There are lots of ways to enumerate all the files inside the data folder of Processing sketch. Here are 2 of them. The first one uses the Java DirectoryStream class. The second one uses the static function walkFileTree from the Files class.
My artwork, 50 . Shades of Grey, won the Grand Prize of the Japan Media Art Festival 2015, Art Division. The award ceremony and exhibition will be held in Tokyo, Feb 2016. Here is the festival website.
I installed the new Processing 3.0 and its video library in Ubuntu and found that the Movie class could not display the digital video. It only played the audio track. The Capture class worked well. Afters some Google researches about the gstreamer package, I concluded that it can be the missing gstreamer0.10-ffmpeg module. By installing it again as described here, the Movie class worked fine.
The new Processing 3.0 beta is available in the Processing website for download. There are some changes in the internal operations that we may need to pay attention to in case our programs depend on them.