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Hi,

i capture Voip Traffic and export the U-Law encoded payload to an au file as described in the online manual.

Unfortunately forward and reverse directions are not in sync. The incoming channel is always significantly shorter than the outgoing channel. From the quality analysis it sounds like the incoming channel is missing the silence packets. Or in other words. In the incoming channel, the silence periods are much shorter than they have been in the actual conversation. I believe, that silence Supression is used in this case.

Is there a way to export the RTP Payload and make sure that the exported Soundfile is in sync?

If the conversation is encoded using G711 A-law or G721, then the export is always in sync.

Anyone knows what the issue is?

Thanks!

asked 21 Sep '11, 09:56

Rocket's gravatar image

Rocket
1111
accept rate: 0%


Only standard G.711 A-law and µ-law streams are supported. Otherwise you'll have to save the RTP payloads and process the offline.

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answered 21 Sep '11, 12:53

Jaap's gravatar image

Jaap ♦
11.7k16101
accept rate: 14%

I understand that.

My Question is, why are u-law streams not in Sync, while A-Law streams are.

I'm not asking how to process them offline. I know how to do it.

I want to know what causes the streams to go out of sync.

(28 Sep '11, 02:00) Rocket

There is no difference based on the encoding, there's a difference when the RTP streams are different. Somehow your observed installation behaves differently under different circumstances.

(28 Sep '11, 02:34) Jaap ♦
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question asked: 21 Sep '11, 09:56

question was seen: 3,648 times

last updated: 28 Sep '11, 02:34

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