Re-sync out of sync live streams

[BenderB]

Hi Guys,

I'm testing an application I've created. It's basically a 2-way A/V chat, with
a text chat application on there as well.

Each user publishes a live stream, which is recorded on the server and then
resent back down to the other user.

I've been testing it locally and everything is fine, so I signed up to
Influxis on their Nitrous plan to give it a test run over the Internet.

Each stream is publishing a 32Kbps video + 8Kbps audio stream. Each user has a
fast broadband connection, with around a 140 ping to the server.

Over time, around 10 minutes or so, the live streams get quite far out of
sync. It can take over 20 seconds for the stream to reach the other person,
making a "live" chat quite useless.

If I stop and start the streams again, it brings everything back into line, so
I'm considering this as a potential resolution.

I'd really like to know why this sort of thing occurs, how I can minimise it,
and how to recover from it when it does happen.

Any help would be appreciated!

[namitagrawal]

Can you elaborate what mechanism is being used to publish live streams?

[BenderB]

Thanks for your quick response!

I setup the cams like this:

live_cam.setMode(320, 240, 15);
live_cam.setQuality(32768, 80);
live_cam.setKeyFrameInterval(20);
var live_mic:Microphone = Microphone.get();
live_mic.setRate(8);
live_mic.setSilenceLevel(20, 2000);
var live_cam:Camera = Camera.get();

Then start the netstreams:

var out_ns:NetStream;
out_ns = new NetStream(nc);
out_ns.attachAudio(live_mic);
out_ns.attachVideo(live_cam);
out_ns.publish("ns_tutorAV_CS", "live");

My server side code then grabs the Client Side live stream, and records it:

var ns_tutorAV = Stream.get("ns_tutorAV_SS");
ns_tutorAV.play("ns_tutorAV_CS",-1,-1);
ns_tutorAV.record("append");

The other client then receives the stream:

in_ns= new NetStream(nc);
in_ns.setBufferTime(0);
streaming_video.attachVideo(in_ns);
in_ns.play("ns_tutorAV_CS");

Sorry, couldn't work out how to attach code?

Thanks for your help!

[fmslove]

Which version for FMS are you using ?

your code seems fine to me; If it sure that application runs fine on your own
local setup; and problem comes only when you use Influxis setup, then you might
want to check with them for following settings :


- Server side buffer (should be minimum)
- Live aggregate messages (should be disabled) (applicable only in FMS 3.0)
- Audio Combine Samples (it should be completely off)

[Graeme Bull]

Increase the rate of the audio to 22. This will rid the app of latency, not what you would expect, but supposedly it works.