[Live-devel] testMPEG1or2AudioVideoToDarwin.exe doubt ????

[vittal raja sripada]

I was looking the way RTCP packet is being generated by RTCP.cpp. I was able
to understand the way is it being generated.I want to make sure if i did
understand it correctly.

The process of creating the Senders Report starts at sendReport( ), which
inturns call addReport( ) which would see if SR or RR should be generated.In
the addSR function call we generate the variables
appropiately like NTP timestamp,rtpTimestamp,packet count and octect
count,which would get us the required SR packet.

Then we need to add the SDES packet to it(as every RTCP packet has to be a
compound packet according to RFC), we will call the appropiate function here
addSDES( ),in this function again we generate appropiate variables like
version,padding,count,length,ssrc.

We also need to add the CNAME SDES item which is mandatory.

When i saw the CNAME format in the RFC it says first byte CNAME=1, lenght is
the next byte which gives the length of the following user and domain name
byte.We are adding END item at the end of the SDES Item list, according to
RFC it is neccessary to add END item after the CNAME to SDES packet. I'm
unable to figure out what exactly is being added when we add END item, i see
in the comments of the program that "END item(i.e zero bytes)"  what exactly
are we adding here.

Also i've a doubt regarding CNAME the RFC says first byte is  CNAME =1 so
first byte contains value 1, the next bytes contains the length of the
following user and domain name,so if i say the length is "x", it implies
that the next "x" bits after length contains the user and domain name am i
right here.

Also when we pack the SR and SDES together as one single packet are we
putting anything to distinguish those two packets or are we just packing
them together and send them.

Please help me in getting a better understanding of the above things.

-raja




----- Original Message ----- 
From: "Ross Finlayson" <finlayson at live.com>
To: "LIVE.COM Streaming Media - development & use" <live-devel at ns.live.com>
Sent: Monday, August 23, 2004 5:45 PM
Subject: Re: [Live-devel] testMPEG1or2AudioVideoToDarwin.exe doubt ????


>
> >as far as i understood every RTCP packet should be a compound packet, so
> >along with every Sender's Report we also send an SDES packet.i mean we
> >pack them together as an RTCP packet and send it,same is the case with
> >Receievers Report.did i understand it correctly ?
>
> Yes, but this is done automatically by the LIVE.COM RTCP implementation
> (see "RTCPInstance::sendReport()" in "RTCP.cpp"), so it's not something
> that you need to worry about.
>
>
> Ross Finlayson
> LIVE.COM
> <http://www.live.com/>
>
> _______________________________________________
> live-devel mailing list
> live-devel at lists.live.com
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>