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Forums Compression Techniques MPEG Streamclip brightness problem

  • MPEG Streamclip brightness problem

  • Jeff Kubach

    July 8, 2009 at 7:48 pm

    I use a PC to digitize and then compress high resolution video. I use MPEG Streamclip to convert my uncompressed files into Quicktime files with the H.264 codec. I prefer the H.264 codec because I need smaller files for transfer via FTP.

    When I compare the uncompressed files with the H.264 Quicktime files, I notice that the Quicktime files have “crushed” black levels. That is, the different shades of dark gray and black all blend together and the overall “setup” level appears to be lower. The high end, or white end, of the spectrum appears the same, but those dark grays seemed to blend together and lose detail.

    My question is: do you happen to know of a good Brightness and Contrast adjustment number (in MPEG Streamclip) that would compensate for the crushed black level issue? I was fiddling with the “Adjustments” option to try to compensate and although I have found close matches, it still does not quite look correct

    If there isn’t a good way to compensate, is there perhaps another codec that matches the brightness and contrast better? One that is as small a file as H.264? Any thoughts on this would be greatly appreciated.

  • Rich Rubasch

    July 10, 2009 at 3:21 am

    Honestly, with the various codecs and PC setups, trial and error is your friend here. Do a short clip with a decent amount of gray to black and do some tests with gamma and brighness/contrast.

    It’s your best bet.

    Rich Rubasch
    Tilt Media

  • Daniel Low

    July 10, 2009 at 10:05 am

    Do a search here (and on google) for the Quicktime H.264 Gamma issue. It’s famous

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