[FFmpeg-devel] [WIP] lavfi: port mp/eq to a regular filter

[Michael Niedermayer]

On Tue, Sep 16, 2014 at 01:09:01AM +0200, James Darnley wrote:
> On 2014-09-15 00:46, James Darnley wrote:
> > ...
> 
> Update: I've got eq2 merged into the one file and working.  I would send
> another WIP patch but I've made several commits, all of which should be
> merged together.
> 

> One question I do have though is: should the user options for contrast
> in eq and eq2 be different?

iam not sure i understand
if theres one filter, how could there be 2 ways to specify contrast ?

also if you have 1 filter that implements
brightness/contrast/saturation/gamma correction
then depending on the parameters choosen by the user the operation
can be either done relativly easily in RGB&YUV or for example with
gamma it really needs RGB space
i dont think the eq2 gamma code make much sense


> eq has the range -1..1 (-100..100 in the
> original) with no change being 0.  eq2 has the range -2..2 with no
> change being 1 (a more obvious scaling factor) and a negative value
> inverting the image.  I don't know if this difference is desired or not.

being able to invert contrast and saturation is certainly interresting


> 
> There was some minor talk on IRC earlier about merging this with our
> current vf_hue, which itself is a port from libmpcodecs.  Is this
> something that people want?

is there code that could/would be shared ?
is usage easier for the user ?
actually i wonder if not seperate contrast/brightness an gamma filters
would be easier to use. It would be rather trivial to add such
filters on top of a eq filter

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In fact, the RIAA has been known to suggest that students drop out
of college or go to community college in order to be able to afford
settlements. -- The RIAA
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