[FFmpeg-devel] [PATCH] Make rtpenc.c SSRC randomly set

Reimar Döffinger Reimar.Doeffinger
Fri Jul 11 18:53:35 CEST 2008

On Fri, Jul 11, 2008 at 12:23:38PM +0900, Luca Barbato wrote:
> M?ns Rullg?rd wrote:
> > If a unique, yet hard to predict, identifier is required, it can be
> > constructed from one unique (possibly predictable) part, and one
> > random (hard to predict) part.  Make the random part big enough to
> > satisfy whatever statistical properties are required.
> That is what the spec says, not what their example implementation does 
> though...

No, it says "randomly chosen value meant to be globally unique". Which
is about the same as starting a mathematical proof by "Let 1 = 2."...
"If a participant generates multiple streams in one RTP session, for example from
separate video cameras, each MUST be identified as a different SSRC."
My conclusion is: anything implementation that generates more than one
stream per session can not be compliant.
Now, specs are hardly ever perfect, but what I consider really bad is
that it is also completely unclear to me what they meant to say and why
they would want it.

Reimar D?ffinger

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