Xpra: Ticket #1869: video container "faststart"

As per ticket:1107#comment:16, we should implement buffer seeking so that the header ends up in the right place.

That's assuming that we still want video in a container, which is not terribly useful if browsers can't play video automatically.. (they're the only consumers of these formats).

Sat, 23 Jan 2021 05:35:56 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1869