Subject: [AVT] rfc2733 - FEC

From: Danny Shavit <[email-masked]>
Date: Wed, 4 Sep 2002 11:16:50 +0200

Hello,

My question refers to rfc2733 - An RTP Payload Format for Generic Forward
Error Correction (http://www.faqs.org/rfcs/rfc2733.html).

According to my logics, in order to find the length of the reconstructed
media packet, we have to perform the XOR operation across the length fields
(7th field) of the bit strings of the media packets, and the length recovery
field of the FEC packet.

But, from the rfc, it is implied differently:

In section 8.1 which deals with the reconstruction process, in step 2, it
says: 
"For the FEC packet in T, compute the bit string in the same fashion, except
use the PT Recovery instead of Payload Type, TS Recovery instead of
Timestamp, and always set the CSRC list, extension, and padding to null."

What I think should be added is: " ... use the length recovery field instead
of 7th field of the bit string (a network-ordered representation of the
length of the packet excluding the 12 bytes header)."

Have I got it right?

Thanks,

Danny Shavit
VCON - R&D
Tel: 09 - 9590059 - (1) 255