fixing output to jack-rack when jack-rack PIDF has changed

[richard-g8jvm2]

Hi
Is there any way of getting around audacity starting up with Jack connections always defaulting to
the system playback ports.
I'm using jack-rack and I need to route playback through it,
I'm aware that each time jack-rack is started the PID will change, so saving the current config in edit>preferences>.devices
will be wrong as the PIDs will not match.

in audacity.cfg
[MP3]
MP3LibPath=/usr/lib64/libmp3lame.so.0
[AudioIO]
RecordingDevice=JACK Audio Connection Kit: jack_rack_13178
Host=JACK Audio Connection Kit
PlaybackDevice=JACK Audio Connection Kit: jack_rack_13178
RecordChannels=2
EffectsPreviewLen=3
CutPreviewBeforeLen=1
CutPreviewAfterLen=1
SeekShortPeriod=1


could SED or something similar be used to write the correct PID for jack-rack
as I know what the PID is before audacity is started ?

something like:-
/bin/sed -ie PlaybackDevice=JACK AUDIO Connection Kit:jack_rack_"$JACKR_PID <location of audacity.cfg>


TIA

Richard

[steve]

You've posted in the Audacity 1.2.x part of the forum, but I bet you're using a 1.3.x version of Audacity.
Look in the Audacity "Help menu > About Audacity" for the exact version number.

The latest (1.3.13) version of Audacity has improved connection control when used with Jack. The "Device Toolbar" is enabled by default, and the Audacity input/output ports can be connected to any available output/input ports that Audacity knows about, from the Device Toolbar.

For Audacity to know about available ports in other Jack applications, those applications must be opened before you start Audacity. So the correct order of opening things to use Audacity with jack is:
1) Start Jack
2) Open all other Jack enabled applications that you may want to connect to Audacity
3) Open Audacity.

If you are using an earlier version of Audacity 1.3.x, you can set up Jack Patchbay to work with Audacity as described here: http://forum.audacityteam.org/viewtopic ... 18&t=29963

[richard-g8jvm2]

SRi , it should have been in 1.3.xx

I've read through that link, and unfortunately it doesn't go far enough.

I'm writing a script to start audacity after starting jackd and jack-rack.
I'm OK with getting all the routing from jack-rack to jack, and getting the jack-rack auto configured.
BUT I'm stuck with getting audacity to see the jack-rack input.
I can do it manually BUT and its a big but.
I will be using this in court in an action against my employer, and I don't have legal aid, so what I'm trying to do is get everything configured from one script.
So all I need to do is click on the play icon.
If I have to start fumbling around, when getting cross examined by a professional, things will go wrong.
I'm getting pretty apprehensive now, by the 27th of this month, I'll be a lot worse.

I'm close with the SED line
/bin/sed -ie "PlaybackDevice=JACK AUDIO Connection Kit:jack_rack_"$JACKR_PID <location of audacity.cfg>
but its complaining of extra characters
so its finding a method of writing to the config file.

I hope the explanation makes sense.

thanks

[steve]

Topic moved.

Are you running Jack Control?

[richard-g8jvm2]

Yes I'm running qjackctl, but I'm setting up the links with a script, that is working, so the connection from jack-rack to the system playback is OK.
I've tried the sed line after starting audacity, and I can see an extra port appearing on the playback side, then disappears.

Am I trying to write to the correct config file ? audacity.cfg.
Is that the file the initial config is read from on startup ?

thanks Richard

[steve]

OK, I see the problem. Jack Patchbay can be set to route Jack-Rack, using a regex

Code: Select all

jack_rack_[0-9]+

but Audacity ignores that and tries to use the specific instance of Jack-Rack that it used last, but when that's not found (because the PIDF has changes), it falls back on "system".

So you're wanting to access the audacity.cfg file after launching Jack-rack but before launching Audacity to change:

Code: Select all

[AudioIO]
RecordingDevice=jack_rack_xxxxx

to whatever the current PID is for Jack-Rack.

Does that summarise the problem?
If so, I think the solution will be to launch Jack-Rack with

Code: Select all

jack-rack -n

This launches Jack-Rack without the PID, so Audacity will just see it as "jack_rack" and having this in the audacity.cfg file should then work (assuming that you want Audacity to take its input from Jack-rack)

Code: Select all

[AudioIO]
RecordingDevice=jack_rack

[richard-g8jvm2]

Hi

yes that works beautifully
its the output from audacity that goes to jack-rack, where I use filters and some gain to get the audio so it can be understood.
digital audio recorders don't produce good quality sound when used in your pocket.

I suspect audacity has a few features I can use to help with that as well.

thanks for the help

Richard