[opus] Antw: [EXT] Is there a latency difference between uncompressed UDP (ie Jacktrip) and Opus?

Ulrich Windl Ulrich.Windl at rz.uni-regensburg.de
Mon Jul 19 06:11:34 UTC 2021

>>> Matt Keys <matt at mattkeys.net> schrieb am 14.06.2021 um 02:13 in Nachricht
<BN6PR19MB01149ED066FDBD1AA424C191AF319 at BN6PR19MB0114.namprd19.prod.outlook.com>

> Hello,
> I'm trying to find any existing documentation or test results of latency 
> differences between using Opus and uncompressed audio UDP streams such as 
> Jacktrip. I have posted my question to the Jacktrip users group here:
> https://groups.google.com/g/jacktrip‑users/c/xxMlqah1SKw 
> As well as to my general telephony network on LinkedIn here:

> 9031931904‑IuGQ
> The underlying question being ‑‑ which (opus stereo at 48k or uncompressed 
> UDP) is best for lowest latency and highest quality audio while assuming the

> endpoints are physically distant? As far as I can tell Jacktrip recommends 
> max distance of 250 miles or less between clients, and "Research suggests 
> it's very difficult to perform music with a delay greater than 25 
> milliseconds".

I would guess that delay is irrelevant for streaming, while jitter is not.
However with enough buffering I guess any distance will do.
Also the latency difference between Opus and UDP will become irrelevant as
sonn as the network delay exceeds some limit.
Maybe explain what your problem really is.


> I welcome suggestions on how to benchmark this latency difference, if any. I

> was thinking about using jack_iodelay and a loopback between audio in and 
> audio outputs while using baresip + jack + opus.
> Thanks,
> Matt

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