[Retr0spectrum]

Mplayer can do this by default e.g.

    $ CACA_DRIVER=ncurses mplayer -quiet -vo caca video.avi

Here's the Silicon Valley intro in glorious ASCII: http://i.imgur.com/YKP6nfP.png

I had some audio sync issues with mplayer, and it sounds like termplay avoids that. I'm also not sure if there's a way to use true colour with mplayer.

[anonova]

mpv has a true color terminal renderer.[1] It's not the fastest though: http://i.imgur.com/919Rez5.png

  $ mpv --vo tct https://www.youtube.com/watch\?v\=PA4InNa0NSQ

[1]: https://mpv.io/manual/master/#video-output-drivers-tct

[jakeogh]

I had to --vo=tct (xterm was not happy around the letterbox borders!)

[LEGOlord208]

Yep, it does avoid sync issues... well, partly. It doesn't know anything about the audio as that is handled by a pretty high level library. But it does make sure the frames goes at the speed they should. So assuming the audio isn't lagging behind or ahead (which I haven't encountered yet), the image and audio should be synced.