Trying to play videos with smplayer and mpv-0.33.0 as backend using vaapi output causes crashes in mpv with the following error message:
mpv: malloc.c:2394: sysmalloc: Assertion `(old_top == initial_top (av) && old_size == 0) || ((unsigned long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long) old_end & (pagesize - 1)) == 0)' failed.
Downgrading to <mpv-0.33.0 "fixes" the issue.
There's at least one similar report from an Arch Linux user:
Was the crash reproducible with every play or happened it random?
What was the smplayer version?
Is this fixed with latest versions?
mpv-0.33.0 is gone from the tree.
Using smplayer-21.10.0 with mpv-0.34.0 (added to my overlay) I can no longer reproduce this issue.