[FFmpeg-devel] [PATCH] swscale: set sane alpha blending defaults

[wm4]

On Sun, 30 Aug 2015 18:09:05 +0000 (UTC)
Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> wm4 <nfxjfg <at> googlemail.com> writes:
> 
> > Change the default to blend with black, which 
> > gives generally expected results.
> 
> Given that this introduces a speed regression, is 
> rarely needed and it is immediately visible that 
> the function is needed, I don't think this is a 
> sensible change.
> 
> Note that contrary to visual issue, the performance 
> regression is not immediately visible.
> 
> And "black" may be sensible for prores, in all 
> other cases, it is either suboptimal or bad.
> 
> Carl Eugen

PS: there is a 3rd way: make libswscale fail initialization if an alpha
conversion happens, but the user didn't specify the alpha mode.