[FFmpeg-devel] Removing the "multicast=" tag from UDP URLs

Luca Abeni lucabe72
Fri Apr 11 11:53:11 CEST 2008

Hi all,

currently, the UDP URLProtocol in libavformat uses a
"multicast=" tag in the URL to decide if an address is
multicast or unicast. I believe this is a bad idea,
because it allows situations in which libavformat thinks
that "" is a multicast address, or ""
is unicast.

As a result, for example, the SDP demuxer is not able to
RTP receive streams directed to an unicast address.

I have a set of patches for removing the need for such
tag; I am currently testing them, and I'll post the
results on Monday. But I have a question:
to make everything as simple as possible, I am assuming
that a destination address can be multicast only if it
is provided as a numeric address (for example, the SDP
generator is not going to resolve an host name to check
if it is multicast or not). Is this reasonable?
If yes, wait for some patches on Monday... ;-)


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