cat * > new.mp4
More Details:https://www.tecmint.com/13-basic-cat-command-examples-in-linux/
ffmpeg.exe -allowed_extensions ALL -i xx.m3u8 -c copy -bsf:a aac_adtstoasc filename.mp4
批量改后缀
ren *.* *.ts
原文：https://www.cnblogs.com/xuxml/p/13258806.html