Web Video for Magicians - a short tutorial by Ian Kendall

A very good place to start...Hello, and thanks for dropping by. Today we will be talking about web video, and how it can best be used by magicians. Actually, I'll be typing and you will be reading, but you get the general idea. Also, this is going to be pretty vanilla as far as web design goes, so don't expect too many background images or java applets...

Brown paper parcels all wrapped up in ribbons...first off, we need to learn a wee bit about the theory of compression and web video. Bear with me, it may sound a bit dull but knowing this stuff will make everything else a lot easier to grasp.

The Science Bit(rate)

Video is made up of lots of pictures that are shown one after the other, very quickly. If the pictures are shown fast enough our super dooper brains cannot tell them apart, and we see a moving image. Commercial video ranges from 24fps (frames per second) to 30fps, but to be honest anything over 15fps is a waste of time, since that is the lowest frame rate that the human eye can see as smooth motion. This leads to the first Big Lie:

Big Lie One: Always capture at 24/25/30 fps for the smoothest video.

By all means use this high frame rate if you are burning to DVD or VCD, but for web clips anything over 15fps is a waste of bandwidth.

What the heck does that mean? I'm glad you asked. No, honestly. This might be an opportune time to discuss bitrates and compression.

Bitrate is the amount of data that is encoded into the clip per second. For instance if the bitrate is set at 100kbps (a nice number in more than one way) then each second of video takes up 100 kilobits (which is about 12.5 kilobytes). This 12.5KB is spread over fifteen frames which means we have around 833B for each frame. So we have to squeeze our frame into 833 bytes...

I'm still interested...