[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: mp3 players

Theo de Raadt <deraadt_(_at_)_cvs_(_dot_)_openbsd_(_dot_)_org> wrote:

> How about a kernel solution.
> Instead of always rounding up, we can make the code round to farthest
> thing.

There is no single rounding function in the kernel, it's in the
hands of the individual drivers.  Most modern hardware goes through
dev/ic/ac97.c.  The rounding up is incidental for hardware that
requires inverted values; rather than ~vol ac97_mixer_[gs]et_port()
does vol=255-vol.

(Interestingly, the minimum delta is available in struct mixer_devinfo,
although at first glance only ac97 and uaudio bother to fill it in,
and of course it is not available through the libossaudio interface
most mixer apps use.)

Christian "naddy" Weisgerber                          naddy_(_at_)_mips_(_dot_)_inka_(_dot_)_de