Video playback from Max

Todd Winkler (Todd_Winkler@Brown.edu)
Tue, 9 Feb 1999 20:02:27 -0500

My most recent dance piece uses David Rokeby's VNS to allow a dancer to
control a video projection using Max. Movement controls the video speed,
start point, end point, and looping. The imovie object in Max also controls
freeze frame and video direction (forward/backward). All of the video plays
from a standard Powerbook G3 using the internal 4 MB hard drive and the
ix3D Road Rocket to get video to the projector (acts as a second monitor
output). Max performs beautifully - the full screen video looks great, and
is very responsive. Here is what I did:

1. Put the entire video clip in a RAM Disk
I created a 125 MB RAM Disk that held a single Quicktime movie containing
ALL of the movie clips that I used for the project. (If you have a very
fast hard drive or an array, this step may not be necessary).

2. Compression
I used Cinepak compression at medium - high quality (you can play with the
quality setting with a trade off of file size vs. quality). I used Media
Cleaner Pro for the compression.

3. Frame Rate
I used 24 fps. If you can get away with 15 fps, that's even better. I can
see the jerkiness of the clip at 15 fps, whereas the motion at 24 fps looks
more realistic. Some people like the 15 fps "look."

4. Sound
To keep the file size down, I used 44.1, 16-bit, mono. (Other accompanying
sounds played in stereo).

It goes without saying that the final quality will depend on the original
video source material and your video digitizer.

_Todd