Calculating offset of shifted line

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Calculating offset of shifted line

Ulf Zibis
Hi,

I would like to calculate how much a special line in the video is
irregularly shifted to right or left. For this I want to compare the
line with the adjacent line above by calculating the minimum of the
quadratic mean for each shift.

I'm first looking for something like:
x:=0; y:=123; diff:= 0; while(x++ < in_w, diff += (luma(x,y) - luma(x,y
- 1))²);

So the first question is: how to get the luma value of a pixel?

Thanks

-Ulf

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Re: Calculating offset of shifted line

Ulf Zibis
Hi,

a polite ping ...

-Ulf

Am 09.01.19 um 01:22 schrieb Ulf Zibis:

> Hi,
>
> I would like to calculate how much a special line in the video is
> irregularly shifted to right or left. For this I want to compare the
> line with the adjacent line above by calculating the minimum of the
> quadratic mean for each shift.
>
> I'm first looking for something like:
> x:=0; y:=123; diff:= 0; while(x++ < in_w, diff += (luma(x,y) - luma(x,y
> - 1))²);
>
> So the first question is: how to get the luma value of a pixel?
>
> Thanks
>
> -Ulf
>
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Re: Calculating offset of shifted line

Carl Zwanzig
On 1/11/2019 1:11 AM, Ulf Zibis wrote:
> a polite ping ...

Certainly- please don't top-post on this list.





Regarding pixel values, it could be that nobody directly knows; could also
be that it's not possible from the command line.

You probably need to look into using the various ffmpeg libraries, and
they're discussed on a different mailing list.

z!
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