". Again, if I understand the issue correctly, it seems that we're discussing audio stream multiplexing. Now, on cards like the SBLive we get what's called hardware mixing, a nicely transparent technology that lets me run multiple soundapps without doing anything extra to make it happen. You *can* do this in software, and as Lee points out the ALSA dmix plugin will do it. My laptop includes a NeoMagic 256A/V audio/video chip, i.e., no hardware mixing. So under normal circumstances I get to use one soundapp at a time. Here's my $HOME/.asoundrc file that gives me software audio multiplexing : ######################################################### # # asoundrc file to demonstrate use of ALSA dmix plugin # pcm.!default { type plug slave.pcm "dmixer" } pcm.dmixer { type dmix ipc_key 1024 slave { pcm "hw:0,0" period_time 0 period_size 1024 buffer_size 4096 rate 44100 } bindings { 0 0 1 1 } } ctl.dmixer { type hw card 0 } ########################################################## An example usage might look like this: xine -A alsa foo.mpg aplay -f cd -D default foo.wav Performance is improved on my machine (a PII 366) if I change the sample rate to 32000. At 44.1 kHz the little box just barely keeps up whie playing a movie at the same time I run a major soundapp. There are probably other interesting tweaks, but this example might get someone started in the right direction. I think the Windoze system audio mixer does the same thing as dmix but rather transparently. It is a pain to have to write a specific asoundrc file, but it's not an awful pain... (dp thanks Takashi Iwai for explaining dmix to him over and over again...) Best, dp tim hall wrote: