vulkan_h264: check if slices_buf exists on end_frame

The issue is that while decode_slice is guaranteed to never get
called without start_frame, end_frame is not. Moreover, it is
not guaranteed it won't be called twice.

On a badly-broken sample, this is what happens, which leads to
a segfault, as vp->slices_buf doesn't exist, as it has been handed
off for decoding already and isn't owned by the frame.

Return an error as it's indicative that it's a corrupt stream rather
than just missing any slices.

Prevents a segfault.

0 files changed, 0 insertions, 0 deletions