change MP4 encoding crf from 18 to 15

wangzhibo

2025-08-04 f5106b912f1261fe633aa6bcdf10a4b7e74345aa

284b6616712911044e521b136fed7e1f49df56d6 目录中不存在 data/taijiniao/videos/横屏/IMG_2888.MOV