[FFmpeg-devel] [PATCH] Initialize ssrc properly in the RTP muxer

Martin Storsjö martin
Sun Mar 28 10:50:04 CEST 2010


On Sun, 28 Mar 2010, Michael Niedermayer wrote:

> 
> On Sun, Mar 28, 2010 at 01:23:48AM +0200, Martin Storsj? wrote:
> > On Sun, 28 Mar 2010, Luca Abeni wrote:
> > 
> > > Hi Martin,
> > > 
> > > On Sat, 2010-03-27 at 20:43 +0200, Martin Storsj? wrote:
> > > > When transmitting multiple RTP streams, their SSRC values should be 
> > > > unique. Currently, the RTP muxer has this hardcoded to 0. The attached 
> > > > patch replaces this (and also sets base_timestamp) using 
> > > > ff_get_random_seed().
> > > 
> > > Both ssrc and the initial timestamp used to be set with random(), but
> > > this has been changed because of security issues. If security people
> > > agree that ff_random_get_seed() can be used here, then I am of course ok
> > > with this patch.
> > 
> > Ok - if ff_random_get_seed() isn't allowed, av_gettime() or whatever is ok 
> > for me, too, as long as multiple streams don't have the same SSRC...
> 
> leaking the system time might not be ideal
> 
> ff_random_get_seed() should be ok though

Ok, applied.

And leaking the system time is more or less required (and done for other 
fields already) in RTP anyway, since it sends current realtime timestamps 
for all data anyway...

// Martin



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