Subject: aplay -Djack fails with "Sample rate non available"

From: Jonathan Nieder <[email-masked]>
Date: Mon, 11 Jan 2010 22:18:29 -0600

Package: alsa-utils
Version: 1.0.16-2

Hi,

Stock lenny system.  When jackd is running (with
“jackd -d alsa -d hw:0 -r 44100”), programs cannot talk to ALSA
(device or resource busy).  So I think, “maybe it will work if
ALSA uses jack as a backend”.  Luckily, libasound2-plugins
includes a file /usr/share/doc/libasound2-plugins/README-jack
explaining how to set this up.

Unfortunately, the instructions do not work: after setting up
asound.conf:

	$ aplay -Djack "Yardbirds - Birdland"
	Playing WAVE 'Yardbirds - Birdland.wav' : Signed 16 bit Little Endian, Rate 44100 H
	aplay: set_params:918: Sample format non available

and no sound is output.

Eventually, I did get alsa output through jack working, using
the instructions at <http://alsa.opensrc.org/index.php/Jack_(plugin)>.
Those indicate to use this configuration file:

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

	pcm.jack {
		type jack
		playback_ports {
			0 alsa_pcm:playback_1
			1 alsa_pcm:playback_2
		}
		capture_ports {
			0 alsa_pcm:capture_1
			1 alsa_pcm:capture_2
		}
	}

	ctl.mixer0 {
		type hw
		card 0
	}

The version in /usr/share/doc/libasound2-plugins/README-jack
is missing the pcm.!default and ct.mixer0 stanzas and misspells
capture_2 as pcapture_2.

With that expanded configuration file, most files play out of
the box, and for example, “aplay "Yardbirds - Birdland"” works.
But still “aplay -Djack "Yardbirds - Birdland"” still fails,
and with the same message.

Any ideas?

Thanks,
Jonathan

jackd is version 0.109.2.5