Just as information if others also run into this issue as it cost me quite a lot of time......
After upgrading to latest Opensuse Tumbleweed with ffmpeg 4.02, MariaDB 10.2.17 and Zoneminder 1.32 ZMC and ZMDC craashed with segfaults and RIP's..
Invested a lot of tie tracking down the issues and found 2 problems:
libswscale does not seem to cope with 32Bit images (camera-settings), chanign back to 24Bit solved the ZMC crashes
perl DBD::mysql connector crashes when reopening MariaDB databses. Discussed here: https://jira.mariadb.org/browse/CONC-316 and a temporary fix / PR here: https://github.com/perl5-dbi/DBD-mysql/pull/247
PS: feel free to ask if more details wanted/needed
EDIT1: seems with latest git version from 28.9.2018 it works again with 32Bit camera setting!