ff_clock_init expects a parameter with a pointer where it stores the
address of the newly allocated ff_clock, but ff_demuxer_reset does not
provide this parameter. That somehow writes the pointer to the ff_clock
into the packet->base->buf field on the stack of the ff_demuxer_reset
function. This later causes a segmentation fault when the packet is freed.
Closesjp9000/obs-studio#448
e96c7c86b6