Fast Gamma Correction Software?

Discussion in 'Video to DVD' started by TedDavid, Jun 3, 2005.

  1. TedDavid

    TedDavid Member

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    In a recent thread, I mentioned that a 45 min video took Nero Vision Express about 37 hours to encode. I had captured DV from my camcorder, which was saved as .AVI files, end proceeded to make a movie, trimming clips, adding text at each new chapter, gamma correction, creating menu, etc. Then I exported the movie to disk: MPEG2,high quality, 2-pass encoder. The transcoding took 37 hours.

    I have conducted some experiments since then. I took one of the AVI files and after trimming, simply exported the 3min clip as I had before. This time it took only 27 minutes, to my surprise. I imported the converted MPEG back into NVE and added text and gamma correction. Exported again, same encoder and quality. It predicted 10 hours ETA for the transcoding, so I aborted it. Went back into the NVE editor and removed the gamma correction, but left the text. Exporting again, it now predicted 1 hour.

    Seems like gamma correction is the big culprit in time consumption. Is there any fast gamma correction software for either AVI or MPEG video?

    Ted David
     
  2. TedDavid

    TedDavid Member

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    Since I posted the original, I have conducted further, more conclusive experiments. Starting with a 1 minute clip, I exported the movie without any titles or effects. Then I added gamma correction to the same clip and re-exported it. For the final experiment, I used NVE's Pixel Multiply effect in place of gamma correction, and re-exported. Here are the details.

    Test Processing Time Subjective Impressions

    No Effect 6min 10sec Dimly lit scenes poor, well lit OK
    Gamma Corr. 29min 50sec Dimly lit scenes OK, well lit scenes washed out
    Pixel Mult. 9min 46sec Dimly lit scenes better, well lit scenes washed out

    Starting format AVI Type-1, 720X480
    Duration 1 min 0 sec
    Aspect 4:3
    Encoding to MPEG2, Best quality, two-pass encoder

    Overall best is pixel multiplication. Is probably quicker because it is not a non-linear effect like gamma correction. It still would be good to find a fast gamma correction package.
     
  3. rebootjim

    rebootjim Active member

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    Try using virtualdubmod and frameserving, or avisynth, if you're into some coding.
     

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