[FFmpeg-devel] [PATCH] Implement histogram equalization filter.

[Michael Niedermayer]

On Thu, Nov 25, 2010 at 01:59:06AM +0100, Stefano Sabatini wrote:
> On date Sunday 2010-11-21 18:57:46 +0100, Michael Niedermayer encoded:
> > On Sat, Nov 20, 2010 at 04:44:01PM +0100, Stefano Sabatini wrote:
> > > ---
> > >  configure                |    1 +
> > >  libavfilter/Makefile     |    1 +
> > >  libavfilter/allfilters.c |    1 +
> > >  libavfilter/vf_histeq.c  |  217 ++++++++++++++++++++++++++++++++++++++++++++++
> > >  4 files changed, 220 insertions(+), 0 deletions(-)
> > >  create mode 100644 libavfilter/vf_histeq.c
> > 
> > if you confirmed that this is binary identical to donalds filter then ok
> 
> Uhm no, VirtualDub works in RGB colorspace this in YUV colorspace. I

I was unaware of there being significnat changes between
your code and donalds code.

What we need is porting existing filters without introducing bugs.
The best way to do this is a wraper around libmpcodecs.
If filters are ported one by one they must NOT be changed.
Proposed improvments must be carefully tested and be seperate of the porting.
Without testing things will quickly become significantly worse and buggier
than a libmpcodecs wraper ever could have been.
Also it likely is better to keep the original filter and a changed filter
seperate so as it preserve the original. That way the changes need less strict
testing and review as little is lost if your personal eq filter messes up
chroma.

Summary
if we have 1 eq filter it must be carefully reviewed and tested.
if we have a donald_eq filter that is supposed to be exactly donalds its much easier
also if have a stefano_eq and a baptiste_eq theres no real need to test them,
for each ot just would be the maintainers decission on what to put in there
be that good or bad. But with a single eq filter that has to work as the user
has no alternative -> thus we cannot change it without extensive tests

i hope this makes sense as iam a bit tired already and should go sleeping;)

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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