c3video for debconf #4

Posted: [Source]
Tags:  c3voc ccc debconf debian planet-debian video

This is a follow-up to my previous post related the DebConf videoteam using a new software stack for the next conferences: http://acaia.ca/~tiago/posts/c3video-for-dc-take-3/.

As mentioned before, C3TT provides a set of scripts which will work in background for most reviewing and video processing tasks. The first will just check if the talk is done and mark the related ticket as recorded.

The second script, B-mount4cut, does a nice job by mounting a custom fuse filesystem providing the following files (more detailed explanation here:

uncut.dv: full original dv file used as input file for the final trimming.

project.kdenlive: Kdenlive project file for the operator. Once it's saved with the trim marks, fuse-vdv will do a parse on it and use the marks for cutting.

cut.dv: contains only the frames between the trim marks extracted from project.kdenlive.

cut-complete.dv: contains the frames between the trim marks extracted from project.kdenlive, plus a prepended intro and an appended video. Paths for these files should be previously set in the web interface as properties Processing.Path.Outro and Processing.Path.Intros. The outro file can be, for instance, an appended video file with a common thanks for sponsors. The intro files is usually an individual frame for each talk, being a colorful presentation poster. We can also set the intro duration in the Processing.Duration.Intro property.

cut.wav: demuxed audio from cut.dv

Note: in fact, fuse-vdv provides virtual video files as a concatenation of original input files, so avoiding copying large and redundant data. Ideally, these fuse mountpoints will be shared over the network for operators via glusterFS, but I'll skip that for now.

After adding the trimming marks and saving the project using Kdenlive, the operator should go to the web interface and mark the ticket as cut:

/images/c3tt_cut.png

Mark ticket as cut

Note: I've been able to do the marks in Kdenlive using double-click in the video, then editing the crop start/end options. The buttons "[" and "]" didn't work in my Kdenlive version for some unknown reason.

In the current DebConf video environment I had to make a link builder for translating the path/file names to the C3TT format. So, for the Amsterdam/2015-08-13/09:57:02.dv we should have a amsterdam-2015.08.13-09_57_02.dv symlink.

From now the system will delivery the next tasks to C-cut-postprocessor script. This script will just check the marks from the Kdenlive project file and do the cutting job. So far it has worked perfectly here for the first video sessions in DebCamp, with zero hack in the original code, wow!

Next post will be about the encoding script, named D-encoding.