[Alsa-user] Fine tune an untunable plugin (or "usb_stream gets a period_size")

[<mi...@ca...>]

  Hi there, world!

  I'm having trouble configuring a new PCM device.  Here's the setup:  I
have a usb_stream device (card 1), configured as :

pcm.!usb_stream {
	type usb_stream
	card 1
}

It works great with, say, jack, or when I fine tune the playing, i.e. :

$ aplay /dev/urandom -D usb_stream -r 44100 \
                      --period-size 128 --buffer-size 256

but some software (e.g. Audacity) doesn't offer the ability to tweak the
period and buffer sizes.

The usb_stream plugin doesn't seem to support any other directive than
`card' (according to the source code), so I checked other plugins for a
better support.  I can indeed tweak the rate with a `plug' plugin, but I
couldn't find any way to do the same with the two other crucial
parameters.

I've always felt loss with Asoundrc editing, so I may be out of the way,
but can you guys help with that?

Thank you!

-- 
Michaël `Micha' Cadilhac (LITQ, U. de Montréal) -- http://michael.cadilhac.name
	||   A typical Free Software project is not a democracy;
	||     It's more like a voluntary monarchy.
	||        -- A wise person