Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Post by C. J. Cleg » Mon, 17 Apr 2006 23:09:30


I have been invited to work on what should be a simple application
that receives RTP audio and video streams and stores them on disk,
then serves them back on demand.

The platform is either VxWorks, LynxOS, or RTLinux, they haven't
decided yet which they want to use, but they would like the
implementation to be POSIX-compliant.

No signaling is involved; just receive the stream, store it on disk,
and serve it up on request.

I have a lot of experience in real time embedded software and some
experience in TCP / UDP / IP networking, but none in RTP or RTCP.

Can any of you recommend some good books or websites or online
tutorials that will help me learn what I need to learn to do this?

Thanks...
 
 
 

Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Post by Bill Co » Tue, 18 Apr 2006 01:25:47


The only info I know of on RTPs comes from Wind River.
They invented the things, after all. Have you used Google?

 
 
 

Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Post by C. J. Cleg » Tue, 18 Apr 2006 02:42:32


Yes, and got 29,400 hits. :-)

There were a few helpful links, though most of them deal with H.323
and associates, and that's not what I need right now.

Anyway, especially for books, I can get thousands of hits with no idea
which ones are any good and which ones are not, hence I was hoping to
get some recommendations from folks who have been there and done that.
 
 
 

Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Post by Bill Co » Tue, 18 Apr 2006 05:17:13


Yes. It's a general problem with VxWorks writing. There is is only one
book that I'm aware of written by people who knew diddly about VxWorks,
and they decided to abstract away most of the VxWorks-specific info that
they started with.

That book is called "Real-Time Concepts for Embedded Systems" by Qing Li
and Caroline Yao. And I'm not really recommending it. It's merely the
least bad book that I've seen relative to VxWorks.

Here's the Amazon reference:
http://www.yqcomputer.com/
 
 
 

Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Post by Larry » Tue, 18 Apr 2006 08:50:56

I'd start with the source and applications from openH323.org or
voxgratia.org (preferred). Both have complete implementations of the
entire H.323 protocol suite, including rtp/rtcp. There are excellent
libraries within these that can be used for your project. The
protocols themselves are really independent if the tcp stack - you'll
need to implement standard udp messaging, and the rtp/rtcp will be used
to generate the messages, along with the CODEC contents of the messages
(G.711, uLaw, etc).

There will be very little diffences in the protocols SW written for
linux or vxWorks - the socket interface to vxWorks is standard BSD.

One other suggestion - download the ethereal that has the Voip embedded
in it - you'll be able to analyze IP streams for VoIP traffic, save
them to disk, and playback the audio. Also can analyze jitter and does
excellent plots.

Good luck.. It's a fairly simple and fun project.

LC
 
 
 

Need help (suggestions for books, websites, etc.) learning about RTP / RTCP

Post by Larry » Tue, 18 Apr 2006 08:53:26

C.J - Also go through the tutorials included on openh323 and voxgratia
- they are excellent. You can go directly to the RTP/RTCP sections. I
think you can actually used the libraries provided without knowing the
details of the protocols.

lc