The default pipeline was fairly aggressive about quality, and could
be too expensive for some computers. Decrease the quality setting for
the vp8 codec from 10 to 8, and increase the speed setting from 2 to 6.
(Basically, quality affects the visual fidelity of the end result, while
speed affects how much CPU the encoder uses to get a high compression
ratio at that quality level.)
Remove videorate from the pipeline, since the GStreamer VP8 encoder can
handle variable-framerate streams. This means that we won't spend CPU
encoding duplicate frames added by videorate.
https://bugzilla.gnome.org/show_bug.cgi?id=669066
d4a26fbf4b