Michael Niedermayer 0293b8a027 avfilter/drawutils: cover the alpha plane fully when blending ...

Blending took the colour's own alpha as the value written into the
alpha plane, weighted by that same alpha once more, so a translucent
colour left less alpha behind than it covered: half transparent red over
a transparent canvas ended with alpha 64 instead of 128, and drawn over
opaque content it even punched a hole into the alpha plane. The colour's
transparency is already part of the coverage, so the alpha plane takes
full coverage, which is source-over compositing.

The drawutils test program checks this and runs under FATE.

Assisted-by: Claude

2026-09-26 11:36:30 +00:00

..

.gitignore

…

drawutils.c

avfilter/drawutils: cover the alpha plane fully when blending

2026-09-26 11:36:30 +00:00

drawvg.c

avfilter/drawvg: limit VGS parser recursion depth

2026-02-03 21:07:29 +00:00

filtfmts.c

…

formats.c

…

integral.c

…