[FFmpeg-devel] [PATCH] lavfi: port mp test source

[Michael Niedermayer]

On Tue, Aug 09, 2011 at 08:59:53PM +0200, Stefano Sabatini wrote:
> On date Tuesday 2011-08-09 16:09:47 +0200, Michael Niedermayer encoded:
> > On Mon, Aug 08, 2011 at 02:43:15PM +0200, Stefano Sabatini wrote:
> > > ---
> > >  doc/filters.texi             |   57 ++++++
> > >  libavfilter/Makefile         |    1 +
> > >  libavfilter/allfilters.c     |    1 +
> > >  libavfilter/vsrc_mptestsrc.c |  392 ++++++++++++++++++++++++++++++++++++++++++
> > >  4 files changed, 451 insertions(+), 0 deletions(-)
> > >  create mode 100644 libavfilter/vsrc_mptestsrc.c
> > 
> > if it produces same output
> > then ok
> 
> After some comparation with showinfo, I had to change M_PI in my code
> with 3.141592654, at this point they issue the same output but with
> some behavior difference, for mp=test frames with number frame%30 are
> skipped, with mptestsrc they are not (which looks more correct).

the filter was used to reverse engeneer 8x8 dct based codecs and the
all black frames can be used to quickly spot where the different
parts of the test patterns start


> 
> mp=test tests offset ranges from 1 to 30, for mptestsrc it is from 0
> to 29.
> 
> Apart from that, the output with the same parameters is exactly the
> same with both sources. Are you fine with this?
>


> Should I use the vf_test.c 3.141592654 constant or prefer the more
> exact M_PI? (this will change the output)

definitly the more exact one


> 
> Let me also know if it is ok to relicense GPL -> LGPL, and if I can
> remove the corresponding mp=test code once I commit this.

you can remove the corresponding mp=test code
about LGPL, do you see a use case in a commercial application ?
The original use case was reverse engeneering closed source codecs

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

He who knows, does not speak. He who speaks, does not know. -- Lao Tsu
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