Can't output raw video

[Waoweens]

$ sanjuuni -i in.mp4 -r -o out.ccraw
frame 0/6572 (elapsed 00:00, remaining 00:03, inf fps)/usr/include/c++/12.2.1/bits/stl_vector.h:1142: std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::operator[](size_type) const [with _Tp = Vec3b; _Alloc = std::allocator<Vec3b>; const_reference = const Vec3b&; size_type = long unsigned int]: Assertion '__n < this->size()' failed.
Aborted (core dumped)

Arch Linux
sanjuuni-git 0.2~46+30dcabb-1 (AUR)
ffmpeg 2:5.1.2-1
poco 1.12.4-1
zlib 1:1.2.13-2