try to decode vp8 using ogv.js
r21655 allows us to serve up
.wasm files as
application/wasm and the browser will then load them correctly.
It's really impressive, but unfortunately we can't feed data into the decoder until this is implemented: issue 359: Implement OGVMediaSource (Media Source Extensions / MSE shim).
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2147