Tutorial: Shooting Top-Quality Streaming Video—How to Minimize Motion
I would avoid either Windows Media or H.264 at these parameters, but if you can’t, you should minimize motion in the video as much as possible. You have a bit more latitude when producing with Real or Flash, but should always take the conservative route, and not plan on the codec bailing you out if there’s too much motion in the video.
Now that you’re convinced that you’ll have to limit motion to produce high-quality, lower-bit rate streaming video, let’s examine how. In this section, we’ll discuss three sources of motion: your camera, your talent, and your editing. Later sections will describe how different backgrounds and poor lighting also contribute motion, in the form of noise, into your videos.
Limiting Camera Motion
Let’s face it: video without motion gets boring pretty quickly. The name of the game in streaming is to eliminate the extraneous motion so you can maximize the quality of the necessary motion.
What’s extraneous? Handheld video, for sure, so always use a tripod. Panning and zooming around a scene is also extraneous, so avoid that as well.
Shooting with multiple cameras is a great way to keep the viewer interested while retaining compression friendly video. For example, in a two person interview, you could switch from camera to camera, each shooting a different static view, moving from an establishing two shot to a close-up of the speakers. Since codecs handle infrequent sharp cuts fairly well, this would produce a much better image than panning and zooming around with one camera.
Similarly, if you were filming a surgical procedure or a mechanic changing a water pump, shoot your establishing without panning or zooming, then shoot the action with static cameras, perhaps switching back and for between close up and mid shot for variety. With a bit of creativity, you can create the illusion of motion that keeps the viewer’s interest, while limiting the actual motion the codec sees during compression.
Managing Your Talent
Obviously, on-camera movement causes your video degrade just as much as camera movement, which is why you have to advise your talent to minimize their motions. In addition, since you’ll likely be very tightly framed, any body motion could take the talent out of the frame, and arm-waving will almost certainly leave the frame.
Professionals can usually accommodate requests for limited motion, but most other speakers tend to be more worried about getting their talks out well than preserving compressed video quality. Placing speakers in a chair whenever possible is always a god idea, as is showing the speakers the poor quality of the compressed video on location while they have time to adjust their actions.
Edit Side
Once you’ve got the footage in the can, it’s important not to introduce more motion while editing. Probably the two biggest culprits are titles and transitions.
Programs like After Effect and LiveType make it fast and simple to create moving titles like that shown in Figure 7. However, while the motion and text effects look great for broadcast or DVD, as shown on the right, they look awful when compressed to say 100Kbps, as shown on the left. Figure 7 (below): While motion and text effects look great for broadcast or DVD, as shown on the right, they look awful when compressed to say 100Kbps, as shown on the left.
In video bound solely for streaming, stifle your creative urges and use simple titles with very limited motion. If you’re repurposing video originally produced for DVD or broadcast, and you’ve used titles with lots of motion, consider swapping in more simple titles for web distribution, since the text and other detail makes artifacts very obvious.
Ditto for transitions. Simple cuts work best, and short dissolves nearly as well. Get artsy with transitions bound for low-bit rate distribution, and you’re probably not going to be pleased with the post-encoding results.
Summary
1. Motion degrades the compressed quality of lower-bit rate video; if producing original video for low-bit rate distribution, you should limit the motion in your video.
2. Some codecs handle motion better than others, with Real and Flash (VP6) at the top, and Windows Media and H.264 at or near the bottom. Take this into account when planning your shoot.
3. Limit camera motion by using a tripod and limiting panning and zooming. Multiple cuts from shot to shot compress at much higher quality than panning or zooming.
4. Limit the motion of your subjects by advising them beforehand that excessive motion will degrade quality.
5. Creative editing that looks great for broadcast looks awful at low bit rates, particularly motion titles and fancy transitions.