zrythm VS openAV-Ctlra

Zrythm is

I just tested Ubuntu 22.10+PipeWire+Zrythm and I get the exact same result. I have to run /usr/bin/pw-jack /opt/zrythm-1.0.0.beta.3.10.1/bin/zrythm_launch unless I install Zrythm from Flatpak as Flatpak seems to already embed pw-jack.

Free and opensource DAWs: Ardour is the "standard" traditional DAW, but I recommend checking out Zrythm or Qtractor as you might prefer their workflows.

we keep a fork there if you prefer to use github (https://github.com/zrythm/zrythm) but we don't actually use github for development

if you really want to use github pull requests instead of sending patches feel free to do that and I'll still look at them but we recommend patches via email because it's an open and standard system

Zrythm looks promising, though I'm not an audio guy, myself.

alias zrbuild=”startdir=$PWD ; mkdir binary ; git clone https://github.com/zrythm/zrythm.git ; cd zrythm ; meson build -Dprefix=$startdir/binary/ ; meson compile -C build ; meson install -C build”

I have been talking to the author of Ctlra who has reverse engineered the screens. The screens work by sending a bunch of pixels to a vendor defined class USB bulk endpoint. Unlike some other controllers with screens which just take some metadata from the software and do their own rendering, Native Instruments controllers with screen rely on the software to do the rendering. Traktor does this by rendering QML to an offscreen buffer. However, according to the author of Ctlra it is more complicated than that to get 60 FPS framerate to the screens because simply sending all the pixels continuously saturates the USB bus. Fortunately that doesn't interfere with any other features of the controller because the other USB signals have higher priority (isochronous for the audio, interrupt for the HID). So to get a good framerate, which would matter for sending scrolling waveforms to the screens, my understanding is that Mixxx would have to compare every rendered frame to identify which rectangles of the screen to update in each USB packet.