Video editors are like elephants; your impression is largely formed by how and where you touch the beast.
Even worse, to a large degree, your impressions are formed by what you use and what you know. Even the most objective reviewer would have a hard time characterizing an editor he or she has worked with for many years as unintuitive, while new editing environments always seem foreign and forbidding. When focusing on objective comparative criteria, like output quality, how do you account for the reality that a reviewer will generally prove more proficient with a familiar program, and know which knobs and dials to turn to produce absolute top quality?
In our search for an "objective" comparison of video editors, here's what we came up with:
- We selected five of the top prosumer editors: Adobe Premiere Pro (MSRP $699), Apple Final Cut Pro 4 ($999), Avid Xpress Pro ($1,695), Pinnacle Liquid Edition 5.5 ($699), and Sony's Vegas 4.0d ($559).
- We created four multipart projects in each program, focusing on critical functions like video overlay, color correction, slow motion, and image stabilization.
- We sent the project files, assets, and our results files to each company with a detailed listing of problem areas that our tests had uncovered, inviting each company to call or write with their comments.
- Four of the five companies responded with corrections, explanations, and admissions. The only company who didn't respond was Apple, though provided the same lead time as the other companies.
Then, we compared the output quality of the files produced. This is what we found.
Video overlay is a capability that allows video editors to place portions of one video over another, or to impose logos and other images over videos. The most common technique is to shoot one video against a blue or green screen, and then combine the two videos, using a technique called "keying" to remove the green or blue background. This is how the weatherperson appears over the weather map on your nightly news.
All tested programs support video overlay, though feature depth varies to a degree. First, most offer a number of keying techniques, including chroma or color keying, which removes the background color, luminance key, which keys on differences in the brightness of the clip, and alpha-channel keying, which removes the alpha channel from the video or still image. Our tests analyzed color keying and alpha-channel keying.
With color keying, there are two basic levels of features. Typically, you use the eyedropper to choose the background color in the clip to be overlaid that tells the video editor which color to key out or eliminate when combining the two clips. Most programs also have a color tolerance value that increases the range of colors eliminated during keying, and edge controls that soften or feather the edge of the overlaid clip.
(Click http://www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=8108 to see basic color keying functions we used in our tests.)
The second layer of features consists primarily of spill suppression, which converts the background color to grayscale, which blends more easily than the distinct blue or greens used for most real-world keying. Basically, the theory is if you can't get rid of all traces of the blue or green background, make it as unobtrusive as possible. We used this feature when necessary and available.
Other advanced features include secondary color keying, which allows you to replace one solid color in the video with another; for example, converting a yellow car to red. We did not test secondary color correction, but note its availability in the Overlay features table.
Our overlay tests consisted of three ten-second segments, each with three layers, with three videos requiring chroma keying, two spinning logo files with an alpha channel, and one spinning EMedia logo. Two of the three chroma key files were DV source footage, with the other a 270x240-resolution raw AVI file zoomed to 2X before keying. We created the spinning logos in Ulead's Cool 3D Studio and downloaded the EMedia logo from www.emedialive.com.
In comparing the results, we looked at a number of factors, including the integrity of the edges of the overlaid images, video clarity, and degradation to the spinning logo, analyzing several captured still images and the video during live playback.