[FFmpeg-devel] [PATCH] lavfi/testsrc2: fix completely transparent alpha.

[Carl Eugen Hoyos]

2017-07-21 15:51 GMT+02:00 Nicolas George <george at nsup.org>:
> Le tridi 3 thermidor, an CCXXV, Carl Eugen Hoyos a écrit :
>> alpha_value = x * 255 / width;
>> or
>> alpha_value = y * 255 / height;
>>
>> Sorry for being unclear, Carl Eugen
>
> Oh, you mean a gradient on the alpha channel. It is not really possible
> without making the code more complex and I think significantly slower.

> A coarse gradient between the different vertical bands is easy, but the
> alpha must be constant in each band, just like the color.

(Why?)

> A gradient on the undulating diagonal line is possible and easy, OTOH,
> since it already has a color gradient.

Any change that provides different transparency values on one frame is
a useful fix for a long-standing bug / missing feature imo.

Thank you, Carl Eugen