[Jack-Devel] Full-featured mixers

Tobias Hoffmann lfile-list at thax.hardliners.org
Sun Mar 31 19:17:31 CEST 2019


On 31/03/19 17:50, Tim wrote:
> Yes there is the envy24 mixer and Mudita24 (which I helped with).
> QasMixer does a good job of showing everything except the meters
>  that the other two mixers have.
> I seem to recall that the meters are actually ALSA components.
> Maybe they could be added to QasMixer.

I'm also using QasMixer, it seems to be one of only a few sane choices 
with apart from the text-mode alsamixer...

When I (re-)wrote the Focusrite Scarlett mixer driver (which has to 
expose a full 18x8 matrix; the original driver was done by Robin) to 
extend it to more devices, I also thought about the available metering 
information... but:
1) No mixer app seemed to actually support the alsa metering 
controls/components, so I would not be able to test it.
2) Unlike the gain controls, the soundcard exposes the metering data in 
blocks, so one block would contain the new data for (IIRC) *all* the 
matrix inputs, and another block would contain it for all the master 
outputs, and there was a third block - whereas the alsa controls expose 
the data *per channel*... this means extra work in the driver to split 
them (which also feels kind of wrong to me, from an api standpoint) ... 
or go the route some other devices went (IIRC envy24 mixer), and provide 
the data via the so called hw-dependent alsa api, which then 
necessitates a hw-dependent mixer app (i.e. is able to handle that 
specific hw-dep type).

Together with the rather spare documentation on the hw-dep stuff, that's 
when I decided not to pursue that feature any further...

   Tobias




More information about the Jackaudio mailing list