Hacking usb/uaudio code

[Kazuhito HONDA]

I'm sorry that I didn't search mailing-lists and I didn't find your works
in which uaudio codes in NetBSD was merged into FreeBSD.
I have already sent PRs which include merged uaudio codes 
and some suitable codes for FreeBSD sound system.

kern/75274 for merging
kern/75276 for volumes
kern/75311 for recording
kern/75316 for selection of a recording sound source

without sampling rate changer.

Would you please deal with them as you like.


And several my expectation:
I use Sound Blaster Digital Music (Creative Labs.).
Its sampling rate are 48 kHz for playback 
and 48 kHz and 44.1 kHz for recording, so fixed.
I guess that rates of many USB audio devices are fixed.
NetBSD sound system has sampling rate and encoding changer 
(src/sys/aurateconv.c). 
But I expect that it is difficult to merge the changer into FreeBSD
because it may include improvement of the base 
of the FreeBSD sound system, probably.
And I can't find a way to merge its codes into uaudio only.
So I had better use esd -r and sox.

On the other hand, new uaudio codes are not almighty.
I don't have but Mr. kent, NetBSD committer, has Sound Blaster Audigy 2 NX.
It has 9 volumes (features) and 3 selectors with 3 inputs and 4 outputs.
Mr. kent worked hard to let NetBSD identify roles of these features.
But I guess almost features can't be identified 
in more complicated USB sound devices.
Besides, it may be supposed in FreeBSD sound system 
that sound devices have simple systems like Sound Blaster.
This limitation makes it difficult to control several features separately.
So I expect that not general uaudio codes but specified audio codes 
are applied to complicated USB audio devices.

Kazuhito HONDA
kazuhito at ph.noda.tus.ac.jp