Last updated 2016/03/22
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This document describes the scripts and procedures for running the technical aspects of Suffield's Dance-A-Thon. The Dance-A-Thon is a charit event put on by the students, faculty, and staff. The event runs all night (until early the next day), and involves a majority of the student body dancing at all times.
The event is a lot of fun, and generates many "media-worthy" moments. We typically take over 1,000 pictures and several short movies at the events. To help organize all of this information, we have created some computer scripts which sort, label, and upload these files to the school's web site.
Note: this document is intended primarily for Suffield staff preparing to use our software for the Dance-A-Thon. Others are welcome to use the software for other purposes, but we make no promises about its adaptability to other tasks.
The Dance-A-Thon is a several-hour-long event involving dancing, live music performances, contests, and games. Suffield uses technology during the Dance-A-Thon to accomplish the following tasks:
Because of the frantic pace of the Dance-A-Thon, there is not a lot of time nor manpower to handle these tasks. We therefore have created a series of scripts and procedures to help keep things flowing.
The Dance-A-Thon requires us to use several pieces of hardware, all of which must work together with each other, and with our software.
We've managed to hone our hardware requirements down to a single primary machine that does most of the work during the event. The machine has the following minimum requirements:
We currently use a dual-processor G5 computer from Apple, with a video card supporting two DVI outputs.
The computer provides a live streaming feed of the audio to other computers on the network. If you wish to receive this stream and play it, you will need another computer. In this case, the requirements are modest; any machine capable of receiving a QuickTime streaming broadcast will suffice.
For still photography, our scripts require that all photos have the same dimensions (they assume a statically computed size, to save on computations during image processing). Therefore, it is best to use the same model camera if multiple cameras are desired.
The scripts also make use of EXIF header information to determin image orientation. Therefore, the cameras must support this orientation metadata for the scripts to rotate the pictures correctly. If the cameras lack this feature, the user must manually rotate photos before processing.
We currently use Nikon D70 cameras (several of the people shooting photos have this model camera). The images are consistent, and the camera supports image orientation data.
For motion photography, we use a camera with the following features:
We currently use a Sony TVR-350 handheld camera. It supports a "nightshot" low-light mode, and can save recorded movies directly to 320x240 pixel 15fps MPEG1 movies.
The quality of the MPEG movies produced by the camera is substantially less than that of DV tape. However, the major benefit is that the movies do not need to be imported into the computer and saved into a compressed format; we simply upload the movies directly from the camera to our web server. Because the web site is the intended delivery mechanism, the file quality is acceptable for this use.
We provide a live "slide show" of photos from the event, updated throughout the eventing. Additionally, we show music videos, trivia contests, and other media via the primary computer.
Additionally, we sometimes directly attach the video camera to the projector to provide a live shot of the room for everyone to watch. Therefore, the projector should have an additional input that works with the camera (e.g., S-Video or composite). Many projectors provide a simple means for switching between inputs.
We use a few pieces of software to manage the files during the evening. Some of this software is available, and some we have create ourselves.
We have written a short perl script called sifter which takes a
folder of raw photos, renames them by date, and sifts them into
directories based on the time they were taken. The script then builds
an HTML gallery out of the photos (creating thumbnails as necessary).
The resulting gallery allows web users to quickly see all the pictures, and view larger sizes as needed. Additionally, a direct link to a photo ordering service is provided for each picture.
The script requires the jhead program for extracting EXIF
information from photos, and the jpegtran package for performing
lossless rotations of photos. Both programs are freely available, and
should compile cleanly on Mac OS X.
Additionally, the script requires the sips (scriptable image
processing system) binary, which comes pre-installed on all versions
of Mac OS X since 10.3. It provides extremely quick image
manipulation functions, such as resizing photos. We use it to make
thumbnails. SIPS could be easily replaced with other image
manipulation software (such as ImageMagick or NetPBM).
We have written a short perl script called vidindex which takes a
folder of raw MPEG videos and builds an HTML index to the files. The
script looks for an optional file for each movie that contains a
timestamp, title, and short description. If the file is found, the
script uses these values when building the HTML index.
Because there are not as many videos taken during the night, the video script does not take as complex an approach as the picture filtering script. All the videos are listed on a single page.
Once the photos and videos have been sifted, a short script called
sync may be called to upload the resulting galleries to our web
server. The script acts as a simple wrapper around rsync, which
provides a fast and efficient way to update only the files that have
changed since the last syncronization.
We use a passwordless SSH key so that the user does not need to enter a password to update the web site.
Additionally, the sync script supports a local (or remote, if
reconfigured) syncronization of the photos to a "slide show"
directory, so that the slide show photos can be easily updated
throughout the evening.
We stream the audio portion of the dance-a-thon over the network to other computers. The primary use of this stream is for computers elsewhere in the building where students may be taking a break between dances. Because they can hear the feed anywhere, they can return to the dance floor if they hear a song or event they'd like to participate in.
We use Apple's Darwin Streaming Server, which provides a quick and easy way to serve streaming media. The project is open-source, and precompiled binaries are available directly from Apple:
http://developer.apple.com/darwin/projects/streaming/
To author the live stream, we use Apple's QuickTime Broadcaster package. This product is available without charge from Apple:
http://www.apple.com/quicktime/broadcaster/
As a final note, we have created several .term files, which are
double-clickable under Mac OS X. These files simply launch the
command-line programs with the correct arguments.
This section serves as a guide for staff running the Dance-A-Thon using our setup. Please excuse the informal nature; this is intended mostly as "notes to self".
Set up a desktop machine (iMac or tower) with a local admin account (we use "suffieldacademy"). The software config currently assumes "/Users/Shared/Dance-A-Thon" as the base folder for the SVN checkout.
Install the developer tools and MacPorts on the target machine.
You'll need to install the jhead and jpeg to get the jhead
and jpegtran binaries.
For the Eye-Fi wireless SD card, you must use a non-enterprise AP. Local computer sharing won't work, and neither will multiple-AP setups where you can roam between points. Set up a dedicated AP and join the card to this.
Set the video camera to "nightshot" (not "super nightshot") mode.
Check out the scripts from the source repository, and locate the folder on your target machine. If you have a second hard drive with plenty of space, you might want to locate the software there.
Edit the GLOBALS.pl file to have the correct paths, dates, and
other variables for the scripts to run correctly.
If you want to do a dry run, try setting the year to "test" and
running the scripts. There's a picturefaker script which will
pave over the EXIF dates of a folder of pictures (faking them so they
appear to occur during the Dance-A-Thon that is yet to happen), so you
can try the scripts out.
On the web server, create the subfolder for the current year, and create an HTML file in the top level with the current year (just copy an existing one and modify). Symlink it as "index.html" in the year folder.
While you're on the web server, edit the config file for the virtual host that contains the Dance-A-Thon files. There should already be a configuration section; just edit what's there (if there isn't, search this repository for a vhost config that should have the settings).
The apache files aren't strictly required, but they help with a few things:
sifter script and commenting
out the Shutterfly order feature. That way, you can post the pictures
immediately, but not worry about messed up filenames from interfering
with orders. Once the Dance-A-Thon is done, you can confirm that the
files are named correctly, uncomment the icon, and issue one more
"build" command on the gallery.
At this point, you should have a functioning upload system, and you're
ready to go!
On the night of the Dance-A-Thon, things are pretty straightforward. Here's a basic checklist of functionality that should be working before the event starts:
sifter dirs to create the directory structure
sifter build and vidindex, which will create the empty
directories. Upload these empty directories so there's something to
see (instead of a 404) before you put up any pictures.
jhead, but it's a pain, so
it's easier to make sure everything is set before you start.
Once you've run through this checklist, you should be good to go. Drink plenty of water, and settle in for the night!
When it's all over, make sure you've downloaded all final pictures, indexed them, and uploaded the results. If you disabled Shutterfly links, confirm that the photos are correct, and then rebuild the gallery with Shutterfly support.
Once you're certain that the galleries are correct, re-edit the Apache configs and turn up the cache expiration time.