Streaming Media - August/September 2008 - (Page 59)

blurry face and vague blocks in the background, which were very noticeable during real-time playback, which cost Dicas points in the Motion Quality category. The MainConcept frame retains a very high contrast with good quality and a relatively homogenous background, while the Apple clip is slightly blurry, a bit faded, and noisier in the background. Initially, I thought that the fading in the Apple clip resulted from the fact that I was using a test clip prepared in Windows and then encoded on a Mac. However, then I noticed that the Dicas clip, which was produced on the same Mac as the Compressor clip, was not faded. Then, I compared two clips produced in Squeeze (running on an HP Windows workstation), one using the Apple codec, the other the MainConcept codec (Figure 7). As you can see in Figure 7, the two clips produced with the Apple codec are both faded, despite being produced on different platforms, while the MainConcept clip, produced by Squeeze on the same computer as the Squeeze-Apple clip, retains very good contrast. If you’re using the Apple codec with any encoding tool, you need to watch for fading, and you may improve your results by boosting color and/or saturation either in your editor or in the encoding tool. At the other end of the spectrum, if you’re used to bumping contrast and saturation prior to encoding and you plan on trying the MainConcept codec, run a few test encodes to make sure this is necessary. If anything, MainConcept—at least as applied by Carbon Coder— seemed to boost contrast during encoding, which generally produced a visually pleasing result. What about motion quality? In general, the MainConcept clip exhibited the fewest motion artifacts, though there were two clips, both with very hard-tocompress backgrounds, that gave MainConcept fits: One was a seminar shot against highly detailed wallpaper, and the other was an action sequence shot against a bright red curtain. At the other end of the spectrum was the Apple clip, which often exhibited artifact-related noise during real-time playback of high-motion clips. With hard-to-compress backgrounds, including the aforementioned seminar clip, the codec’s fading seemed to minimize some motion artifacts. In general, Dicas had across-the-board problems with clips with hard-to-compress backgrounds, especially the opera shot shown in Figure 6. Overall, while MainConcept clearly delivers the best quality, the difference in most scenes is relatively minor, and viewers wouldn’t notice the difference without side-by-side comparisons, which, of course, they may never have. If you shoot with easily compressable backgrounds, limit motion, and are generous with your file bandwidth, all codecs should produce a good result from your viewer’s perspective. On the other hand, if you’re dealing with WWW.STREAMINGMEDIA.COM 59 http://www.digital-rapids.com http://www.digital-rapids.com http://WWW.STREAMINGMEDIA.COM

Table of Contents Feed for the Digital Edition of Streaming Media - August/September 2008

Streaming Media - August/September 2008 Table of Contents No Doubt - Editor's Note Mo’ Videos, Mo’ Money: Solving the Problem of Network Cost Why Good Design Matters More Than Ever: Just. Press. Play. Technology and Business Trends by the Numbers High-Touch Encoding With Microsoft Expression Encoder 2 The State of the Content Delivery Market, 2008 Get a Life: New Tools Put Lifecasting Within Anyone’s Reach So Many Codecs, So Little Time: Comparing H.264 Files Using Codecs From Apple, Dicas, and MainConcept Writing an RFP for Maximum ROI: Things to Consider and Questions to Ask When Writing a Request for Proposal for a Corporate Webcasting System The Patent Wars Producing Screencams in Camtasia Studio Analyze That Using Video to Communicate Change for Business Success Intellectuals’ Property Rights

Streaming Media - August/September 2008

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