[FFmpeg-devel] [PATCH] lavfi: port 2xsai filter from libmpcodecs

[Stefano Sabatini]

On date Sunday 2012-04-08 12:39:56 +0200, Stefano Sabatini encoded:
> On date Sunday 2012-04-08 00:07:43 +0200, Stefano Sabatini encoded:
> > On date Saturday 2012-04-07 23:58:28 +0200, Stefano Sabatini encoded:
> > > Based on the port by Nielkie <nielkie at gmail.com>, done for GCI 2010.
> > > Same output as the original filter.
> > > 
> > > See thread:
> > > Subject: [FFmpeg-devel] [PATCH] Port MPlayer 2xSaI filter to libavfilter
> > > Date: Thu, 25 Nov 2010 01:31:24 +1000
> > > ---
> > >  configure                   |    1 +
> > >  doc/filters.texi            |    7 +
> > >  libavfilter/Makefile        |    1 +
> > >  libavfilter/allfilters.c    |    1 +
> 
> > >  libavfilter/vf_super2xsai.c |  302 +++++++++++++++++++++++++++++++++++++++++++
> 
> Note also that the name of the filter is "super2xsai" rather than
> "2xsai" since an FFmpeg component can't start with a number (alternative
> names are welcome).
> 
> > >  5 files changed, 312 insertions(+), 0 deletions(-)
> > >  create mode 100644 libavfilter/vf_super2xsai.c
> > 
> > I had to rewrite the port basically from scratch, in order to check
> > where the Nielkie port was diverging. New variant is as fast as the
> > original, so I'll remove the libmpcodecs wrapped filter as I'll commit
> > this one.

After more benchmarking, I noted the performance was actually worst,
due to some unnecessary and redundant checks. New variant is as fast
as the original, and produce the same output.

> > 
> > [...]
> > > +        READ_COLOR(color[0][0], src_line[0], 0); color[0][1] = color[0][0]; READ_COLOR(color[0][2], src_line[0], 1); READ_COLOR(color[0][3], src_line[0], 2);
> > > +        READ_COLOR(color[1][0], src_line[1], 0); color[1][1] = color[1][0]; READ_COLOR(color[1][2], src_line[1], 1); READ_COLOR(color[1][3], src_line[1], 2);
> > > +        READ_COLOR(color[2][0], src_line[2], 0); color[2][1] = color[2][1]; READ_COLOR(color[2][2], src_line[2], 1); READ_COLOR(color[2][3], src_line[2], 2);
> >                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^
> > 
> > > +        READ_COLOR(color[3][0], src_line[3], 0); color[3][1] = color[3][0]; READ_COLOR(color[3][2], src_line[3], 1); READ_COLOR(color[3][3], src_line[3], 2);
> > 
> > This looks like an error, but I kept it for maintaining the same output.
> 
> I'll push the filter in a few days if I read no comments.

I'll apply tomorrow if I read no comments.
-- 
FFmpeg = Funny and Foolish Multipurpose Portable Egregious God
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