[FFmpeg-devel] [PATCH 2/3] Add section describing the filtergraph.

[Stefano Sabatini]

On date Sunday 2010-11-14 05:07:22 +0100, Michael Niedermayer encoded:
> On Sat, Nov 13, 2010 at 10:27:29AM +0100, Stefano Sabatini wrote:
> > On date Saturday 2010-11-13 02:25:47 +0100, Michael Niedermayer encoded:
> > > On Sat, Nov 13, 2010 at 01:51:09AM +0100, Stefano Sabatini wrote:
> > > > On date Friday 2010-11-12 19:22:55 +0100, Michael Niedermayer encoded:
> > > > > On Fri, Nov 12, 2010 at 01:32:55AM +0100, Stefano Sabatini wrote:
> > > > > > ---
> > > > > >  doc/filters.texi |   86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > > > > >  1 files changed, 86 insertions(+), 0 deletions(-)
> > > > > 
> > > > > This needs the attention of a english speaker
> > > > > 
> > > > > > 
> > > > > > diff --git a/doc/filters.texi b/doc/filters.texi
> > > > > > index 4750d32..d1ae815 100644
> > > > > > --- a/doc/filters.texi
> > > > > > +++ b/doc/filters.texi
> > > > > > @@ -1,3 +1,89 @@
> > > > > > + at chapter Filtergraph description
> > > > > > + at c man begin FILTERGRAPH DESCRIPTION
> > > > > > +
> > > > > > +A filtergraph is a graph of connected filters.
> > > > > > +
> > > > > > +Each filter instance has a variable number of inputs and output pads,
> > > > > > +which are used to connect it with other filters. A filter with no
> > > > > > +input pads is called "source", a filter with no output pads is called
> > > > > > +a "sink". A connection between an output pad and an input pad of a
> > > > > > +filter is called a "link".
> > > > > > +
> > > > > > + at section Filtergraph syntax
> > > > > > +
> > > > > > +A filtergraph can be represented using a textual representation, which
> > > > > > +is recognized by the @code{-vf} and @code{-af} options of the ff*
> > > > > > +tools, and by the @code{av_parse_graph()} function defined in
> > > > > > + at file{libavfilter/avfiltergraph}.
> > > > > > +
> > > > > > +A filtergraph is represented by a list of ";"-separated filterchain
> > > > > > +descriptions. Each filterchain represents a sequence of connected
> > > > > > +filterchain node filters (each one called "filternode").
> > > > > 
> > > > > you define filter instances and then use undefined terms like 
> > > > > filterchain node filters and filternode instead
> > > > > ive not reviewed further, this IMHO needs more work
> > > > 
> > > > I changed to:
> > > > |A filtergraph is represented by a list of ";"-separated filterchain
> > > > |descriptions. Each filterchain represents a sequence of connected
> > > > |filter instances, each one called filternode.
> > > 
> > > whats the difference between a filter instance and a filter node ?
> > 
> > |A filtergraph is a graph of connected filters.
> > |
> > |The node of a filtergraph is a single filter instance, which has a
> > |variable number of inputs and output pads, which are used to connect
> > |it with other filter nodes.
> 
> thats not ok
> you talk about filter instance and filter nodes and The node (one)
> of a filtergraph.
> None of this is defined or makes sense or is needed, you should pick one
> word and stick to it not mix words that mean slightly different things in
> contexts that _require_ identical things.
> 
> Iam a bit tired but if i have to try id say
> 
> A filtergraph is a directed graph of filters. It can contain cycles,
> and there can be multiple links between a pair of filters.
> Each link has one input pad on one side connecting it to one filter from which
> it takes its input and one output pad on the other side connecting it to the
> one filter accepting its output.

Thanks, fixed together with some other remarks.

English speakers and especially people which has no familiarity with
the filtergraph syntax are welcome to comment.

Regards.
-- 
FFmpeg = Formidable & Friendly Merciful Peaceless Easy God