[FFmpeg-devel] [PATCH] [2/??] [3/3] Filter graphs - Parser for a graph description

[Aurelien Jacobs]

Vitor Sessak wrote:

> Hi
> 
> vmrsss wrote:
> 
> > The latter refers to the fact that all this is mathematically very  
> > solid and well defined, governed by a small set of equations (eg
> > swap, vflip*hflip  = hflip * vflip, swap).
> > 
> > I find this syntax clearly superior (there are only two well- 
> > formedness rules, no clumsy handling of names and aliases and  
> > danglers). If there is interest for this, I will elaborate.
> 
> Well, for me it is not yet clear which syntax is the best. For me,
> the strong points of your syntax is that it is elegant and need no
> labels. It's drawbacks are, in my opinion, that the syntax of the '!'
> is a bit ugly, it need one more operator more than the other syntax
> ('()*,!' against '(),;') and may be a little harder to learn.
> 
> About hardness to parse, I don't think one should be way easier to
> parse than the other.
> 
> Finally, a strong point of my implementation is that the code is
> already written ;-)
> 
> Well, I'm a little biased to say which syntax is the best, so I'd be 
> glad to hear the opinion of other people in the list...

I didn't had a deep look at the currently written parser (nor even
at libavfilter itself), but as a potential user, I really like the
"mathematical" syntax (ie. vmrsss one). It's more elegant and it seems
to allow shorter/clearer filter graph descriptions.
That's pretty subjective, but well, you asked for opinion :-)

Just my 2 cents.

Aurel