View source for Configuring Jack for use in Rivendell

['''NOTE: this page is woefully out of date. It's May 2020, and the current version of Rivendell is 3.4.0. Please don't use this guide for any recent versions of Rivendell.''']

From: Erik Anderson
Date: Tue, 19 May 2009 18:42:25 -0400

I am attempting to migrate my SUSE 10.2 Rivendell installation that is using a Delta 44 soundcard from ALSA to Jack. This is my first experience with Jack.  I have a few questions:

1. After reading the archives, I understand that the preferred method to auto-start jack is to use bash to set an environment variable of JACK_START_SERVER = 1, although the RD Jack.txt documentation mentions doing it the deprecated way. I assume the RD docs are outdated on this one, right?

2. I am a bit confused about the Rivendell audio resources and Jack. On this M-Audio, I have 4 ins and 4 outs. If I wanted to have 2 ins be mono and 2 as stereo, would one setup Jack to have 4 separate inputs like...

    Source1=alsa_pcm:capture_1
    Destination1=rivendell_1:record_0L
    Source2=alsa_pcm:capture_2
    Destination2=rivendell_1:record_0R
    Source3=alsa_pcm:capture_3
    Destination3=rivendell_1:record_1L
    Source4=alsa_pcm:capture_4
    Destination4=rivendell_1:record_1R

... and then setup the audio resource to be NORMAL, or would you somehow setup Jack to be 2 channels, and then use the LEFT or RIGHT in Rivendell Audio Ports to configure it? While on the subject, how does a Jack source relate to an audio port? Using ALSA, I just left everything as default (since it is not configurable) and found my ports by experimentation, but I think it is time for me to understand what is going on with the audio ports.


THANKS!!
Erik

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From: Dan Mills
Date: Wed, 20 May 2009 00:05:05 +0100


A rivendell port is always basically a stereo object, while a jack port
is a single channel, by default rivendell creates 8 stereo ports for
jack input and output.

So something like:

# Make jack inputs 1 and 2 appear as two mono inputs appearing on the
#left channel of rivendell ports 0 and 1 (set rivendell to record from
#left only) to make this work right). You could of course patch
#capture_1 to both record_L and record_R

    Source1=alsa_pcm:capture_1    
    Destination1=rivendell_1:record_0L
    Source2=alsa_pcm:capture_2
    Destination2=rivendell_1:record_1L
    # Source 3 and 4 are the first stereo pair.
    Source3=alsa_pcm:capture_3
    Destination3=rivendell_1:record_2L
    Source4=alsa_pcm:capture_4
    Destination4=rivendell_1:record_2R

qjackctl is a good tool for investigating what is going on with jack,
and the drag and drop patching is convenient.

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From: Erik Anderson

So, if I am following this right, I could then setup the inputs and outputs like:

    [JackSession]
    
    # This configuration will setup 2 stereo outputs on 1/2 and 3/4
    # and 2 mono inputs on 1, 2 and stereo input on 3/4
    
    #TREAT ALL OUTPUTS AS STEREO
    Source1=rivendell_1:playout_0L
    Destination1=alsa_pcm:playback_1
    Source2=rivendell_1:playout_0R
    Destination2=alsa_pcm:playback_2
    Source3=rivendell_1:playout_1L
    Destination3=alsa_pcm:playback_3
    Source4=rivendell_1:playout_1R
    Destination4=alsa_pcm:playback_4
    
    # SEND INPUT 1 TO RD PORT 0 LEFT AND RIGHT
    Source5=alsa_pcm:capture_1
    Destination5=rivendell_1:record_0L
    Source6=alsa_pcm:capture_1
    Destination6=rivendell_1:record_0R
    
    # SEND INPUT 2 TO RD PORT 1 LEFT AND RIGHT
    Source7=alsa_pcm:capture_2
    Destination7=rivendell_1:record_1L
    Source8=alsa_pcm:capture_2
    Destination8=rivendell_1:record_1R
    
    # SEND INPUT 3/4 TO RD PORT 2 STEREO
    Source9=alsa_pcm:capture_3
    Destination9=rivendell_1:record_2L
    Source10=alsa_pcm:capture_4
    Destination10=rivendell_1:record_2R

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You may also be interested in using [[jack-init]] - Phlash