Created attachment 133889 [details]
Exempi seems to fall into infinite loop when extracting XMP from the attached file:
$ exempi -x inf-loop.qt
processing file inf-loop.qt
dump_xmp for file inf-loop.qt
Tested with git master (b1859382628b5ba961548980e3b0725d6f934b20).
Found using American Fuzzy Lop:
Fix in git 886cd1d2314755adb1f4cdb99c16ff00830f0331 (2.4.x branch)
Thanks for the report.