To shrink, or not to shrink: that is my question

Discussion in 'Multimedia (Windows Mobile)' started by jigwashere, Feb 1, 2011.

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  1. jigwashere

    jigwashere Life is a circus!

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    I have a simple, automated process to convert video using the H.264 MP4 codec type. To watch them on my smart phone, I had been using the iPhone preset (I think 420 pixels wide) but recently switched to another preset (720 pixels wide). My device is actually 800 pixels wide.

    The most noticeable difference is the resultant increase in file size. I'm not terribly concerned with video quality, and frankly don't really notice much difference between the two.

    Which preset is easier on my device? The narrower video has to be stretched by my media player to fill the screen, while the wider video does not. Does the processor work less if it doesn't need to stretch the video, or does greater resolution tax the processor more? :confused:

    The difference probably isn't a whole lot, so I'm mainly asking out of curiosity. Anyone know the answer? Thanks! :newpalm:
     
  2. Mi An

    Mi An Nexus Refugee

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    If h264 weren't accelerated on your device, I'd say the higher res would easily require more juice than scaling (based on my htpc experiences). But since it is accelerated, I have no clue. And since I have no clue, I wonder why I'm posting here?
    :confused:
     
  3. jigwashere

    jigwashere Life is a circus!

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    It's difficult for me to do any real testing since I don't know what other factors are part of the presets (e.g. frame rate). The 720 width preset seems a bit choppy at times.
     
  4. headcronie

    headcronie Greyscale. Nuff Said. Super Moderator

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    Less data to chew should equal better performance.
     
  5. Varjak

    Varjak Mobile Deity

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    This can of worms again (see all the Palm video threads)! Mi An is right, H.264 works best with devices that specifically are designed to handle it.

    You DO want to make sure to maintain the aspect ratio that fits the video AND best fits your screen. Picking a 'random' set of dimensions will be a problem. So if a movie is 1.85:1, you want to convert to screen dimensions that will maximize the coverage on your mobile's screen that also retains the right proportions. That may mean having black bars on ALL sides of your video (i.e. if you use 720 wide, figure out what the appropriate horizontal figure is). If you want to match the width of your mobile, simply solve for 800/x= aspect ratio of source material (usually 1.85, 2.35, 1.78 for HDTV programs, and 1.33 for older SDTV TV programs).
     
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