This is just a bundle of a few things I've been fixing up in the past
while.
= Workaround for BBB 1.1 beta deskshare timestamp bug
This is unlikely to be used, but I have the code for it, might as
well merge it in.
= Rework video tiling code for ffmpeg
Render video using the 'hstack' and 'vstack' filters rather than the
'overlay' filter. This is somewhat faster, particularly with lots of
videos.
= Etc.
- Remove usage of the streamio-ffmpeg gem.
The video rendering code has some stuff to directly read 'ffprobe'
output, so re-use that instead of this gem (which is kind of old and
has issues with newer ffmpeg versions).
- Don't hardcode the deskshare video area size, pull it from the
properties file
- Remove some code that worked around missing video end events.
In some cases this could cause flickering or strange video issues.
It's no longer strictly needed, the new tiling code doesn't break if
the seekpoint is after the end of the video.
The new shapes code, required for handling smooth shape updates & multi-user
whiteboard in the 2.0 BigBlueButton, hits a bug in old recordings where
the pencil tool incorrectly used "line" in its shape names, meaning that
there could be both a pencil mark and a line with the same shape name.
The old recording code didn't rely on the shape name to match shapes, since
there was no chance of concurrent shapes. As this is an incompatible playback
change, we need to make a new playback directory for the updated files.
The old code was very difficult to follow, and I couldn't figure out
a good way to retrofit the BigBlueButton 2.0 undo by shape id and clear
by user id into it - so I rewrote the entire thing instead.
It now generates the shapes.svg, panzooms.xml and cursor.xml all at the
same time during a single pass through the event.xml file. The result
is compatible with the existing recording javascript (at least once a few
minor issues in writing.js were fixed by earlier commits).
The previous code would cause shapes to "blink" during updating if
the updates weren't continuous - in a gap between updates, the shape
would disappear.
Rework the logic for looking up "current" shapes to return the
nearest previous update rather than only exact matching timestamps,
and simplify the logic that decides whether to make a shape visible
or hidden.
