Each animation page contains the entire animation in reduced resolution MPEG-1 format.
Why MPEG-1? We needed to use a format with common viewers available for UNIX, Macintosh, and
Windows systems. This format had to have a high level of compression and still have enough
resolution to show the animation clearly. MPEG-1 satisfies these requirements.
There are two types of MPEG-1 formats used. Many animations are digitized from the
original video tapes at a resolution of 352 pixels wide by 240 pixels high by
29.97 frames per second. Once again, these pixels are not square, and the animations
should be viewed at a 4 to 3 aspect, or 320 pixels wide by 240 pixels high. A compliant
MPEG viewer should handle this aspect change transparently. Some of our more recent animations
are digitized from the original animation frames and use square pixels at a resolution of 320
pixels wide by 240 pixels high by 29.97 frames per second.
Here are links to some of the more common MPEG-1 viewers we know about:
QuickTime - Windows, Macintosh
MPlayer - Linux
Windows Media Player - Windows, Macintosh
Some animation pages also have QuickTime preview versions, which can be viewed with the QuickTime
viewer referenced here.
High Definition Animations (MPEG-2s and MPEG-4s)
Some of our animations are also included in a high definition MPEG-2 format. As a rule, these
animations are either 1920 x 1080 x 30 frames/sec or 1280 x 720 x 30
frames/sec, and cannot be played without specialized hardware decoders. These animations are provided for
specialized uses, such as museum displays or live presentations. Here are links to
several of the decoders for these formats:
Electrosonic HD Video Server
Apple's Quicktime MPEG-2 Plugin (not free)
If you have a newer (i.e. faster) computer, we've found a few software players that can play many of these MPEG-2s at full resolution with reasonable fidelity. Two options we've used are:
VideoLAN which has players for Windows, MacOS X, and Linux.
MPlayer which is primarily Linux but has a MacOS X port available as well (http://mplayerosx.sourceforge.net/).
MPEG-4 (.mp4) movie files can be viewed through QuickTime for Windows and Macintosh operating systems. We use MPlayer to play MPEG-4 movie files on Linux computers.
Our animation pages usually display one or more small images in JPEG or PNG format that illustrate the
content of the animation. Larger images are called print resolution images and are provided in TIFF
format for downloading. Print resolution stills often have a size of 2560 pixels
wide by 1920 pixels high, which is about 8.5 inches by 6.5 inches when printed at 300 dots per inch.
Warning: There is a generic problem with some TIFF files in that they can get reversed top-to-bottom
if the display software is not completely compliant with TIFF specifications. If you want to use
a TIFF image from our site, please check that the image is being displayed correctly in your
application, possibly by checking it with the smaller JPEG version of the image on our website.