Subject: Re: [AVT] One more doubt regarding Jitter Buffer

From: "Desai Sunil Kumar" <[email-masked]>
Date: Thu, 12 Jul 2001 14:33:05 +0530

Hi Anand,
         U mean to say the Audio/Video Application will be maintaining the
timer & periodically it will be reading the data
from Jitter Buffer. In that case i have 2 doubts.

	1) If there is no data in Jitter buffer(more related to silence
suppression i believe).
	2) If there is data in Jitter Buffer, but application has not read &
a new packet has come should i overwrite.

	Regarding the Silence suppression the RFC 1890 says that the marker
bit in first packet should be set to indicate the begining of the talkspurt.
But how will know when the silence period has started. I read in some CNG
related AVT draft which says the SID(Silence Descriptor) frames are sent &
there is a payload type of 13 for CNG Payload. If u have any idea pl let me
know.

Reg
Sunil Desai			

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
http://www.ietf.org/mailman/listinfo/avt

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From: Colin Perkins <[email-masked]>
Date: Thu, 12 Jul 2001 09:40:36 -0400

>	1) If there is no data in Jitter buffer(more related to silence

The simplest approach is to play silence for the duration of the gap in the
playout buffer. You may also want to insert some form of appropriate noise,
generated locally.

>a new packet has come should i overwrite.

You will have to discard some data, yes.

>there is a payload type of 13 for CNG Payload. If u have any idea pl let me

You will know because no packets arrive, and there will be a gap in the
playout buffer (some codecs may also send comfort noise).

Colin

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From: "Lawrence A. Rowe" <[email-masked]>
Date: Thu, 12 Jul 2001 11:24:56 -0700

Hi -

Can I make a suggestion.  Desai, you should get a copy of the rat code
that is publicly available and read through that code carefully.  The
questions you are asking, all of which are excellent, are covered in
most of the high quality audio and video streaming tools for the
Internet.
	Larry

-- 
Professor Lawrence A. Rowe          Internet:  [email-masked]
Computer Science Division - EECS       Phone: 510-642-5117
University of California, Berkeley       Fax: 510-642-5615
Berkeley, CA 94720-1776            URL: http://bmrc.berkeley.edu/~larry