[alsa-devel] ASOC PCM formats

Clemens Ladisch clemens at ladisch.de
Mon Jun 9 09:20:25 CEST 2008

Jon Smirl wrote:
> Why is the AC97 format set to S16 in all of the drivers? The link is
> 20b and my codec takes 20b, how do I get 20b data to the device?

You can only use sample formats that are supported by the AC97

> I tried using SNDRV_PCM_FORMAT_S20_3BE but all I get is static.

S20_3LE could in theory be used by USB devices.  There is no hardware
that supports S20_3BE.

How did you use this format?  Which driver is this?

> If I use S24 for the format it works but volume is divided by 16.

S24 means that the 24 sample bits are in the least significant bits of
a 32-bit memory word.  24 sample bits in the most significant bits of
a 32-bit memory word would be S32.  (It might be possible that your
driver gets this wrong.)


More information about the Alsa-devel mailing list