[FFmpeg-devel] Bunch of questions from a newbie.

[Paul B Mahol]

Hi, Welcome,

On Tue, Jul 20, 2021 at 6:35 PM Paul Buxton <paulbuxton.mail at googlemail.com>
wrote:

> Hi everyone.
> I am planning on doingsome work on ffmpeg. The first thing I notice is that
> the Ubuntu build instructions on the wiki aren't currently working with
> Ubuntu 20. It seems that you need to install gnutls-dev as well as
> unistring-dev. Is there a review process for content on the wiki, or should
> I just add those dependencies?
>

Just add your changes.

>
> My plan is to implement a filter (or several) for correcting
> underwater video. The algorithm I will be using works in a couple of steps.
> 1. Analyse frame and calculate a corrective transform matrix
> 2. Apply transform matrix.
>
> Would you typically split these up into separate filters (so that they are
> reusable), or should I keep them as a single filter?
>

Just use single filter, I currently do not see need for separation.


> The filter operates in the RGB domain. Should I make the filter handle YUV
> as well by implementing a manual yuv to rgb conversion, or will the filter
> chain handle this automatically?
>

Filter chain does it automatically, so if filter's algorithm operate in RGB
just use RGB pixel formats.


>
> Is the input to a filter linear or gamma corrected?
>

It can be anything, but just typical values are used (they are certainly
not linear).

If for some reason filter operates in linear domain, use float RGB pixel
formats.


>
>
> Thanks,
> Paul
>


Regards


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