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The Video Codecs: A Catalog > The Video Codecs: A Catalog - Pg. 307

It's not intended for compressing iMovie masterpieces. ·Cinepak. This compressor produces very tiny QuickTime fles. Unfortunately, the compromises are severe: The picture quality is often greatly degraded, and the compression and saving process takes a very long time. ·BMP,PNG,Photo-JPEG,JPEG2000,PNG,TIFF.You may recognize these formats as popular still image fle formats. Remember that QuickTime is designed to be a Grand Central Station for multimedia fles of all kinds--not just movies, but sound fles and graphics fles as well. These graphics-format options are largely irrelevant to movies. (They appear in your Compressor list because they're among QuickTime's master list of codecs, all of which are made available to QuickTime- savvy software programs like iMovie.) ·ComponentVideo.In the era before digital video, you could convert footage from your camcorder into a digital fle only if you had a digitizing card, an expensive circuit board for this purpose. Component Video is the format these digitizing cards used, because it could store video extremely quickly on your hard drive during the digitizing (capturing) process. It was designed for real-time recording speed, not for compression. The fles it creates require huge tracts of disk space. ·DV-PAL, DVCPRO-PAL. These options are here so that you can export your iMovie masterpiece in the European video format (PAL), while retaining full DV size and frame rate. (DVCPRO is a slight variant of the DV format, intended for use with super-expensive professional broadcast TV video gear.) Unfortunately, the quality of the video suffers when you make this kind of con- version, especially in action scenes. ·DV/DVCPRO-NTSC. Suppose you've just completed a masterful movie, and the thought of compressing it to some much smaller, image-degraded QuickTime movie breaks your heart. You can use this codec to turn your fnished, effect-en- hanced, fully edited iMovie production into a new, raw DV clip, exactly like the DV clips in the Media folder in your project folder. You might do so if, for example, you wanted to import your entire movie into another DV-editing program, such as Final Cut Express or Final Cut Pro, or if you wanted to turn it into a Video CD or DVD, as described at the end of this chapter. (DV, of course, means digital video; NTSC is the format used in the Western Hemisphere and Japan.) ·Graphics.Uses a maximum of 256 colors to depict each frame. The result is grainy and blotchy. Use it only if your movie contains nothing but solid-colored images, such as cartoons, pie charts, or other computer-generated simple images. Even then, this aging codec doesn't compress the video very much. ·MotionJPEGA,MotionJPEGB. These codecs don't perform any temporal (frame- to-frame) compression. Each movie frame is saved as an individual, full-sized color picture. The disadvantage is, of course, that the resulting fles are extremely large. In fact, you need to buy a special circuit board for your computer just to play back this kind of movie. In other words, motion JPEG is occasionally useful when editing video, but never for distributing it. chapter12:fromimovietoquicktime The Video Codecs: A Catalog 307