About an hour ago I watched A Digital Video Primer for Geeks. This is, hands down and no exceptions, the best instructional video I’ve ever seen. It takes a complex, dry, detail-filled topic and presents it with lucid clarity and a sense of fun.
They’re not kidding about the “for geeks” part; the exposition is fast and dense and assumes the reader is able to handle having concepts as complex as Nyquist’s theorem thrown at them in one go. But the exposition is also very clear and direct, and delivered with a keen sense of which details need most emphasis. The effect is only secondarily to impart facts; what they’re attempting, successfully, is to give the viewer a feel for the subject matter, an overall grasp of how the pieces fit together which can be filled in by later deep-diving into the pieces.
Full marks to Monty for his delivery, which is excellent on all levels. I’m no slouch myself at presenting technical ideas in accessible language, but I will cheerfully admit that this is as good as me at the top of my form, or possibly better. I know how much skill and effort is concealed in making a performance like this look casual; if you don’t, just trust me that what Monty has pulled off here is quite impressive just as an act of presentation-fu.
And yes, this is a video – not just an e-book narrated by a well-spoken talking head. The uses of props, whiteboard, and special effects are tasteful and understatedly clever. I particularly enjoyed the playful use of special effects to illustrate things like sample-rate compression, signal-clipping artifacts and how YUV chroma representation actually works. That was a very effective way to tie those abstractions to experiential reality so the viewer won’t forget them.
The material was ideal for my level of knowledge at start. That is, if you have (a) programmer chops, (b) a bit of basic knowledge of the physics of sound, and (c) you’ve heard of Nyquist’s theorem before and broadly grasp the relationship between sampling rate and cutoff frequency, you’re going to eat the rest of the video up like candy. Probably (c) isn’t necessary; what it meant for me is that I started getting new material at the point where Monty explained about sample rates above 44.1 being a way to get away with cheaper bandpass filters.
In general, the production is unobtrusively immaculate. This is all the more impressive because it’s clear the piece was shot on a tiny budget. And it proudly announces at the end that only open-source tools were used. Creative Commons license, natch.
One final thing: On top of all its other virtues, this video is a lovely aesthetic expression of the hacker posture of mind. If you are a hacker, you will know what I mean by this when you watch it; if you aren’t, there is little to no point in my trying to explain. If you think you may be becoming a hacker, watch it twice. Then get a night’s sleep and watch it again. This will help you in broad and subtle ways.