[LAD] mudita24 summing pct outs

David Santamauro david.santamauro at gmail.com
Mon Sep 13 19:47:35 UTC 2010


I was playing with alsa arecord and daring to brave a .asoundrc for my
delta 1010. I set up a multi-out and monitor mix to grab the digital
mixer output [1]

pcm.delta1010 {
  type hw
  card M1010
  device 0
}

# send to all outputs:
pcm.multi {
  type plug
  ttable.0.0 1
  ttable.0.1 1
  ttable.0.2 1
  ttable.0.3 1
  ttable.0.4 1
  ttable.0.5 1
  ttable.0.6 1
  ttable.0.7 1
  ttable.0.8 1
  ttable.0.9 1
  slave.pcm delta1010
}

pcm.mix {
  type plug
  ttable.0.10 1 # digital mix left
  ttable.1.11 1 # digital mix right
  slave.pcm delta1010
}


Monitoring with mudita24, I see the individual levels well below +0 but
the digital mixer showing OVER (well, peaked).

2 questions: 1) is this correct to sum the individual pcms (seems
that's what it's doing) and 2) is that even correct? recording with

 arecord  -c2 -r44100 -d10 -fS32_LE -V stereo

never showed OVERs.

Any insight?

thanks
David


[1] http://alsa.opensrc.org/index.php/1712_.asoundrc




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