We did some test calls with our Jitsi Meet server using different
resolutions set to config.js. In test we used two Windows desktops running
Chrome 41.0 and Chrome 42.0 in other.
We tested resolution:'720', resolution:'480' resolution:'360' and
resolution:'180'. With higher resolution values video quality was better
and sharper. With higher values Windows task manager showed higher cpu
usage too. Strange thing was bandwidth usage. Despite different resolutions
both incoming and outgoing bandwidth (looked from Windows 8 task manager
performance tab) was almost identical.
What kind of mechanism is used for selecting bandwidth? With two
participants highest values we saw were 2 Mbps send, 2 Mbps receive. When
resolution was '180', bandwidth was initially much lower but after a minute
it had evenly raised to 2 Mbps send, 2 Mbps receive. That was the same
level what we saw in 720,480 and 360 settings too. For 320*180 and 640*360
2 Mbps send, 2 Mbps receive feels quite high.
In our config.js we had these settings:
openSctp: true, // Toggle to enable/disable SCTP channels
channelLastN: -1, // The default value of the channel attribute last-n.
useRtcpMux: true, // required for FF support useBundle: true, // required
for FF support
enableSimulcast: false, // blocks FF support
resolution:'180' // here tested '360' '480' '720