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GH13 Concert and Event settings 24p with file spanning
  • I'm starting this thread for people who are interested in a high quality, 24p, stable patch for events such as weddings, concerts, theater, poetry readings, lectures and so on. And pub crawls. Maybe impossible, but progress continues to be made.
    Although not always high art, I get a lot of requests to video a show, concert, event, wedding, etc., and these events typically are indoors, with poor or varied lighting.
    Sometimes these events run several hours. And for these events, I sometimes prefer the IQ of the GH13 over the GH2, at ISO 400-1000.
    My requirements are:
    24p for easy editing in Premiere and others. Premiere offers real time playback and effects with Mercury engine.
    Reasonably good IQ, regardless of the bitrate
    Minimal pulsing (some ppl don't see it but it drives me nuts)
    Fine grain at ISO 800 and usable 1600
    File spanning, in case I need continuous coverage
    Smooth transitions in shadows, given the limitations of the camera.
    Ability to use F/5.6 on a sharp lens in places that have good lighting
    Good IQ and grain with lens wide open in bad lighting.
    Plays back in camera so the highlights ("overs") can be checked, and also IQ checked on a monitor.
    Static scene bit rate 0f 20-24, typical of events and shows, or stages where there are a lot of fixed objects or open space
    Works on a Transcend 32gb Class 10 card or better

    First off, I would like to acknowledge all those who have done the real work, including Vitaliy, cbrandin, lpowell, blackout, rigs, and many more.
    Basis line: my starting point was the BP patch and lpowell's amazing high reliabilty patch. The HR patch has really served me well. It file spans reasonably well, has great IQ. It does not of course have 24p (hence the reliable part). The BP patch is also great, and is 24p, but did not span reliably. Another issue is that high bitrate patches often give low rates in low light. And theatre lighting with F/5.6 would occasionally lock up at 24p.
    Along came the rigs patch, which gives HIGH rates in low light and static scenes. My static scene bit rates doubled. Also, pulsing in shadow areas is minimized.I made three changes to this patch. First, I used the suggestion to raise the buffer to 84. Next, I lowered the overall bitrate in the regular section to 36 and the minimum to 22. I found that I could not see a big difference in static scene rates of 24 as opposed to the 33 I was getting in Rigs. Also, after a certain point it seemed that noise in shadow areas became slightly more visible after the bitrate exceeded 24.
    So far, in three days of testing, quality is good, file spanning is good and I get a solid 24 minutes per 4 gig chunk on my card--the reasonably priced Transcend 32gb. Mileage plus.

    Like all 24p patches, I suspect it will crash, so those who really need reliability should go for lpowell's high reliability patch. As with all patches, use at your own risk.
    I'm sure those better versed in the subtleties of the patch can make a better one, and I welcome suggestions.

    The zip file has the most conservative version of the patch. I will try to bump the bit rate up ten percent with the same stability,and also work on possibly a GOP of 8 or 6.
    DrDave Concert and Event patch GH13 Low V1.zip
    561B
  • 6 Replies sorted by
  • File-spanning is very time-consuming to test for absolutely reliable results. I've seen cases where the GH1 correctly spanned across to the second MTS file, only to fail on the third file. My general conclusions with 1080p were that bitrates above 28Mbps were likely to fail.

    FWIW, the most reliable file-spanning patch I found was the 720p29.97 3-frame GOP mode in my Fast Action 3-Frame GOP Patch:

    http://www.personal-view.com./talks/discussion/223/fast-action-3-frame-gop-patch-version-2-update-for-all-gf1-g2

    However, this patch will fail if the light level drops to near zero for longer than about 7 seconds...
  • Yes--it is very time consuming. So far, I have run about thirty tests of one to two hours.
    I had the issue that it would span the first time but not the second, so I adjusted the settings slightly. So far, so good. I get about five files in two hours, so it spans four times. Of course, only time will tell, but at least it is fairly reliable.
    I will do the "blackout test" to see if that is an issue. It occasionally happens in theatre productions, so that is an issue.
    Update--I ran it for several minutes in the dark, no problem.
  • @DrDave
    On the GH1, I found blackout failures to be a hazard on all short-GOP patches of less than 12 frames in 1080p mode. I also found the Pappas chart to be a good static test for file-spanning. Good luck, the best solution I was able to come up with was to use the "H" 720p mode for reduced-bitrate file spanning patches. Of course, this doesn't help with 24p...
  • Thanks--I'll stick with 12 frames--I wasn't looking forward to a week of GOP.
  • going to shoot with green screen in the studio with lighting. Is this patch good for that or which one would you recommnend?
  • I will defer to the Chromakey experts on that. This patch is for people who want native 24p, file spanning, and high bit rates on static scenes. If you don't need or want 24p, lpowells high reliabilty patch is a good place to start, but you may not get the highest bitrate on static scenes.