[LAU] Streaming setup with OBS and JACK

[Jacek Konieczny]

Hi,

On 2018-07-25 08:56, hollundertee at gmx.net wrote:
> Overview
> I have been live streaming on twitch for the past year, mostly games
> and purely as a hobby. The possibilities of PA and OBS for routing and
> audio processing are rather limited, I'd like to try and improve my
> setup by adding JACK to the mix.

I have never done any live streaming, but I have used OBS with Jack and
Pulseaudio to record my Yousician session.

> Current Setup
> 2-3 Audio interfaces.

Jack works best with only one interface, but there are ways around it.


> 1) Can someone tell me whether the OBS jack plugin is good enough or
> does something stupid? The code can be found here:
> https://github.com/obsproject/obs-studio/tree/master/plugins/linux-jack

I had the Jack support included in my OBS build. Works quite well. In
fact much better than e.g. Jack support in audacity which I found unusable.

> 2) Is there a reliable and if possible hassle free way to get ALSA and
> PA into JACK? ALSA loopback would probably not work for programs using
> PA directly.

I used Linux version of Yousician (when it was still a thing) and it had
ALSA output only. That was going into PulseAudio via the pulsaudio alsa
plugin. PulseAudio routed it to its Jack sink, which I have connected to
OBS. My guitar signal would come from an USB audio interface, via
Guitarix as another input to OBS. Sometimes I would also connect the
clean signal directly to OBS.

For me the only limitation was the limited performance of my laptop – a
bit too much going on and I would get xruns in jack, corrupting the
audio. Note: I use real-time kernel to keep latency low, which might be
quite important for monitoring.

> 3) I think switching around monitoring should be doable with a simple
> script calling jack_connect, provided the ports are predictably named.
> Even I should be able to do that. Is there another solution?

You could use some audio plugins in Carla and control them via OSC or
MIDI, if you have any MIDI controller (a MIDI keyboard, a foot switch or
even a phone app).

> 4) Even though it's a small setup I'd need some sort of session
> management to bring up at least the jack side of things.

I would just load a patchbay with all the needed connections and plugins
in Carla.

> 5) Finally what do you recommend as plugin host and compressor plugin
> for voice?

Carla as host, I am not familiar with compressor plugins.

Jacek