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Re:Zoom improvements requested by music schools by nullc on Thursday January 14, 2021 @06:26PM (#25784525)
> Latency will always be an issue here.

No, it will not. :) You can get to 5ms above the network delay, even using compressed audio (opus), though some sound devices may be picky.

Network delay can be just a few milliseconds even across a city, assuming that no latency murdering devices (wifi or nics in interrupt mitigation mode) are on the path.

This means that you can have lower audio delay from a compressed audio conference crossing your state than is achieved from speed-of-sound delays from a performer sitting on the other side of a moderate sized room!

The future is already here -- it's just not very evenly distributed. (yet)

Re:Zoom improvements requested by music schools by PaulDavisThe1st on Thursday January 14, 2021 @06:29PM (#25784577)
> Network delay can be just a few milliseconds even across a city

If you limit your collaboration radius in that way, then sure (though it still depends on the router technology the packets encounter along the way). But if you want to go beyond that, the numbers get bigger. For transcontinental stuff, much much longer.

But thanks for correcting the basic thrust.

Re:Zoom improvements requested by music schools by nullc on Thursday January 14, 2021 @07:04PM (#25784957)
One way delay between San Francisco and New York city is 37ms across the public internet today.

This is the same one way delay as sound in air across 12 meters, which would be on the large size for an orchestra pit.

It does get larger as you go further, but live performance with people on the other side of a large continent is completely realistic and has been done. :)

Sure, expecting to go between NYC and someone in china behind the GFW is probably asking too much for a seamless experience. But many people mostly want to work with people in the same country as them ... and for that, with sufficient technology, latency need not be an issue.

Re:Zoom improvements requested by music schools by PaulDavisThe1st on Thursday January 14, 2021 @07:31PM (#25785240)
> live performance with people on the other side of a large continent is completely realistic and has been done. :)

In case you're not aware, I'm the original author of JACK, around which JackTrip is built, which is the most likely and reliable tool for such a collaboration. I certainly know people who've done this, and I regret that I didn't realize back in February how useful it would have been to make something like JackTrip into a much easier-to-use tool for computer-naive folks.

37ms cross-country in the USA is optimistic, but certainly possible. US->Europe is not so great.

Re:Zoom improvements requested by music schools by nullc on Thursday January 14, 2021 @07:59PM (#25785509)
In case you're not aware, I'm one of the authors of Opus. :P

When the pandemic hit I thought about putting out some pointers to easier to use low latency streaming resources... but... that would require overcoming pandemic lockdown funk. And honestly it's still kind of a technical rats nest to get everything working. It's not exactly musician friendly to need instructions like "next you need to make sure your nic doesn't enable interrupt mitigation when there are more than 100 packets per second...". :)

[I love Jack BTW.]

Re:Zoom improvements requested by music schools by raphlinus on Thursday January 14, 2021 @08:07PM (#25785581)
Another example of HN being amazing. In the interest of playing too, I did some work on reducing audio latency in Android, but that all predated AAudio/Oboe, which takes that quite a bit further and makes at least the Pixel devices a plausible platform for low-latency audio collaboration apps as suggested in this thread. I for one would love to see that happen - I miss singing hymns on Sunday mornings.
Re:Zoom improvements requested by music schools by PaulDavisThe1st on Thursday January 14, 2021 @09:12PM (#25786104)
Yeah, I'm really sad that I didn't get some serious effort together on this back at the start of the year. There's no lockdown funk here, just too busy working on Ardour.

One of the 2 netjack implementations uses Opus - great stuff.

Absolutely right that the good stuff (i.e. not zoom) requires way too much setup, and even then (as you note) you're not guaranteed reliable function because you don't control all the hops. Soundjack gets the user-side fairly good, but it's still not quite what I think would have really taken off during the pandemic - probably needs a mobile app for that.

Re:Zoom improvements requested by music schools by spacechild1 on Friday January 15, 2021 @12:17AM (#25787272)
I love libopus! I use it as one of the codecs for my low latency streaming library “AOO“ https://git.iem.at/cm/aoo
Re:Zoom improvements requested by music schools by sonosaurus on Sunday January 17, 2021 @02:08AM (#25808822)
And I love AOO, I use it as the basis for SonoBus.... I’ve been meaning to contact you about it, and work on merging your latest into my fork (which has diverged a bit over the last few months).

And hey Paul, long time no chat!

https://sonobus.net

Re:Zoom improvements requested by music schools by gabereiser on Thursday January 14, 2021 @07:37PM (#25785294)
Thank you for JACK btw.
Re:Zoom improvements requested by music schools by gabereiser on Thursday January 14, 2021 @07:35PM (#25785277)
Latency in this case is cumulative. 1-5ms for DAW encoding of your analog signal, encoding it in whatever codec is used for transmission 1-?ms. Actual transmission 10-1000ms. Decoding the signal into audio channels for playback 1-5ms. Don’t forget this is duplex. You are transmitting as you are also receiving. In an ideal world we could get very close to zero-latency (enough where an orchestra could by in time step with each other).

It sounds do-able. It sounds like we should already be there. Looking around though you’ll see we aren’t because of technical issues described that are systemic of the infrastructure used.

Re:Zoom improvements requested by music schools by PaulDavisThe1st on Thursday January 14, 2021 @09:13PM (#25786117)
JackTrip doesn't encode at all, it sends raw PCM over the wire. So that helps.
Re:Zoom improvements requested by music schools by LeifCarrotson on Thursday January 14, 2021 @07:30PM (#25785232)
Network delay can be just a few milliseconds across a city, or you can discover, like my brother who teaches elementary music, that your kids have different ISPs and some are awful.

He's been teaching music remotely since August, and one of the first days he demonstrated why they have to be on mute on Zoom by having them all sing happy birthday to one of the students. It was utter chaos. I worked with him to try to find a solution, we tried various tools, but found nothing that worked across cable, DSL, WISP, and cellular connections.

Some tools could sync after the fact so the recording sounded good (if each musician keeps the same tempo), but the whole point is that the kids needed to be able to hear and follow each other, and just one student at 500ms latency totally ruins the tech.

So he teaches music to second graders by zoom, and they're all on mute unless he unmutes them one by one.

Re:Zoom improvements requested by music schools by telesilla on Thursday January 14, 2021 @06:41PM (#25784699)
> Latency will always be an issue here

Yes, it will as soon as you are 1000km away. Light speed creates a lot of unresolvable latency. How can you play live between London and Sydney? You need a different musical understanding.

Re:Zoom improvements requested by music schools by Retric on Thursday January 14, 2021 @06:52PM (#25784827)
1000km at the speed of light is 3.33 ms which on it’s own isn’t an issue. While fiber is slower, you can have low latency connections over that distance without issue.

The real problem is computer audio isn’t designed for low latency. Generally, as long as video and audio are reasonably synchronized nobody notices, but latency as rarely a consideration on it’s own.

Re:Zoom improvements requested by music schools by telesilla on Thursday January 14, 2021 @06:57PM (#25784886)
This shows actual network latency between regions.

https://www.cloudping.co/grid

Even with the state of the art equipment, transcontinental music making will always exclude the kinds of music that most of us play while in the same room together.

Re:Zoom improvements requested by music schools by Retric on Thursday January 14, 2021 @09:12PM (#25786109)
I was specifically mentioning 1,000km as the metric.

AWS latency isn’t great between regions. Looking on some other sites you can see London to NYC is 70ms, but that’s also 5,500km which is far behind the 1,000km mentioned. Ex: https://wondernetwork.com/pings/London

70ms /5.5 = 12.7 ms seconds round trip. The speed of sound is only 1,125 ft/s, and half that for round trips so 1,000km over fiber is the equivalent of ~7.14 feet apart in the same room plus whatever latency your personal computer and software adds.

Re:Zoom improvements requested by music schools by toast0 on Thursday January 14, 2021 @07:49PM (#25785406)
My DSL line gives me a 20 ms roundtrip to the first hop. My only choices at this address are DSL, LTE (latency seems highly variable, and much more expensive than DSL), or paying at least $50k to get muni fiber installed. So latency will always be an issue here.

Well, I could probably get some form of POTS either analog or ISDN/T1

Re:Zoom improvements requested by music schools by nullc on Friday January 15, 2021 @03:40PM (#25796119)
DSL is pretty much the worst of the wireline services as far as latency goes. Even some of the wireless technologies are better.

If you use sonic, at least in some areas they have a setting where you can turn down the level of forward error correction and get lower latency in exchange for somewhat higher packet loss.

Re:Zoom improvements requested by music schools by coldtea on Thursday January 14, 2021 @07:17PM (#25785105)
>Network delay can be just a few milliseconds even across a city

Sure. If you constraint it a little more, you can also just play to the persons in the next room directly (no streaming required).

For country level or worse global collaboration latency will always be a problem however...

Re:Zoom improvements requested by music schools by lordnacho on Thursday January 14, 2021 @07:07PM (#25784996)
Jitter is an issue as well. If the packets get routed in different ways the variability in latency might annoy you. Ever had a video call where the person gets really slow and then speeds up again?
Re:Zoom improvements requested by music schools by nullc on Thursday January 14, 2021 @07:11PM (#25785044)
For extremely low latency audio, you simply convert most jitter into loss (and the rest into added delay). How annoying the loss depends on the quality of the loss concealment.

If your conferencing is 'slowing down' and 'speeding up' then it's simply not a realtime communications medium.

Re:Zoom improvements requested by music schools by aeyes on Friday January 15, 2021 @07:36AM (#25790208)
> Network delay can be just a few milliseconds even across a city, assuming that no latency murdering devices (wifi or nics in interrupt mitigation mode) are on the path.

Even with fiber all ISPs I have ever used at home have latency murdering devices between my modem and their connection to the Internet. And I have to go through these hops even if I connect to an IP on the same IP.

Best I ever got was 12ms. Once you connect your laptop to the Internet in a data center you will instantly know what I mean.