[rasz]

The most likely reason for the error is badly decoded signature. YT uses &sig as a "crypto" access token (lasting couple of hours last time I checked). I have zero trouble playing dash videos in standalone mplayer (after manually extracting two video audio sources and decoding proper signatures).

[omarroth]

Only browsers have this restriction.

The issue I linked above doesn't appear to explain this. I would instead recommend reading this[0] comment.

0. https://github.com/omarroth/invidious/issues/177#issuecommen...

[rasz]

Ok, so CORS prevents from manual muxing/proper DASH player playback. How about two separate video audio tags with javascript synchronized playback/seeking?