Lmms: Better JACK support

[tresf]

This is a placeholder to consolidate JACK related issues and requests. If a new JACK bug is reported on the tracker, close it out and mark it as a duplicate of this bug, #1467

---

Enhancements:

• [ ] JACK support on Windows (#2136) and MacOS
• [ ] JACK transport support #523
• [ ] JACK MIDI support #2038
• [ ] JACK inputs (for recording, eventually) #908
• [ ] JACK outputs #908
• [ ] JACK sends #524
• [ ] JACK freewheeling #908
• [ ] JACK samplerate should be default for exports #2211
• [ ] Support Jack v1 and Jack v2 in our AppImages #3719
• [ ] Choosing how many outputs with JACK #5456

Bugs:

• [ ] JACK output/rendering issues #1162
• [ ] JACK reconnection issues #1240

Related:

• [ ] ALSA to JACK bridge distortion #276

[Umcaruje]

This should be turned into a task list so its easier to mark fixed issues.

[tresf]

This should be turned into a task list so its easier to mark fixed issues.

:)

[simonvanderveldt]

FYI Initial JACK midi support is in #2038

[unfa]

Does anyone know what is the status of JACK transport support?

It'd really kick ass to have this, even in a simplest form (like - no tempo changes supported).

[matt-bel]

I've checked out on this http://jackaudio.org/files/docs/html/transport-design.html#transportcontrol
seems to be possible implement that when the play and stop buttons are played...

[gi0e5b06]

@matt-bel https://github.com/gi0e5b06/lmms/commit/d8fb40cdb4943e4c0589281f8c3a4ad2f4a2dc0c
lmms as a client, basic transport.

[Umcaruje]

@gi0e5b06 here's how you make a Pull Request out of that commit:

First, you add an upstream remote (ignore if you did this)

$ git remote add upstream https://github.com/LMMS/lmms.git

You need to check out a new branch:

$ git checkout -b basicJackTransport

Next, we need to hard reset that branch to the current master:

$ git fetch upstream
$ git reset --hard upstream/master

Then you want to cherry pick your commit on the new branch:

$ git cherry-pick d8fb40cdb4943e4c0589281f8c3a4ad2f4a2dc0c

After that you can push your branch:

git push --set-upstream origin basicJackTransport

Then on the github UI on the website, when you go to https://github.com/LMMS/lmms, you'll see this:

Click the green button to make a pull request.

And boom, your change gets reviewed and can safely get tested and merged.

[matt-bel]

@gi0e5b06 i've tryed to compile with it but that patch is not working, are you planning to debug and
get it done out or just abandoned?

[gi0e5b06]

The first patch was adding the slave mode (qjackctl controlling lmms).
The new patch (WiP) https://github.com/gi0e5b06/lmms/commit/45ccdc9e5b73c5ba9d38ea5890907d4e862837b9 adds the client mode (making the play/stop buttons in lmms working again) and introduces the ITransport interface.
I'm planning to add full client mode, however it is a bigger task because of the actual bad design/spaghetti code.
I don't plan to add master mode soon.

[gi0e5b06]

@zonkmachine About the crash on exit (if you're using Jack), this is fixed by https://github.com/gi0e5b06/lmms/commit/b21a9cf3e03f49091cd064c6afde38708198f45f . Jack was still processing in the destructor.

@matt-bel About the sync: both Jack and LMMS being fully digital, they should stay synchronized (at the frame level). So that's something that can be fixed somehow. I put the transportQuery() call at the end of the processing. Let me know if it is better or worse.

[matt-bel]

@gi0e5b06 just tested it and tryed to sync with ardour metronome (only jack transport) + hydrogen kick and snare (ardour is perfectly in sync to hydro) with slave master and client option, still not perfectly in sync, there's like a some milliseconds delay, tested the other day (not this build but would be the same result) with jack transport + midi clock = https://www.youtube.com/watch?v=2PYt4hJUA9o, perfect because the midi delay control
maybe a regolable controller on the midi delay may help!?
transport not working if song editor loops are used in any case

[zonkmachine]

@gi0e5b06 Thanks! I've bumped #devtalk on Discord.

[ycollet]

I vote for this one. Required to allow lmms to control xjadeo

[zicklag]

Sorry for the ping if commenting like this is discouraged, but I would love to have Jack transport support. ( just tell me and I won't do it again ;) ) I sync up MuseScore with Ardour to add digital instruments to my recordings, but LMMS has a lot more features from an effects and automation standpoint so it would give me a lot more powers if I could sync LMMS with Ardour.

[trebmuh]

@tresf : what about adding #5456 in https://github.com/LMMS/lmms/issues/1467#issue-52483742?

[Spekular]

@trebmuh done!