Raspberry Pi 2

Discussion of all things Raspberry Pi / Raspberry Pi 2 related

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Frank Carvalho
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Joined: Sat Nov 17, 2012 3:36 pm

Re: Raspberry Pi 2

Postby Frank Carvalho » Mon Dec 21, 2015 7:52 pm

I learn something all the time. http://wiki.linuxaudio.org/wiki/raspberrypi suggested the addition of autostatic repository which has updates of some antiquated versions of raspbian audio applications. And guitarix among them it seems! After executing these lines:

Code: Select all

wget -O - http://rpi.autostatic.com/autostatic.gpg.key| sudo apt-key add -
sudo wget -O /etc/apt/sources.list.d/autostatic-audio-raspbian.list http://rpi.autostatic.com/autostatic-audio-raspbian.list
sudo apt-get update
sudo apt-get install --reinstall guitarix

I am now running guitarix ver. 0.29! Nice! And so I can run guitarix headless with the -N option.

Now, I still have issues with latency....


Edit: With the stock raspbian kernel, and a startup script that I copied from the linuxaudio wiki, and added lines for killing lx desktop, starting jackd with realtime priority 70, guitarix start and webui start, I can get jackd down to around 10ms with block size 256. It plays reasonably and without errors over a long period of time (I played for two hours with no issues), but the latency can still be felt.
Block size 128 doesn't fare well. It plays, but has some horrible ring modulation-like noise sounding like the buffer cannot keep up with the audio stream. Does anyone believe that an rt-kernel will improve latency further? I just found a prepared image with a precompiled rt-kernel that I could try out.
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.

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Joined: Mon Apr 26, 2010 9:05 am

Re: Raspberry Pi 2

Postby madtom1999 » Sat Jan 23, 2016 5:12 pm

Just playing around with the Pi2 - I have a £5 'guitar' USB connector which provides me with 16 bit sound.
I've got the Calf Plugin Pack for Jack running OK though I cant get a2jmidid working - seems to just lock out the system,
Yoshimi seems to work OK.
I'm wondering if re-compiling things to take advantage of the 4 cores will help reduce latency problems.
I've run linux music stuff on less powerful machines quite successfully and, given the cost of the Pi2 I'd like to see if its possible to get it all working easily so a primary school kid can easily get it up and running.
Anyone interested in collaborating?

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