Otherwise it can be 0 in sonic_decode_frame, causing SIGFPE crashes.
Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
(cherry picked from commit 58995f64)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>