On Tue, 4 Mar 2003, Jon Trulson wrote:

> On Tue, 4 Mar 2003, Scott Presnell wrote:
>
> >         blocksize sets the current audio blocksize.  The generic audio
> >         driver layer and the hardware driver have the opportunity to ad-
> >         just this block size to get it within implementation-required
> >         limits.  Upon return from an AUDIO_SETINFO call, the actual
> >         blocksize set is returned in this field.  Normally the blocksize
> >         is calculated to correspond to 50ms of sound and it is recalcu-
> >         lated when the encoding parameter changes, but if the blocksize
> >         is set explicitely this value becomes sticky, i.e., it is remains
> >         even when the encoding is changed.  The stickyness can be cleared
> >         by reopening the device or setting the blocksize to 0.
>
> 	AUDIO_SETINFO only appears to be used when dealing with a pc
> speaker in auvoxware...  Perhaps this needs to be used (or at least
> intialized to blocksize 0) on device open (before specifying format/sample
> rate) for netbsd?  Might be worth trying in the device open code...

On NetBSD OSS-audio is just a library that translates the OSS ioctl's
into native ones. The blocksize, for example, is rounded off to a
power of two and then set the ordinary way, because applications using
OSS expect that the blocksize must be a power of two. The audio layer
(which is itself an abstraction of the actual sound drivers) is more
flexible than OSS, so a native driver would possibly perform better,
and never worse.

Frederick