Low delay audio streaming over the internet

[corrados]

Hi,

I've just finished the initial version of an open source software enabling low delay audio streams over the internet. Using this software it is possible to play together with other musicians in a "virtual studio".

A first successful test was made with a connection from Germany to Norway. I used a DSL-internet connection (1Mbps downstream, 256kbps upstream) and I got an approximate overall delay of 40 ms.

Requirements for using this software is: having a Soundblaster sound card (Live and Audigy was successfully tested), a Linux installed and an internet connection with at least 200 kbps up/downstream and a low ping delay (I have approx. 21 ms ping time to the server with a jitter of approx. 2-3 ms). Then, a server must be found where the server software is running which has a very fast internet connection, and, of course, also a Linux running.

If you are interested in the software, just check this out:
http://llcon.sourceforge.net
https://sourceforge.net/projects/llcon

Another interesting project is ldas, also a low delay audio streamer, but this software has the focus on high fidelity and it won't work with a regular DSL line or cable modem. Here is the link:
http://www.q2s.ntnu.no/~asbjs/ldas/ldas.html


It's really amazing what is possible to do nowadays. And the internet technology is getting better and better...

Volker

[Klown]

That sounds awesome, if a lot like advertising.

You have to have Linux installed for it to work?

I'm not sure many people here will be interested since the vast majority of people on this forum are Windows users.

Also, you should really have posted it in The Media Center (http://www.musicianforums.com/forums/forumdisplay.php?f=89) since it's really more computer related.

[Liberi Fatali]

Also, you should really have posted it in The Media Center (http://www.musicianforums.com/forums/forumdisplay.php?f=89) since it's really more computer related.
Moved.

But I don't mind advertising like this, hes not posting specifically to advertise.

Unfortunately I can't experiment with that stuff, due to my Windows OS. :-/

[corrados]

Yea, that's a pitty that most computer users are running Windows. It is actually possible to run llcon under Windows but it does not make any sense since the delay introduced by the Windows sound card interface is about 100 ms... Also, it runs very instable under Windows.

And yes, you are right, my initial post sound really a lot like an advertisment. But what I intended with my post was to see how many people are interested in such a software and share my enthusiasm. I'm very enthusiastic about it since I wrote a very long time on the software without knowing that my idea of connecting through the internet with very low delay would work at all. Since I had an actual jam-session through the internet last week, it was just awesome for me. Have you ever played music together with another musician who is over 1000 km away from you? :-)

[john123]

can you make one for windows?

and i dont have a server :(

[corrados]

can you make one for windows?...
one possibility would be to use the ASIO (Steinberg) audio driver but I have never used them and it is most probably a lot of work to implement this

[corrados]

It would be interesting to see what your ping times to a possible llcon server are. For my test I used a computer in the network of the Darmstadt University of Technology. It would be great if some of you could measure the ping time and post it in this thread.

For this measure, just open a command prompt (MS-DOS window) and type in:
ping www.tu-darmstadt.de

My ping results from Munich are as follows:

--- www-tu.hrz.tu-darmstadt.de ping statistics ---
75 packets transmitted, 75 received, 0% packet loss, time 74303ms
rtt min/avg/max/mdev = 20.482/21.880/23.075/0.587 ms

which shows that my average delay is about 22 ms.

[Light Fantastic]

Hmm well I'll try it and see what it's like but I don't know what I'm going to stream.


Edit: I get around 27ms delay.

[corrados]

I get around 27ms delay.
Thanks for the test. With the current implementation you would get an overall delay of approx. 45 ms which is acceptable for most instruments/vocals. Only with percussive instruments this might be a bit too high.
I guess you are not from the USA, otherwise you would not get such a pretty low delay.

[Klown]

I guess you are not from the USA, otherwise you would not get such a pretty low delay.
He's from the UK.

[corrados]

I just found another interesting link:
http://www.skype.com/share/stories/a-band-reunion-through-skype

Using Skype for this sounds a bit curious to me... The minimum reported round trip delay I ever had with Skype was around 80 ms. And I don't know how Skype manages conference calls. Is there some kind of server mixing signals together? If not, it will be hard to get everything synchronized properly...

[corrados]

I just finished the implementation of the ASIO audio interface for the llcon software. That means that with aa ASIO compatible sound card and a suitable ASIO driver llcon can now be run under Windows.

I'm quite impressed about the performance when llcon runs under Windows. I did not expect the ASIO interface to provide similar low latencies as the ALSA sound interface under Linux.

For some more information, just take a look at http://llcon.sourceforge.net