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Re: Guitarix on a Raspberry Pi 2

Posted: Sun Apr 09, 2017 9:14 am
by Frank Carvalho
Yes, that solved it! Thanks. Now everything behaves the way its suppose to. I'm not sure I understand why, but it works!

/Frank

Re: Guitarix on a Raspberry Pi 2

Posted: Sun Apr 09, 2017 9:24 am
by tramp
Guitarix cache plugin data for performance reason and to allow the reorder of controls.
When a plugin change it's behave, those stored values may lead to such issues.
It may be that I've change the switch direction in one of the last commits.
When I remember right, the direction was wrong before, for using the default MOD switches.

Re: Guitarix on a Raspberry Pi 2

Posted: Sat May 20, 2017 12:57 am
by Fuylo
Like to start off by saying thank you for all the work y'all have done on this!

I'm riding passenger omw to a concert, SSH'd into my pi 3 model b at home from my iPhone, and successfully got through make install, after installing dependencies and building.

I read the rest of the post, but is there a summary bullet list from this post that someone with a good install on a ras pi 3 could point out? I'm on regular old rasbian.

I'm seeing that there was an issue with 48k, and some issues with realtime settings.

Do I need to set up the kernel to be realtime or am I gonna need to start over with a raspi pi with an os that's already RT?

Was the 48k thing fixed or is it a hardware limitation of the pi 3?

I'm gonna wait till I'm home and I can plug in my stenburg UR22 to it to keep going forward, but if there's a "best next-step to start on after install" let me know. Again, thanks for the work, and if I don't get a reply I'll make a step by step guide out of what I'll do to get it working from info from this thread and post it here!

Re: Guitarix on a Raspberry Pi 2

Posted: Fri Sep 15, 2017 3:14 pm
by maoz
Hi all,

I'm having problem building Guitarix on a Raspberry Pi Zero W.

I'm just want only to obtain the .lv2 plugins, so I've configured in this way:
./waf configure --lv2-only --lv2dir=usr/local/lib/lv2 --no-avahi --no-bluez --no-ladspa --no-new-ladspa --shared-lib --optimization --download --no-lv2-gui --no-faust

but when I try to build, it failed with this error:
./waf build
Waf: Entering directory `/home/pi/guitarix-git/trunk/build'
Waf: Leaving directory `/home/pi/guitarix-git/trunk/build'
object 'gxwmm' was not found in uselib_local (required by 'gxtape_gui')

I don't know how to do... Have you any ideas??

thanks in advance,

Maoz

Re: Guitarix on a Raspberry Pi 2

Posted: Sat Sep 16, 2017 4:21 am
by tramp
fixed in guitarix git now.

Re: Guitarix on a Raspberry Pi 2

Posted: Sat Oct 21, 2017 3:38 pm
by Bullet0070
Hi all! Im very, VERY new to raspberry stuff. I want to do the IR loader using Raspberry Pi(which version is better?) + Guitarix. Ive never used Linux before and i absolutely dont know how to start. I think its not that hard considering that i only need an IR loader from guitarix? The result im looking for is small (kinda) pedal, like Pangaea CP-100 but with less fuctionality. And what audio interface will do the work? I mean small size. Something like Behringer UCA-222?

Re: Guitarix on a Raspberry Pi 2

Posted: Sat Nov 11, 2017 3:00 pm
by bassmannate
Trying to do the same on an rpi2 with the latest raspbian. It would but I get a very digital/8-bit sounding distortion after a few minutes of playing. It goes away and comes back if I wait long enough but it will also go away if I restart Jack.

I see most of the experimentation has been done on earlier versions of raspbian. As I'm running stretch, should I try to find Jessie and try on that instead? I've followed the instructions on the Linux audio wiki and an running headless to free up resources but no dice.

So close! If I can figure out this problem, I'm set!

Re: Guitarix on a Raspberry Pi 2

Posted: Sat Dec 30, 2017 12:13 am
by ParadoxGuitarist
bassmannate wrote:Trying to do the same on an rpi2 with the latest raspbian. It would but I get a very digital/8-bit sounding distortion after a few minutes of playing. It goes away and comes back if I wait long enough but it will also go away if I restart Jack.


Sounds like xruns, but it could be other things. Did you try increasing the buffer size to see if it goes away or happens less frequently?

Re: Guitarix on a Raspberry Pi 2

Posted: Sat Dec 30, 2017 12:19 am
by ParadoxGuitarist
Bullet0070 wrote:I mean small size. Something like Behringer UCA-222?

I had bad luck with Behringer. Be sure the device is supported by them in Linux. I had a 222 that worked fine, until the firmware got updated then it bricked it on the system unless I reinstalled. Behringer said they don't support Linux on the device, so use caution. Lexicon has some cheap/small devices that are supported. For a little more, so does Focusrite Scarlett has support for Linux.

Re: Guitarix on a Raspberry Pi 2

Posted: Mon May 14, 2018 9:19 pm
by Frank Carvalho
Frank Carvalho wrote:It's possible. I always run 48kHz on my main machine, and never had any problems with Guitarix or any other sound software. I also run the sound card at 48kHz on a laptop I have, so the sound card should be allright too. So the issues must arise from the RPi itself and the software running on it, though I can not get any closer.

/Frank


Just had to share this with you. I previously had a problem with Guitarix and the RPi giving a bad ring modulated kind of sound when run at 48kHz. Now I've recompiled the plugins, after Hermann added the internal resampling, and this seems to have solved my original problem, as now it plays nicely at 48kHz. I can't say how happy I am about this! As I experiment with the RPi as a frontend for a real amp, higher resolution sampling really makes a big difference in sound quality - and lowers latency too. Can't wait to put the recompiled RPi plugins in front of the amp again.

/Frank

Re: Guitarix on a Raspberry Pi 2

Posted: Wed May 16, 2018 7:20 am
by gimmeapill
Nice, thanks for updating on your progress.
Since this thread is getting pretty long, could you also summarize what s currently the "state of the art" when it comes to latency and audio interface?

Cheers,

LX

Re: Guitarix on a Raspberry Pi 2

Posted: Thu May 17, 2018 9:21 pm
by Frank Carvalho
I can try to describe my setup so far.
This Pi is version 2B with the official touch screen. Any newer version of the Pi will only make performance better.
I have installed a Raspbian image with RT preconfigured. It's a build called Emlid, made for use in drones, but works nicely for audio as well:
https://emlid.com/raspberry-pi-real-time-kernel/
After Hermann modified his makefiles, and his use of some libraries, the Guitarix modules compile and run perfectly on the Pi.
I use an M-Audio Quattro USB interface. The interface should be able to go all the way up to 96kHz, but I haven't tested 96kHz. I run jackd at 48kHz, using a buffer size of 64 samples, and a period setting of 4. Real-time is on, as is No Memory lock and - important - Soft Mode.
I found that 3 periods made the handling of the USB interface and buffers unstable. At 4 it is very stable.
This gives a JACK reported latency of 1.3ms.
Guitarix then attaches to jackd, also reporting buffer size 64. The delay from string to sound is close to unnoticeable. It doesn't feel delayed when you play, but if you turn down the amp volume, you ears can still register the very short delay between string and amplified sound.

There is probably a lot of details I forget here.

Another plan for the future is to get something like this:
https://www.indiegogo.com/projects/pisound-audio-midi-interface-for-raspberry-pi/#/
to get a compact, all-in-one solution - and perhaps get my son-in-law to 3D-print a matching cabinet.

/Frank

Re: Guitarix on a Raspberry Pi 2

Posted: Thu May 24, 2018 8:13 am
by gimmeapill
Thanks for the details, that is very helpful.

I'm planning something relatively similar: I can hardly approach my music computer those days, & I really need something not only portable but also fully battery powered, preferably in micro-combo format (quite a stretch, I know).

The path of least resistance to get there is probably be some kind of poor man's THR10x (at the moment I'm using just a Vox Amplug into a bluetooth speaker), but I really miss my Guitarix presets and chunky metal tone, so I'll probably walk down your traces at some point ;-)

Looking at the details of your config, that RT kernel doesn't look too fresh, the last update is from ~2014, did you have a look at this project?
https://github.com/guysoft/RealtimePi

They have a 4.14 RT kernel and it's used apparently by Zynthian.
So this could be a good base for an easily maintainable config...at least on the paper...

I use an M-Audio Quattro USB interface. The interface should be able to go all the way up to 96kHz, but I haven't tested 96kHz. I run jackd at 48kHz, using a buffer size of 64 samples, and a period setting of 4. Real-time is on, as is No Memory lock and - important - Soft Mode.
I found that 3 periods made the handling of the USB interface and buffers unstable. At 4 it is very stable.
This gives a JACK reported latency of 1.3ms.
Guitarix then attaches to jackd, also reporting buffer size 64.


As I understand that should bring you around 12-15ms roundtrip latency - that's ok'ish for a start but still a bit laggy to my taste.
could you measure the exact roundtrip latency with jack_iodelay ? That will also tell you how much you particular sound card is adding...
there's a howto there: https://www.linuxmusicians.com/viewtopic.php?t=8022

Re: Guitarix on a Raspberry Pi 2

Posted: Thu May 24, 2018 8:42 pm
by Frank Carvalho
Yes, it reports a total latency of 16 ms.

Re: Guitarix on a Raspberry Pi 2

Posted: Thu May 31, 2018 12:13 pm
by gimmeapill
Checking that Pisound project that you mentioned, and the form factor is indeed very nice.
Those two knobs would probably be enough for bread and butter operation of Guitarix.

They have also a "poor man's MOD" pre-built ISO:
https://blokas.io/pisound/docs/MODEP/
https://community.blokas.io/t/release-modep-2018-04-03/496

The latencies mentioned in the comments of the download page don't seem to be anything miraculous though, we're still in the 15-20ms ballpark...