At Sat, 22 Dec 2012 01:43:13 +0100, Vincent Vinel wrote:
Hello,
The bugtracker seems to be down, so I'm posting here instead.
I was trying to use software mixing with my Native Instruments USB soundcard (snd-usb-caiaq), but all attemps to use the dmix pcm ended up with the rather unhelpful error : ALSA lib pcm_dmix.c:1311:(_snd_pcm_dmix_open) Unsupported format When using the hw pcm, however, aplay was kind enough to display the list of available formats, which in my case was limited to S24_3BE. A quick check confirmed that dmix doesn't support that format, which happens to be the only format available for NI USB soundcards (as defined in snd-usb-caiaq).
Is it worth writing a patch for 24bit big-endian support in dmix ?
If you find it's useful, it's worth, yes ;)
The patch won't be that big, it's just adding swapped version of generic_mix_areas_24() and generic_remix_areas_24().
External soundcards like these ones are usually used for realtime effects processing and low-latency audio, things for which dmix proably isn't suited anyway.
Takashi