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Both are good questions.
Podner automatically preserves aspect ratio. If you drop a video encoded from a widescreen DVD, which should not include the black bars because they're not really part of the video stream, then you will end up with a video scaled to 320x240 such that the width of the video is 320 pixels but the height is scaled to preserve the original aspect ratio - which should be something like 173 pixels for your typical widescreen video. The iPod then centers the video vertically during playback, placing black bars to the top and bottom, just like a DVD works with your home theater TV. In the end, the black bars are not a part of Podner's output but they do appear because of the way the iPod displays the video.
We included the option to encode at 480x480 in MPEG-4 because that's Apple's stated maximum spec. In truth, there are folks out there who have pushed that spec to well over 600 pixels in at least one dimension, making it clear the MPEG-4 decoder on the iPod is a lot more forgiving than the H.264 decoder. With 480x480, the extra pixels wouldn't be ideal for playback on the iPod, which would scale it down to fit the iPod's 320x240 screen, but they could potentially provide a better picture if you connect your iPod to a TV/monitor. Given the iPod's current capabilities, I would say users are less likely to use it to tote full-length movies for the purpose of watching them on a friend's TV/monitor than they are to carry short clips for the same purpose - in which case the difference in resolution is probably not enough to warrant the extra file size and possible energy cost on the iPod because it has to work harder by scaling the video stream to fit the screen. Still, some users may want to use the higher resolution and we simply preserve aspect ratio just like we do with 320x240 encoding.
_________________ Keith GugliottoPrimordial Sea CaptainSplasm Software https://www.splasm.com
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