At Wed, 12 Dec 2007 16:04:37 -0700, Steve Strobel wrote: > > I am using a 4-input, 8-output codec (AD1938) in an application similar to a live sound mixing > board, where a combination of the input signals get mixed for each output. I can mix four > inputs to four outputs with a command like: > > arecord --file-type raw --channels=4 --format=S32_LE --rate=16000 \ > | crosspoint \ > | aplay --file-type raw --channels=4 --format=S32_LE --rate=16000 > > where crosspoint is a simple program that reads from stdin, does some mixing, and outputs > to stdout. > > My next step is to play and record wave files from the various channels, while the crosspoint > is running. For example, I might need to play message1.wav to channel 2 and message2.wav > to channel 3 while recording channel 1 to message3.wav. I am looking for advice about the > best way to accomplish that. > > It seems like it should be possible using a combination of dmix, snoop, and dshare, as follows: > - Use dsnoop to split the 4-channel input to the crosspoint and another virtual sound input, call it "A". > - Use dshare to split "A" into four mono sources. Then can use arecord normally to capture wave files. > - Use dmix and possibly dshare to similarly let the crosspoint continue to use the multi-channel > output while also providing a mono sound device for each channel that I can use with aplay. > > Am I on the right track, or would I be better off adding functionality to the crosspoint application > to read and write wave files? Thanks for any suggestions. Unfortunately this won't work. d* plugins can have only hw type slave PCM. So, dshare cannot have dsnoop as its slave. I recommend you to use simply JACK for such a purpose. It's exactly designed for this kind of work. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
