[vlc-devel] Q: handling an experimental version

Riccardo Bernardini riccardo.bernardini at uniud.it
Mon Oct 11 16:53:29 CEST 2010

Thank you for your replies.  Let me ask a couple of more questions.

Quoting Rémi Denis-Courmont <remi at remlab.net>:

> There are currently two independent paths whereby SDP are parsed within
> VLC:
> SDP with a single RTP session (only one m-line) and a static RTP payload
> format are parsed by the SAP plugin. This simply converts the SDP into a
> VLC media location, typically "rtp://SRC_IP@DST_IP:DST_PORT". SDP with more
> than one m-line or dynamic RTP payload formats are parsed by the live555
> library through the RTSP/live555 plugin.

This is just a curiosity: why this "two paths" structure? Couldn't you  
use the live555 plugin in both cases?

> You can write your own SDP parser, so long as it falls back to live555 by
> default. Unfortunately, you would need to parse the whole SDP, including
> any would-be codec parameter. You would also need to re-implement (or copy)
> the RTP profile and any relevant RTP payload format.

This question is related to the previous one: why must I fall back to  
the live555 if I rewrite my own parser? Could deriving from the SDP  
parser in live555 be easier?

>> Any suggestions?
> I wish VLC would have a nicely layered RTP/SDP stack, but it does not. I
> realistically won't have time to write one in the foreseeable future, and I
> cannot promise it on behalf of someone else.

Hmmm... What kind of "interface" should this stack have?  What kind of  
"services" is expected to provide?  I'm not promising anything, but if  
the additional work is not excessive, we could try to write a new  
RTP/SDP stack (reusing as much as possible [but not more] the existing  
code, of course).  Maybe the new stack could make our work easier, if  
we can find a way to add our experimental code as a pluggable module.   
Where can we find more information about this or, at least, what are  
the source files involved?

Thank you for your help.


Riccardo Bernardini
DIEGM -- University of Udine
via delle Scienze 208
33100 Udine
Tel: +39-0432-55-8271
Fax: +39-0432-55-8251

SEMEL (SErvizio di Messaging ELettronico) - CSIT -Universita' di Udine

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