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).
In BBB 0.81, the slide number was base 0, while the shape page number was
base 1. We already have a conditional for checking 0.9+; use that to
add a workaround for old BBB recordings.
The previous code assumed that if a shape event's timestamp was during the
time when a particular slide was visible, then the shape belonged to that
slide. This isn't always true with the text shapes, since a final close
event can be sent after the slide has switched.
For a more future-proof matching, use the presentation name and page number
fields on the shape events when available to match them with the appropriate
slide image.
gnuplot's auto-margins don't work well on this graph, so manually specify
the top/bottom (actually left/right - the graph is rotated 90°) to make
the bars fit better, particularly when using wide aspect ratio slides.
The code was previously dividing by the total number of votes rather than
the max number of votes, which meant it was underestimating the width of
the bars. In some cases, this meant that the label for number of votes would
overlap the percentages.
Fixes#3725
- Getting slide dimensions to properly set the panzoom event when deskshare stops.
- Sometimes there's a panzoom event with the deskshare image dimension at time=stop_timestamp+0.1. We remove it.
- Little refactoring
- Properly inserting deskshare panzoom events. We insert a panzoom event with the deskshare video dimensions and the deskshare start timestamp. Immediately, we insert another panzoom event with the previous slide dimensions and the deskshare stop timestamp, deleting any other panzoom event inside this interval of time.
- Handling when deskshare events occur in timestamp = 0.0
- For now, we are limiting the max dimensions to 1280x720
Pending issues:
- Image and ViewBox sizes are hardcoded (1280x720 - a full screen deskshare video). In order to work with region deskshare videos, we must get the flvs resolutions and set shapes.svg and panzooms accordingly.
- We're not considering the deskshare annotations history yet
This is a demo. Some issues:
- When sharing desktop, cursor is still relative to slides, and not to deskshare video;
- Need to show whiteboard canvas on top of deskshare video as well;
- Need more testing (audio/video sync, playback perfomance, multiple presenters and multiple deskshare events).
