Hi David, thanks, your mail brought me to the right solution: The problem was that I had installed jack and should have had jack2 installed. It's really a pain with jack vs jack2 vs jack2-dbus. I would prefer to have either the version 1 jack lib removed altogether or at least get a warning when installing lmms and other pro audio apps that the wrong lib is installed. -- Orm Am Sonntag, den 13. Januar 2019 um 18:01:52 Uhr (+0100) schrieb David Runge:
Hi Orm!
On 2019-01-12 21:15:58 (+0100), Orm Finnendahl wrote:
I'm experiecing problems using lmms. I didn't use it before so it might be related to wrong settings.
1. lmms doesn't run with rt mode enabled in jack.
The terminal says:
"cannot lock down memory for RT thread (Nicht genügend Hauptspeicher verfügbar)" This is coming from the jackd log output or when starting lmms in a terminal? How are you starting jack currently?
When I start jackd, it gives me this:
``` Jan 13 17:45:47 dvzrv jackd[14075]: JACK server starting in realtime mode with priority 80 ```
When I start lmms in a terminal I only get some some VST sync support messages and some sample rate related ones, but none indicating the above problem.
This is strange as the computer has 20GB of Ram and only 2GB are used upon startup.
My /etc/security/limits.conf says:
@orm - memlock unlimited @orm - rtprio 99
lmms is running with the "orm" userid. My user is in the 'realtime' group, which takes care of rtprio/memlock now. I assume your user is also in the 'orm' group, yes? Can you check what `ulimit -a` gives you?
FWIW: The 'audio' group is largely irrelevant on Arch these days it seems (as access to audio devices is taken care of by udev).
2. Using a VST plugin (The Demo version of the Legend by Synapse) creates nasty audio dropouts when sending pitchbend or other continuous data while playing (with both, the ALSA or JACK non-rt output). The dropouts are clearly related to the incoming Midi (which is using the ALSA Sequencer interface). The cpu load is around 38% when playing and doesn't change if continous data is received. If it was hardware you'd suspect that midi in and audio are sharing the same interrupt...
I know this might be a problem of VST with wine in general or something related to the way the synth is programmed but with these clicks the plugin is basically unusable with controllers and maybe someone knows ways to circumvent this problem. The VST plugin seems to be executed by this process:
/usr/lib/lmms/RemoteVstPlugin.exe.so \ /tmp/{3e7dc1eb-ba62-4900-9b5f-ec04d555ec23} xembed I don't really use VSTs (nor wine for audio), so others might be of better help regarding this. That being said, there seem to be quite a few bugs in lmms regarding VST: https://github.com/LMMS/lmms/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+vst
Aside from that: I also get xruns on just adding instruments or LADSPA plugins in that application, etc. so I guess the host might be not too realtime safe. It's fairly possible, that you're encountering a bug in lmms.
Best, David