[FFmpeg-soc] libavfilter audio work - qualification task

Stefano Sabatini stefano.sabatini-lala at poste.it
Sun May 16 18:10:58 CEST 2010


On date Tuesday 2010-05-11 01:12:37 +0200, Stefano Sabatini encoded:
> On date Monday 2010-05-10 15:52:18 -0700, S.N. Hemanth Meenakshisundaram encoded:
> > On 05/10/2010 03:14 PM, Stefano Sabatini wrote:
> > >On date Sunday 2010-05-09 20:42:30 -0700, S.N. Hemanth Meenakshisundaram encoded:
> > >>On 05/03/2010 01:32 PM, Stefano Sabatini wrote:
> > >>>On date Monday 2010-05-03 01:11:07 -0700, S.N. Hemanth Meenakshisundaram encoded:
> > >>>>On 04/23/2010 05:03 PM, Stefano Sabatini wrote:
> > >>>>>On date Thursday 2010-04-22 17:19:16 -0700, S.N. Hemanth Meenakshisundaram encoded:
> > >>>>>[...]
> > >
> > >>+    /* FIXME: av_parse_color currently sets alpha to 0 if no alpha is specified.
> > >>+     * So we force alpha = 0xFF (opaque), here in such a case.
> > >>+     */
> > >>+    if (rgba[3] != 0)
> > >>+        color[3] = rgba[3];
> > >>+    else
> > >>+        color[3] = 0xFF;
> > >I suppose this was to be skipped.
> > 
> > If I skip this without the parseutils patch, then text specified
> > will be invisible (alpha 0) by default when user specifies
> > foreground color as an english string. So I left it in for the time
> > being. Will remove it along with parseutils patch. Hope that's ok.
> 
> Fine.
> 
> Did you already thought about a syntax? My idea was:
> color/0xXX
> color/DDD
> 
> maybe someone which works with web/design can suggest a more
> familiar/natural syntax though.
>  
> > >Apart those nits patch looks fine to me (but missing configure and
> > >documentation parts), I assume it has been tested and works.
> > 
> > Done. Other nits fixed and the redundant fixme removed. Tested and works.
> > 
> > >Please provide the complete patch.
> > 
> > vf_drawtext.c, allfilter.c and libavfilter Makefile changes are all
> > part of drawtext.diff which is a patch against soc/libavfilter (svn
> > diff ./ in soc/libavfilter directory)
> > 
> > There's no configure in soc/libavfilter, so config.diff is a patch
> > against ffmpeg trunk. Should this be in some other form?
> > 
> > drawtext_doc.diff is a diff with libavfilter.texi of ffmpeg trunk
> > after it has been patched by the checkout.sh script in
> > soc/libavfilter. I can make this a patch to the
> > 03_libavfilter_doc.diff file in soc/libavfilter if required.
> 
> No patch is OK, I think that I'll add a configure patch to soc too.
> 
> If no one else has other comments I'll apply the patch to soc in few
> days.

I had to edit the patch before to apply, there were different warnings
and a problem with the strftime() expansion rendering (only the
characters in the provided string where loaded in init(), that
couldn't work when the string was expanded), please test more
accurately the next time and never ignore warnings.

Also I changed the way the filter is configured, with the applied
patch the --enable-libfreetype switch is required to compile the
drawtext filter. That looks simpler and consistent with the way
configure deals with external libraries.

As for what regards the filter: the outline quality is honestly quite
bad especially at small font sizes, while I really appreciate the
font/box transparency feature :-). Also maybe we should try to add
anti-aliasing support.

Enjoy, regards.


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