[alsa-devel] asihpi: Control naming

Eliot Blennerhassett linux at audioscience.com
Thu Sep 30 05:44:14 CEST 2010

Hi all,

I'm struggling with getting the correct names for controls, so that they
show up correctly in the Playback or Capture modes of alsamixer

E.g. "PCM 3 Capture Meter" appears in the playback controls?

How is capture vs playback display determined?
or to put it another way: What are the rules for creating control names.

Here is a reduced schematic of one of our cards (in reality more
channels e.g. 4 physical stereo ins and outs, 12 players, 8 recorders)
All players and inputs are mixed to outputs.
All inputs and players multiplexed to each capture.

How should all these controls be named?

                                          | |
                                 .-[vol]--' |

[linein0]-[level]-\                     \
[digitalin0]------/              |    mux >--[mode]--[meter]--[cap0]
                                 |    ,../
                                 |   |
[linein1]-[level]-\                  |   >--[mode]--[meter]--[cap1]

[level] means calibrated reference level setting in dBu
[mode] stereo channel modifier
+ summing junction
--|-- wires cross, no join
(1) connect from input to matrix mix output

thanks and regards

Eliot Blennerhassett
AudioScience Inc.

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