wmv1: check that the input buffer is large enough

Fixes null ptr deref
Fixes Ticket1367

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit f23a2418fb0ccc56fdae4dbf83a5994cc917c475)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
1 file changed