Roman Bogorodskiy

Current trunk works fine with both sndio 1.7.0 (buggy) and 1.8.1 (not buggy).

Previous comment appears to be still relevant.

I can see [src/libout123/modules/sndio.c:guess_channels():124] debug: maximum device channels: 8 with sndio not patched. I had to make some minor changes to make it work. Apparently, it's not allowed to call sio_getcap() after sio_setpar() failing, That's also what the man page says: Error handling Errors related to the audio subsystem (like hardware errors, dropped connections) and programming errors (e.g. call to sio_read() on a play- only stream) are considered fatal. Once an error occurs, all...

I can see [src/libout123/modules/sndio.c:guess_channels():124] debug: maximum device channels: 8 with sndio not patched. I had to make some minor changes to make it work. Apparently, it's not allowed to call sio_getcap() after sio_setpar() failing, That's also what the man page says: Error handling Errors related to the audio subsystem (like hardware errors, dropped connections) and programming errors (e.g. call to sio_read() on a play- only stream) are considered fatal. Once an error occurs, all...

Not sure if you're thinking out loud or asking me. If latter, I'm afraid I'm not qualified enough to provide a reasonable answer. I can test stuff on my machine though. For instance, on my box sndio reports the following capabilities: (09:39) novel@kloomba:~/code/sndio/examples[master] %> ./cap config 0 enc: u8 s16le s16be s24le3lsb u24le3lsb s32le u32le pchan: 1 2 4 6 8 rchan: 1 2 4 6 8 rate: 8000 11025 12000 16000 22050 24000 32000 44100 48000 64000 88200 96000 192000 (09:40) novel@kloomba:~/code/sndio/examples[master]...

That should work, I guess. It looks like we can also use sio_getcap() to make sure 2 channels are supported.

Are you still talking about upstream as sndio or FreeBSD OSS? From what I can see, there's no special treatment of pchan == 0 in sndio, only comparison with the trap value (~0U). In OSS it looks like the set channels ioctl just writes back current number of channels if the supplied value is 0: https://cgit.freebsd.org/src/tree/sys/dev/sound/pcm/dsp.c#n1515, which appears to be safe enough.

This is now fixed in sndio git: https://github.com/ratchov/sndio/commit/aac840d9f91c52a1dc3dcbdbfc3c628a80a717a1. Looks like the issue can be closed now. Not sure if the "par.pchan = 0" workaround should be kept or just wait while users eventually move to a newer sndio version that has that issue fixed. Thanks