[GnomeMeeting-devel-list] DMIX with GnomeMeeting

[Damien Sandras <dsandras seconix com>]

Hello,

A few of you have reported problems with DMIX and GnomeMeeting.

The symptoms are that when DMIX is used, the jitter buffer in
GnomeMeeting constantly increases due to the growing latency added by
DMIX.

That is due to full-duplex problems introduced by DMIX. However, there
is a way to prevent that: use the same period_* buffer_* parameters for
DSNOOP (capture) and DMIX (playback).

The file .asoundrc in attachment is an example of config that works.
The latency added by DMIX is about 80 to 100 ms. It could be better, but
it is still acceptable.

Enjoy!

PS: Yes, I'll add it to the 2.00 FAQ.
-- 
 _      Damien Sandras
(o-     
//\     GnomeMeeting: http://www.gnomemeeting.org/
v_/_    FOSDEM 2006 : http://www.fosdem.org
        SIP Phone   : sip:dsandras gnomemeeting net 
                      sip:600000 gnomemeeting net

# Useful so that all settings can be changed to a different card here.
pcm.snd_card {
	type hw
	card 0
}

# Allow mixing of multiple output streams to this device
pcm.dmixer {
	type dmix
	ipc_key 1024
	slave.pcm "snd_card"
	slave {
		period_time 0
		period_size 1024
		buffer_size 8192 
		rate 44100
	}

	bindings {
		0 0
		1 1
	}
}

# Allow reading from the default device.
# Also known as record or capture.
pcm.dsnooper {
	type dsnoop
	ipc_key 2048
	slave.pcm "snd_card"

	slave {
		period_time 0
		period_size 1024
		buffer_size 8192
		rate 44100
	}

	bindings {
		0 0
		1 1
	}
}

# This is what we want as our default device
pcm.duplex {
	type asym
	playback.pcm "dmixer"
	capture.pcm "dsnooper"
}


pcm.!default {
	type plug
	slave.pcm "duplex"
}