This patch is analogous to 20f972701806be20a77f808db332d9489343bb78:
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>
internal.h doesn't rely on it; instead include it directly
in every user that needs it (a filter needing it is basically
equivalent to it using FILTER_QUERY_FUNC, i.e. a majority of
filters doesn't need it).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
