[FFmpeg-user] Problem playing mp4 file

[JD]

Hi,
I downloaded from YT a video with the youtube-dl command as follows:

youtube-dl -f 227 -o BulletProof_Monk.mp4 
https://www.youtube.com/watch?v=n-XfagAzwHM

after the movie downloaded I tried to play it.

ffplay BulletProof_Monk.mp4

yields no audio, and video is all pixellated.

mplayer totally fails to play it. Ditto with mpv.

Firefox-66 can play it within firefox.

Need help playing this vid without firefox.

Thanx!!