[LAU] Jamulus private server [WAS]: Re: online calls with decent auido for music lessons

On 16/03/21 09:14, Lorenzo Sutton wrote: For anyone interested, it is a bit long, but hopefully interesting / useful for other :) For our first lesson yesterday we used Zoom for the sake of simplicity (especially for my teacher and to facilitate their schedule). Audio quality was decent on both ends), playing together was out of question (but expected with any similar platform due to latency). My teacher did point out that 'original audio' feature could improve audio quality even more... Unfortunately, as said, it doesn't seem to be available on Linux... Which is weird as you'd think that all of the funky 'noise reduction' / 'echo cancellation' stuff should be 'additions' and easy to 'turn off', not the reverse... I tried contacting Zoom but I assume they will never answer. In the meantime I did some tests (alone, using two laptops, see some specs at the end) with: - Discord [1]: sound quality was pretty good, especially after removing all of the noise reduction, and 'auto' features and lowering to the minimum 'voice activation' - and it does use Opus. It was not stereo (which for bass is ok, but would be nice to have e.g. if playing a backing track etc.). The nice thing was that video is included. I think that in order to have more fine-grained control over audio you need to download the client (so not using the web one), which does exist for Linux. Both parties need to have a registered account to use this, which might be a bit of a hassle for the other party who have to a) register and create yet another account b) install yet another application. Also log-in seems to require captcha and device verification (I guess due to abuse); but this makes the sign-up process and first star quite cumbersome. Audio is pulseaudio of course, which means pulseaudio sink for jack. A 'mobile App' exists. - Jami [2]: This is a P2P calling system and uses Opus. A bonus is that it supports Jack directly. It worked ok and included video, but I did notice a few dropouts and high CPU usage, and one end did crash at an instance. All in all, it didn't seem the quality was much higher than Discord. Also mono-only. But I think that's expected as this is probably and evolution of SIP 'softphone0' clients (e.g. like Egika?). Account creation is easy as you really just enter a name and username (no central email registration etc. needed). It does require both parties having an installed client. Again this last point might prove a bit of an additional hassle. A 'mobile App' exists. - Cleanfeed [3]: audio-only, web-only, freemium. Primarily aimed at online broadcasting / podcasting / news. Considering that this works out of the browser (Chrom* ones (including -ium) only officially supported but they try to make it work also on Firefox), I was quite impressed by the audio quality of the 'Music' setting available with the free account (they offer even higher bitrates with the paid ones. As a bonus 'music' is in stereo. I contacted support with a couple of questions and they were very friendly and helpful and seem also quite knowledgeable about Linux. The interesting feature here is that you just provide a link to the other party who join through a browser. This being browser-based also means you need pulseaudio and the sink if using jack (like in all my tests). No video means setting up some other (muted) video service for that. The browser-only link thing could make this relatively easy to propose by just sending the link to my teacher once we start the zoom call and having them use it for audio and mute their zoom, we shall see. They are also quite straightforward in saying that this is not primarily intended for online 'jamming'. - Jamulus [4]: audio-only, realtime online jamming-oriented with public 'servers', jack-native. This was actually real fun to test and play with. I tried some close-by servers and jammed a bit in the central one. With 128 frames set in JACK and using Jamulus' own direct monitoring latency was definitely acceptable and the audio quality pretty good. Audio-quality and music-friendliness wise this is probably the nicest to use. Only thing for a teaching setting is the public-only servers (the documentation mentions 'private' ones, but I haven't looked into if this is possible without actually 'hosting' a server), there is a workaround via soloing or muting others, but I don't think most teachers (nor students) would feel comfortable with anyone possibly coming in and listening to the lesson. Also video should be provided via some other tool and, of course, all parties need to have the software installed. That said this software is really well made and fun to use. (aside note there were a couple of 'troll' events in one of the public servers, and although they say don't feed the trolls 'audio trolling' can hurt your ears... Not sure how this could be solved, maybe some 'reputation' system like on Stack overflow or similar.. but that does have its flaws.. and it's another topic :-) In all tests my set-up was the following: Hardware: - Bass -> cheap Bass DI [balanced out] -> ZOOM H5 in | [H5 also providing microphone input via the included X/Y mics (so in 4-track mode] In all cases the Laptop I hooked the ZOOM H5 to was connected via network cable to the router. I'm also using (since about 1 week) an FTTH connection. With the exception of Jamulus, I also tried connecting the other test laptop via thetering 4G just to test what the other user would potentially hear, and the results were always pretty good (I did not however test the reverse). Software: - Jack - Zoom H5 shows 4 inputs in jack: the L/R mics and the inputs 1 and 2 - Where Jack was natively supported mic1+2 and input 3 were sent to the application -  Where Jack was not supported I added the pulseaudio sink (I always start that manually via a script I have since ages), with similar routing. - All of the software (with the exception of Cleanfeed which is web-based), I was able to find packaged for Manjaro either in the official repositories or in AUR. Things I'd like to try but din't have the chance to, yet: - SonoBus [5] - SoundJack [6] - JackTrip [7] [1]: https://discord.com/ [2]: https://jami.net/ [3]: https://cleanfeed.net/ [4]: https://jamulus.io/ [5]: https://sonobus.net/ [6]: https://www.soundjack.eu/ [7]: https://ccrma.stanford.edu/groups/soundwire/software/jacktrip/ _______________________________________________ Linux-audio-user mailing list Linux-audio-user(a)lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/linux-audio-user