There are many factors in creating web video which affect total download time. Some of the are:
Physical dimensions of the video window. Video in a 320x240 window is four times as large as video in a 160x120 window.
Video and audio quality. The lower the quality, the smaller the file size. Smaller files download faster.
Traffic. If you're the only one trying to download a video clip, you'll get it as quickly as your modem will allow. On the other hand, if you're downlading the same clip that 200 other people are also trying to get at, you're going to have to wait your turn in line.
You also have to understand that there are two types of video: "Streaming" video and "Download-first" video.
The concept behind download-first is fairly simple: You download the entire file, and then you watch it. These kinds of files require a lot of patience, but once you download one, you have it on your hard drive so that you can watch it over and over again.
With stremaing video, you watch as it is loading. Here's the catch: The video file must be small enough that the data comes into your computer as fast or faster than it plays on your screen. For someone with a 28k modem, that's a tiny video clip. That translates to poor quality video.
When creating video clips, we have to juggle all of these considerations around to come up with what we feel is the most practical solution. The creators of different websites all have their own ways of dealing with these issues. Ours was always to lean in the direction of higher quality video and slower download time.
When you watched the 30-minute video clip, you were definitely watching streaming video. If you're on a 56k modem, the video was probably rendered in a 160x120 window with high compression applied in order to squeeze it through a 56k line. (High compression translates to low quality).
For the teaching of dance steps, we find this solution impractical because you really need to have a clear view of what's going on, especially in the finer details of dancers' feet. Low-quality stremaing video is decent for general explanation and overview, but not very good as a tool for careful study and analysis of dance steps. And by the same token, high quality download-first video is impractical for simple explanations that only require a minimum of visual quality.
So for this reason, we've chosen to use two different video formats: High quality download-first video for live-action step demonstrations, and low to medium quality streaming format for the long, drawn-out explanations.
So why slideshows instead of low-quality video for the explanations? Again, we have a tendency to prefer visual quality, and the difference in visual quality between a slideshow and a streaming video of the same length is huge. True, you don't get the live action, but then you don't really need it. That's what the download-first video is for.
I also think that the web has unique advantages over conventional video, such as instant worldwide distribution, the ability to advance the video frame-by-frame, and the incorporation of additional multimedia elements and interactivity. Rather than trying to emulate conventional VHS video instruction, we like to try and take advantage of this medium by exploiting is strengths. If we try to use the web to do what VHS does so much better, than why not just go out and buy the VHS tape?
As the technology continues to improve, our choices may change in the future. Sometime down the road we'll probably be able to offer complete streaming instructional videos of any length to almost anyone. But for right now we're required to make choices. And these are the choices we've made so far.
Of course, we're willing to go with the flow, and if it turns out that the slideshows are unpopular, we'll stop doing them and try something else.
Sincerely,
Jonathan Atkinson www.ballroomdancers.com
