[FFmpeg-devel] [PATCH]Warn all lavf users if ac3 (dts, pcm) is muxed into mpeg-1 system

[Reimar Döffinger]

On Fri, Nov 22, 2013 at 01:26:35PM +0100, Michael Niedermayer wrote:
> On Fri, Nov 22, 2013 at 12:17:34AM +0100, Carl Eugen Hoyos wrote:
> > Hi!
> > 
> > Attached is a second variant of the mpeg-1 system warning patch 
> > (as suggested by Michael).
> > 
> 
> > This still assumes that ac-3 (dts, pcm) in MPEG-1 System is valid, 
> > I don't know if this is true.
> 
> i cant say without reading mpeg 1 systems and probably various
> specs based on top of it that i dont have access to ...
> maybe someone else knows ?

I do not know, but as far as I could tell from the code it just seems
to be put into some "user type stream", with no indication of what it
is?
While not invalid, I'm fairly certain that wouldn't be in any
specification and the only way FFmpeg can play it back again is by
probing.
But I might also have misunderstood.

> > +            if (!strcmp(ctx->oformat->name, "mpeg") &&

I think it would be better to check the is_mpeg2 variables instead.