Switch from JSON to binary encoding

[link2xt]

Something adhoc or bencode would be better than using readAsDataURL to base64-encode the payload. Realtime channels are capable of sending real binary data, no need to have base64 overhead.

[WofWca]

You're right, I wrote a TODO about this

webxdc-video-call/main.js

Lines 22 to 25 in c48eec8

	// TODO perf: it is more efficient to send video data directly as
	// video arrayBuffer instead of converting back and forth to strings
	// and back.
	const payload = JSON.parse(new TextDecoder().decode(data));

It was just the quickest way to fork off of the original code.