This Echo Test demo just blindly sends you back whatever you send to it. You're basically attached to yourself, and so your audio and video you send to Janus are echoed back to you. The same is done for RTCP packets as well, with the information properly updated.
The demo also provides a few controls to manipulate the media
before you send them. You can mute audio and video, for
instance, which will tell the server to drop the frames and
not echo them back to you. You can also try and cap the
bitrate: such control will tell the server to manipulate the
RTCP REMB packets passing through, in order to simulate a
bandwidth limitation. In case you're interested in testing
simulcasting or SVC, add a ?simulcast=true (for
simulcast) or ?svc=<mode> (for SVC) query
string to the url of this page and reload it: buttons will
appear to allow you to try and switch between lower and higher
quality versions of the video you're capturing. Notice that
you may have to increase the bandwidth indicator to have the
higher quality versions appear, as the browser will not encode
them otherwise. Besides, notice that simulcast will only work
when using VP8 or H.264 (or, if you're using a recent version
of Chrome, VP9 and AV1 too), while SVC will only work if
you're using VP9 or AV1 on a browser that supports setting the
scalabilityMode.
Finally, this demo also includes Data Channels: whatever you write in the text box under your local video, will be sent via Data Channels to the plugins, modified by adding a fixed prefix, and sent back to you in the text area below the remote video.
janus.js, open
the
Devices demo
instead.
?plugin=lua query string to the url of this
page; to talk to the Duktape plugin instead, use
?plugin=duktape. Since they both share pretty
much the same syntax as the stock EchoTest plugin, most if not
all features should work just the same way.
Press the Start button above to launch the demo.