In 2009, I stumbled across a “coming soon” solid state digital projector called UltraProjector. It was designed for use in things like Halloween haunted house. (It was originally $149, but today is $199.) The unit, which began shipping in October that year, was a totally silent, self contained low resolution projector (320×240) with audio output. Simply convert video to the proper AVI format, copy it to the device via USB, then turn and and watch it endlessly project the video clip(s).
I evaluated one of the prototypes and made the decision to order four of them when they began shipping, and we used them in several Haunted House attractions here in Des Moines, Iowa.
BUT, I quickly found out these units were not at all Mac friendly. First, there seemed to be only one program in the known world that could convert files that would play on it, and it was only available on Windows — some AVI Creator program, available as a free download.
(UltraProjector identifies itself as “ROCK MP3” and uses a China made chipset called Rockchip.)
Some intense research showed a secondary program, ViDrop, which could create videos — maybe — and it was a graphical frontend to “mencoder,” an open source converter program that is also available for Mac.
This blog post is just a placeholder to document my attempts to convert video on a Mac to use in the UltraProjector.
A bigger problem, though, is that bogus files on the UltraProjector file system make it lock up. When you plug it up to a Mac, Spotlight takes over and creates a few hidden “dot” files on the USB file system — which then render it dead!
Here’s a quick command line to remove those files. First, open up Terminal and then change directories over to the USB UltraProjector device:
alsmb:~ allenh$ cd /Volumes/NO\ NAME/
If you list the directory there, using the “-a” option, it will show “all” files, including invisible files (files that start with a dot as their first character):
alsmb:NO NAME allenh$ ls -a
. .Trashes Storybook and Audio.avi
There you can see the problem files — .Trashes, .Spotlight-V100, etc. Use the “rm” command with a few options to get rid of them. -R for recursive (so it goes in to each directory, deleting stuff), -d to tell it to remove directories, and -f to force the removal without prompting you each entry for verification:
alsmb:NO NAME allenh$ rm -R -d -f .*
rm: "." and ".." may not be removed
It’s okay that it cannot remove “.” and “..” — those are not real files, but references. “.” is the current directory (so an “ls .” shows where you are) and “..” is one directory up (“ls ..” would be “/Volumes”, in this example):
alsmb:NO NAME allenh$ ls -a
. .. Storybook and Audio.avi
You can see the dot files have been removed.
Up next … experiments with using mencoder to create proper AVI files for the device.
Stay tuned. I just wanted to get this uploaded so Google can start finding it…