Subject: [AVT] Changes between verison 10 and 11 of the ipmr payload

From: Roni Even <[email-masked]>
Date: Thu, 04 Feb 2010 12:03:53 +0200

Hi,

There is a change between version 10 and 11 of
http://tools.ietf.org/wg/avt/draft-ietf-avt-rtp-ipmr/ 

Version 10 had the following text

BR (3 bits): base rate for core layer of frame(s) in this packet

      using the table for CR. Values in the range 0-5 indicate bitrates

      for core layer, same as for packet SHOULD be discarded. The base

      rate is the lowest rate for scalability, so speech payload can

      be scaled down not lower than BR value. If a received packet has

      BR > CR then during decoding it will be assumed that BR = CR.

While version 11 is

BR (3 bits): base rate for core layer of frame(s) in this packet 

      using the table for CR. The base rate is the lowest rate for

      scalability, so speech payload can be scaled down not lower than BR

      value. Packets with BR = 6 or BR > CR MUST be discarded.

My view is that this change reflects better the behavior since BR should not
be higher than CR.   Note that packets with CR=6 will also be discarded

Please comment if you are not happy with this change.

Roni Even

AVT co-chair