[alsa-devel] Why there is no SNDRV_PCM_RATE_24000 in pcm.h

[Wei Kai]

Thank you, Clemens.

2007/8/10, Clemens Ladisch <cladisch at fastmail.net>:
> Wei Kai wrote:
> > I checked the include/sound/pcm.h in kernel and find this problem, it
> > seemed strange, so many codecs support the 24000 sample rate, why
> > there is no such definition.
>
> When the header file was created many years ago, 24000 Hz wasn't a
> common sample rate.
>
> To support a sample rate that is not in that list of predefined rates,
> your driver should set the RATE_KNOT bit and call the
> snd_pcm_hw_constraint_list() function; see the section "Constraints" in
> the "Writing an ALSA Driver" document.
>
>
> HTH
> Clemens
>