This patch is analogous to 20f9727018:
It hides the internal part of AVFilter by adding a new internal
structure FFFilter (declared in filters.h) that has an AVFilter
as its first member; the internal part of AVFilter is moved to
this new structure.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
A filter needs formats.h iff it uses FILTER_QUERY_FUNC();
since lots of filters have been switched to use something
else than FILTER_QUERY_FUNC, they don't need it any more,
but removing this header has been forgotten.
This commit does this; files with formats.h inclusion went down
from 304 to 139 here (it were 449 before the preceding commit).
While just at it, also improve the other headers a bit.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
