ubuntu: 2.01, 2.02 slow startup, jack problems

I’ve been a long time user of Audacity and have never had problems before. I have just install ubuntu studio 12.10 on a new computer, and have a new sound device (a Focusrite Scarlett 2i4). It works fine with linux and is a very nice device, however, Audacity doesn’t seem to be playing nice with it.

The first issue, which I think has been previously reported, is a very slow startup time… I get the following message:

ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Connection refused

ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Connection refused

ALSA lib pcm_dmix.c:957:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started

… then a very long wait (20 secs where nothing seems to be happening apart from the usb device being probed (flashing red lights… nasty clicks)).

followed by:

Expression ‘stream->playback.pcm’ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 4541
Expression ‘stream->playback.pcm’ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 4541
Expression ‘stream->playback.pcm’ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 4541
Expression ‘stream->playback.pcm’ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 4541

(by the way, this is with alsa running on its own, or with pulseaudio).

Once started, it kind of works, but whenever I want to play something, there is again a long pause (5 secs say) with clicking and flashing lights on the front of the usb device before playing commences.

So I have also tried it with jack. With this, it starts instantly, but no audacity input/output ports are visible in the qjackctl audio connection dialog, so basically useless.

Same with both 2.01 (which is the version shipped with ubunutu 10.10) and 2.02 (“raring”). Both are binaries. Not tried compiling from source yet. Never had to bother doing that before…

James

If it’s on, try turning Transport > Software Playthrough off in Audacity, and choose a project rate that the device supports.

When opening jackd and Audacity, the Audacity connections in qjackctl are not permanently available, only appearing when playback or recording is started, and disappearing when stopped.

The best way to connect to available JACK inputs and outputs is directly from Device Toolbar. Use Transport > Rescan Audio Devices when necessary, for example to make new applications ports available to Audacity.


Gale

Thanks! Using Alsa, adding Software Playthrough helps with getting rid of the device probing (and associated clicks) every time I press play, but startup is still very slow (30s compared to 1-2 seconds normally). I don’t understand why Audacity needs to probe the device every time it is started.

Jack actually works very well though - with fast startup and no pauses when playing. It was just confusing not to see the audacity ports available for connection when it started up.

James