Fixes assertion failure
Fixes: 136f8b8d47af7892306625e597dee655/signal_sigabrt_7ffff6ae7cc9_8941_ab11bea57c84796418f481f873dc31ba.dvr_ms

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>