[vlc-devel] Rép . : Re: commit: Qt4: fix default port numbers in streaming wizard ( Rémi Denis -Courmont )

Marian Ďurkovič md at bts.sk
Fri Nov 27 08:21:18 CET 2009

On Thu, 26 Nov 2009 21:11:26 +0200, Rémi Denis-Courmont wrote
> > Thus, default port is application matter.
> It means apps with a static default should use 5004-5005, in contrast 
> to apps that use a dynamic pair (such as RTSP clients).

Normative references in RFCs are printed in capitals. This one says we SHOULD
use even port number and we MAY use any. It doesn't even RECOMMEND to use 5004.

> VLC has been using 5004 on input by default since 0.9.0, for almost a 
> year and a half.

And none of the GUI users could ever notice that. That's IMHO the vast majority,
on Win perhaps almost all. Changing this in the bugfix branch and creating an
interop issues is certainly unwise, just leads to user confusion and adds extra
work for many people.

Again, there's no major motivation to switch from 1234 to 5004 except feeling
and taste. Both ports are perfectly valid according to the RFC, and such change,
although it looks trivial in the source, triggers much more hidden work at
network level and support level for *zero* benefit.

> Detecting whether a packet is TS or RTP is easy. But VLC plugins 
> cannot decide dynamically whether to use access or access_demux at the 
> moment, thus it's impossible.

That's just yet another argument to move TSoRTP back to udp access, which will
make it easily possible. The number of weird bugs caused by the fact that TSoRTP
is handled in access_demux is coming close to 10, and despite I fixed most of
them during last months, this one, ticket #3145 and who knows what else are
unfixable without architectural changes anyway. In any case, problems with the
current architecture are not a reason to change default port number.


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