Fixes: signed integer overflow: 1169365504 + 981452800 cannot be represented in type 'int'
Fixes: ticket8293

Found-by: Suhwan
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit e057e83a)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>