[FFmpeg-devel] [PATCH] lavfi: protection against premultiplied alpha (was: The patch series about premultiplied alpha)

[Niklas Haas]

On Sun, 03 Aug 2025 20:15:09 +0200 Nicolas George <george at nsup.org> wrote:
> Nicolas George (HE12025-08-03):
> > I will send the series here in a few hours.
>
> Here is a series of patch. I am absolutely not sure I found all the
> filters that could be flagged, but the rest can be done as the need
> arises.
>
> Not tested every filter, but it is pretty straightforward.
>
> I could not find how to download your patch series in a format suitable
> for git am from the monster, I used the v2 series, but it should not
> change anything.

I will repeat myself briefly here that such a flag should be an opt-out, not
an opt-in. Supporting premultiplied alpha should be the default assumption
unless provable otherwise.

On a side note, I don't think it's necessary to add a new "default" struct
just for one particular combination of flags; especially not if your intention
is (as you state) to have such flags for every other AVFrame property.