Streaming Media - June/July 2008 - (Page 59) should consider. First, you want to Table 3 — File Extensions for H.264 Files Produced for Flash Playback deliver the highest-quality video. Second, since advanced encoding File Extension FTYP MIME Type Description options produce a file that’s harder to .f4v ‘F4V ‘ video/mp4 Video for Adobe Flash Player decompress, you want to ensure that .f4p ‘F4P ‘ video/mp4 Protected Media for Adobe Flash Player .f4a ‘F4A ‘ audio/mp4 Audio for Adobe Flash Player your file plays smoothly on your target .f4b ‘F4B ‘ audio/mp4 Audio Book for Adobe Flash Player computers. Finally, for those producing massive amounts of files, you want a set of configuration options that will produce your files in a reasonable amount of time. Let’s discuss the low-resolution file first. Note that I The first question I wanted to answer was how much produced the two low-res comparison files in four of a quality difference exists between a file encoded encoders: Adobe Premiere Pro 3.1.1, Episode Pro (4.4.1), using the Baseline Profile and a file produced using the Sorenson Squeeze 5, and Rhozet Carbon Coder 3.0, which Main Profile with all quality-related options enabled. offered, by far, the most configuration options. For this Then, the question became, “How much slower did the reason and in the interest of time and space, I’ll make the file play back on mid- to low-end computers?” most comments about the Carbon Coder results. To test this, I encoded two files to two different sets of In terms of quality, as you can see in Figure 2, the encoding parameters. The first was my standard DV tricked-out Main Profile produced better results, though codec test file, which I produced at 640x480 resolution, these were primarily visible during high-motion 29.97 frames per second, at 468Kbps video/32Kbps sequences. In low-motion, talking-head scenes, the two audio. The second was an HDV source file that I first videos were nearly identical. Note that this finding was produced at 720p at a data rate of 4,000Kbps relatively consistent among the various encoding tools. video/128Kbps audio, then produced again at So, we know that the advanced encoding parameters 1,500Kbps video/128Kbps audio. In both cases, I prodeliver better quality, but what does it cost us in playback duced the file twice, once using the Baseline Profile and speed? To measure this, I played the files back on four next using the Main Profile with all quality-related different computers, ranging from an old Dell Latitude options enabled. notebook to a Dell Precision 390 workstation (see Table 4). The EventDV.net Research Center includes the following categories: PRODUCTION 3D and Effects Software Live Event Tips & Techniques Camcorders HD & HDV Lighting Audio POSTPRODUCTION Editing & Authoring Tips & Techniques NLEs DVD Authoring Tools DVD Duplicators and Printers Stock Imagery & Audio Clips Streaming & Encoding Video Cards & Displays Take part in the weekly EventDV.net SURVEY! Subscribe to the EventDV Spotlight weekly newsletter! Visit the EventDV SHOWCASE Spotlight on EventDV.net! WWW.STREAMINGMEDIA.COM 59 http://EventDV.net http://EventDV.net http://EventDV.net http://EventDV.net http://WWW.STREAMINGMEDIA.COM
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