CVS commit: src/lib/libossaudio

["Nia Alarie" <nia%netbsd.org@localhost>]

Module Name:    src
Committed By:   nia
Date:           Sat Oct 17 23:23:06 UTC 2020

Modified Files:
        src/lib/libossaudio: ossaudio.c soundcard.h

Log Message:
ossaudio(3): Add initial support for the OSSv4.1 Mixer API

One or two calls from this API were supported previously and have been
moved to the correct place.

Mapping the controls correctly is a difficult task. There is a define
hidden in the OSS headers that would allow an AUDIO_MIXER_SET control
to be represented perfectly, but it seems to _only_ exist there, and
no software supports it. So for now only one member of a set can be
set at a time - unfortunate. I've hidden code that should unlock
doing this the proper way under #notyet.

I'm not too happy with the way this code is managing file descriptors.
Currently it has to open a new fd for each ioctl due to OSSv4 deciding
to specify the device number in a structure rather than in the filename.
In the future, we could reuse the file descriptor if the correct one is
detected open.

This allows the mixer programs provided with the OSSv4 sources to compile
and work cleanly. I've observed problems with it failing to work on
secondary devices, and should investigate this later. There may be
a fd leak somewhere.


To generate a diff of this commit:
cvs rdiff -u -r1.48 -r1.49 src/lib/libossaudio/ossaudio.c
cvs rdiff -u -r1.25 -r1.26 src/lib/libossaudio/soundcard.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.