[MEncoder-users] order in filter chain for eq2 and scale

[RC]

On Mon, 30 Mar 2009 10:41:14 +0200
Christian Ebert <blacktrash at gmx.net> wrote:

> What's the canonical order of the eq2 and scale filters?
> 
> So far I do eq2=<params>,scale. Is this correct or should it be
> the other way round?

The answer is VERY complex, as scale does the colorspace conversion.

eq2 works with the following formats:

    YVU9:
    IF09:
    YV12:
    I420:
    IYUV:
    Y800:
    Y8:
    444P:
    422P:
    411P:

If the decoder you're using isn't able to output one of those, the scale
filter IS going to be inserted before it, automatically by mplayer if
you don't do so yourself.  

If the encoder, or VO method you are using is also NOT able to use one
of those, then you ALSO need to have scale AFTER the filter(s) that need
the different color space.

This results in convoluted and seemingly nonsensical filter chains like:

  -vf format=yv12,scale,eq2,scale,format=bgr15

I actually needed to use something much like that for a couple years
(-vo gl).

So, to answer your question:  It depends...

-- 
Don't trust me! I'm wrong!