Interframe Compression

In our last post, we covered intraframe compression - easy to edit, high quality, and inexpensive to implement. It sounded dreamy. But there are some issues.

Let's say you want to implement a tape-based HD acquisition format. The world already knows and loves cheap and cheerful miniDV tapes. Why not just put HD on those? Well, HD is more than four times the number of pixels, so we need to run the tape four times faster. Suddenly your 60 minute tape is only good for about 12 minutes. Even worse, you need to engineer motors, write heads, and lots of other bits that work reliably at four times the speed. And you need to hope that those miniDV tapes won't spontaneously combust. Clearly, this will not do.

Intraframe Compression

Serious video compression is a mix of math, science, and black arts. Discussion of the many esoteric features of modern compression technology is well beyond the scope of this blog, and is better dealt with by folks like Jason Garrett-Glaser. However, there are a couple bits of terminology we want to review so that we can better discuss workflow and post production technologies. In this post, we're going to discuss intraframe compression. In the next post, we'll cover its controversial brother, interframe compression.