Most authors have agreed. Like with vo.c, we don't take module
declarations into consideration (see 0e09533c73).
Notable issues:
115bfb9762: the author has (probably) not agreed. The vf.c changes were
removed with the removal of filter DR, though (see c54fc507da).
7b25afd742: the same author adds VOCTRLs for deinterlacing switching at
runtime. Put them under a HAVE_GPL ifdef just to be sure. (It looks like
we could remove the VOCTRLs immediately, as they're needed only for some
compatibility things, but no need to do that yet.)
02b199e5e9: the author had a conditional agreement to LGPL, which
doesn't allow us to change it just yet, but the code added here was
completely removed anyway. (These days, the pts is passed as mp_image
field, and put_image is gone.)
3532cd532e: same author, but code removed with DR removal.
f0626e2f8d: same author, but code was moved to mp_image.c.
e5b4b495c3: agreed to LGPLv3+ only, but the code was removed in
cfa1f9e082 anyway.
086c324692: author was not asked - minor warning fix, but no mpv
includes malloc.h anymore.
e9d0a1d609: author was not asked - removed again in 33b62af947.
c260a1139d: author could not be reached - but this code was removed when
mpv changed the image allocation code to essentially use FFmpeg's
pixdesc.