Topic: Problem running pteq on Rasp Pi over ssh with X11 forwarding

Last year I installed Pianoteq on a Raspberry Pi 4 running the 64-bit Raspberry Pi OS 'lite' (just CLI, no GUI). I was able to start it by connecting to the Pi from an Ubuntu workstation over ssh with X11 forwarding.

I've just tried again on a new installation - latest version of the RP OS and Pianoteq - but this time I got this: error while loading shared libraries: libGL.so.1: cannot open shared object file: No such file or directory. I managed to fix this by installing the libgl1 package and now I get a Pianoteq window on my workstation but I can't interact with it - mouse and keyboard have no effect.

X11 forwarding is working in general - I can run other GUI programs on the Pi and interact with them on my workstation, but not Pianoteq.

Anyone got any ideas?

Thanks, Ian.

N1X - PT Pro - Linux

Re: Problem running pteq on Rasp Pi over ssh with X11 forwarding

IanL wrote:

Last year I installed Pianoteq on a Raspberry Pi 4 running the 64-bit Raspberry Pi OS 'lite' (just CLI, no GUI). I was able to start it by connecting to the Pi from an Ubuntu workstation over ssh with X11 forwarding.

I've just tried again on a new installation - latest version of the RP OS and Pianoteq - but this time I got this: error while loading shared libraries: libGL.so.1: cannot open shared object file: No such file or directory. I managed to fix this by installing the libgl1 package and now I get a Pianoteq window on my workstation but I can't interact with it - mouse and keyboard have no effect.

X11 forwarding is working in general - I can run other GUI programs on the Pi and interact with them on my workstation, but not Pianoteq.

Anyone got any ideas?

Thanks, Ian.

For Pianoteq to work correctly, you need X11 to be correctly installed. In particular, Pianoteq needs

* libX11
* libXau
* libXdmcp

Also, very sadly, all music related programs follow the very unfortunate idea started by that pile of <censored> that is called kontakt of not using standard GUI but custom images and custom interations. As such, a test with other X11 programs is only going to help debugging your setup marginally, but I digress...

Given the minimal install without X11, I am sure your OS install is missing some obscure X11 parts to save space and hence Pianoteq malfunctions. I suggest that you start making sure the above three packages are included in your install. Note that in most Debian/Ubuntu distros you will be encounter this problem complicating your sleuthing: https://askubuntu.com/questions/481/how...des-a-file

Alternatively you can control it via a webapp such as https://github.com/robert-rc2i/ptq-client-webapp

Hope this helps

Last edited by dv (20-09-2024 00:54)
Where do I find a list of all posts I upvoted? :(

Re: Problem running pteq on Rasp Pi over ssh with X11 forwarding

Hi dv,

Many thanks for getting back. I checked those three packages and they are already installed (latest version) on the RP OS lite build (basically Debian 12).

I'm not a fan of the PT GUI, for various reasons, but when I've tried to suggest there are problems with it before (in this forum) I've been shot down by the faithful. Dissent not welcome then. Oh well.

My approach is to use a GUI of my own design, fire up a PT instance and communicate with it using its JSON RPC server facility (as the webapp you link to does). But I run my GUI locally on the RP using DRI and a touchscreen. This works fine but it's nice to be able to fire up the 'official' GUI from time to time (during development) to check on various parameters, rather than just trying to tweak the config file manually, not least because I can't find any documentation on this file. As I say, this used to work fine, but doesn't any more. It's a shame that a standard Linux facility seems to be broken with this particular binary.

Best, Ian.

N1X - PT Pro - Linux

Re: Problem running pteq on Rasp Pi over ssh with X11 forwarding

Just in case it's of any interest to anyone I'm now working round this problem by installing the full (GUI) RP OS and enabling VNC. Then I switch it to boot just into the CLI (ie not load the GUI) and use PT headless, as I normally do. Far as I can see this avoids all the overhead associated with the GUI - runs just as lean and mean as before. If at any stage I want to check anything against the official PT GUI I just switch the Pi to boot into its GUI version, VNC onto it from my workstation and fire up PT this time without the 'headless' argument. Once checks done I revert to the CLI boot. This seems to cover all bases for me. I.

N1X - PT Pro - Linux

Re: Problem running pteq on Rasp Pi over ssh with X11 forwarding

IanL wrote:

If at any stage I want to check anything against the official PT GUI I just switch the Pi to boot into its GUI version, VNC onto it from my workstation and fire up PT this time without the 'headless' argument. Once checks done I revert to the CLI boot. This seems to cover all bases for me. I.

So if you stay CLI and try to open Pianoteq you reproduce the same problem? If so, then it's not as I speculated a missing library, but a runtime configuration instead. It would be very good to know which one is the case.

Thanks

Where do I find a list of all posts I upvoted? :(

Re: Problem running pteq on Rasp Pi over ssh with X11 forwarding

Yeah, X11 forwarding still kiboshed. Unsurprisingly, I don't see the initial missing libGL error, but the PT GUI over ssh is a joke - some sign of response at least some of the time to eg a mouse click, if you're prepared to wait about a minute for it. I don't know which end - whether my Ubuntu workstation or the RPOS on the Pi - is causing the problem. One interesting thing I noticed is that switching on VNC server on the Pi no longer switches the window manager from Wayland to <the other one> (can't remember what it's called - openBox?). Even just a couple of months ago that switch was still happening. So there's been tinkering going on behind the scenes. I suppose that finally X will be extinguished and, with it, the ability to forward graphics over ssh. Far as I know Wayland doesn't dirty its hands with that sort of thing and never will - possibly for security reasons. Shame. The bad guys always muck everything up for the rest of us. I.

N1X - PT Pro - Linux