Running SC 3.8.0 on linux fedora, (planet ccrma). I’m having trouble understanding how Jack and SC work together. Yesterday I tried to run SC with an external USB audio interface. And now I’m having trouble just booting the server with any audio interface (even internal) without some addtional jack tweaking.
Here’s the message I boot SC, after a machine boot (I have nothing in my startup.scd file):
booting 57110 jackdmp 1.9.12 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2016 Grame. Copyright 2016-2017 Filipe Coelho. jackdmp comes with ABSOLUTELY NO WARRANTY This is free software, and you are welcome to redistribute it under certain conditions; see the file COPYING for details JACK server starting in realtime mode with priority 20 self-connect-mode is "Don't restrict self connect requests" audio_reservation_init Acquire audio card Audio0 creating alsa driver ... hw:PCH|hw:PCH|32|2|44100|0|0|nomon|swmeter|-|32bit configuring for 44100Hz, period = 32 frames (0.7 ms), buffer = 2 periods ALSA: final selected sample format for capture: 32bit integer little-endian ALSA: use 2 periods for capture ALSA: final selected sample format for playback: 32bit integer little-endian ALSA: use 2 periods for playback JackDriver: client name is 'SuperCollider' SC_AudioDriver: sample rate = 44100.000000, driver's block size = 32 JackDriver: couldn't activate jack client start audio failed. RESULT = 0 ERROR: server failed to start For advice: [http://supercollider.github.io/tutorials/server-failed-to-start]
After some googling around, I found that I could fix it with this command in a terminal:
jackd -d alsa -d hw:PCH
Now when I boot the server in SC, it works OK:
booting 57110 JackDriver: client name is 'SuperCollider' SC_AudioDriver: sample rate = 48000.000000, driver's block size = 1024 JackDriver: connected system:capture_1 to SuperCollider:in_1 JackDriver: connected system:capture_2 to SuperCollider:in_2 JackDriver: connected SuperCollider:out_1 to system:playback_1 JackDriver: connected SuperCollider:out_2 to system:playback_2 SuperCollider 3 server ready. JackDriver: max output latency 42.7 ms Receiving notification messages from server localhost Shared memory server interface initialized JackDriver: killed by jack RESULT = 0
Now the audio works with my internal audio interface. But I have no idea why this works, what’s happening between jack and SC, why I need this command… I’m pretty confused, and I would need to understand what’s happening so that I can confidently switch between several audio interfaces.
Can somebody help me understand what’s going on?
Thank you very much.