[FFmpeg-devel] [PATCH] Add vfilters.texi to documentation

[Stefano Sabatini]

On date Wednesday 2009-10-14 00:49:57 +0200, Diego Biurrun encoded:
> On Thu, Oct 08, 2009 at 11:54:05PM +0200, Stefano Sabatini wrote:
> > 
> > --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> > +++ ffmpeg/doc/vfilters.texi	2009-10-08 23:53:29.000000000 +0200
> > @@ -0,0 +1,82 @@
> > +
> > +Libavfilter is the filtering API of FFmpeg. It is the substitute of the
> > +now deprecated 'vhooks' and started as a Google Summer of Code project.
> > +
> > +Integrating libavfilter into the main FFmpeg repository is a work in
> > +progress. If you wish to try the unfinished development code of
> > +libavfilter then download it from the libavfilter SOC repository into
> > +some directory of your choice by:
> 
> Readers will likely be unfamiliar with the abbreviation SOC.

Referemce removed.
 
> s/download it/check it out/

Done.
 
> > +And then read @url{http://svn.ffmpeg.org/soc/libavfilter/README?view=co}
> 
> That's currently non-functional.  Just mention the README.

Fixed.

> > +The former video hook modules allowed a list of hooks, that would run
> > +in the order that they were specified on the ffmpeg command line.
> > +Each filter had one input and one output.
> 
> I'm not sure if talking about vhooks is useful.

Removed the mention.
 
> > + at example
> > +input --> split ---> fifo ----------------------> overlay --> output
> > +            |                                        ^
> > +            |                                        |
> > +            +------> fifo --> crop --> vflip --------+
> > + at end example
> 
> FIFO

I prefer to keep fifo, since that is the name used by an actual
filter, and the diagram clearly mention names of actual filters (as
opposed e.g. to a generic FIFO filter).
 
> > +splits the stream into two streams, sends one stream through the crop filter
> 
> splits the stream in two
> 
> > +overlaying it on top. You can use the following command to do this filtering:
> 
> You can use the following command to achieve this:
> 
> The command line is:
> 
> > +where input_video.avi has a vertical resolution of 480 pixels, the
> 
> s/,/./

Done.
 
> > +result should be that in output the top half of the video is mirrored
> > +onto the bottom half.
> 
> should be? :)

You can never be sure ;).

> > +Video filters are loaded using the @var{-vfilters} option to ffmpeg or
> > +to ffplay.
> 
> Options are not "to a program".  They belong to a program or are passed
> to it.  A program also has options or can be called with different
> options.
> 
> > The filters in the same linear chain are separated by
> 
> Filters in the
> 
> > +The magic labels @var{[in]} and @var{[out]} are respectively the points
> 
> s/respectively//
> 
> > +After the filter name, you may find the equal sign and a semicolon-separated
>
> May find?  And sometimes may not find?

Rephrased as:

Some filters take in input a list of parameters: they are specified
after the filter name and an equal sign, and are separated each other
by a semicolon.
 
> > +Following, a description of the currently available video filters.
> 
> I know it was my own suggestion, but this sounds awkward.  Try
> 
>   Below is a description

Changed.

Regards.
-- 
FFmpeg = Fierce Freak Muttering Patchable Epic Geisha
-------------- next part --------------
A non-text attachment was scrubbed...
Name: add-vfilter-doc.patch
Type: text/x-diff
Size: 3261 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20091014/89311ba2/attachment.patch>