Add an ioctl to return channel number (AUDIO_GETCHAN). This can be used
on audio/sound/audioctl devices.
Return EIO in read/write/ioctl/poll/stat if fp has been closed or is
invalid.
Update audio.4, audioio.h and audioctl(1) to reflect these changes.
instance per process. Virtual channels are placed in a queue, so there is
no longer a compile time limit of VAUDIOCHANS.
A new sysctl has been added to control multiple user access.
Mixer labels on virtual channels are now prefixed by vchan.
audiobell.c and audioctl have been updated to reflect these changes.
Use of fdclone was posted to tech-kern@ and improvements made.
Multiuser access control changes and the use of a queue were suggessted by
pgoyette@
posted to tech-kern:
* Simultaneous playback and mixing of multiple streams
* Playback streams can be of different encoding, frequency, precision
and number of channels
* Simultaneous recording to different formats
* One audio device per process
* Sysctls to set the common format frequency, precision and channels
* Independent mixer controls for recording/playback per stream
* Utilizes little cpu time for multiple streams / good performance
* Compatible with existing programs that use OSS/NetBSD audio
* Changes to audioctl(1) to allow specifying process id for corresponding
audio device
introduce a struct write_info for communication between front ends and
backends.
libaudio API is still pretty ugly, and needs to stay local here for now,
but it is a little more usable for other tools now.
if the stdout was same as the audio device. It's no longer relevant,
and the check was broken anyway (code used st_dev rather than st_rdev
when comparing the character devices).
A by-product of this is that 'audioctl -a > /dev/null' now works.
Okay'ed by Lennart.
andvar