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Official Low GOP topic
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  • for the cinematic representation is GOP3 important
    but - must the extreme Mbps?
    I do not think so!
    not have a picture quality difference between 32, 42, 50, 60, 65 MBit can recognize

    i think, GOP3, 32 - 50 MBit is to time the best
  • @chip
    comparison of youtube v vimeo upload of the football clip - same file upload

    Versus

    Gareth Bale Scores - Panasonic GH2 Low GOP Test - Hi Bitrate from Nick Driftwood on Vimeo.



    Download the vimeo for an amazing rendition.

  • @driftwood

    Good to know, I think the slo mo would've looked like crap with a longer GOP. This stuff is looking so filmic to me. The shutter helps a lot, too. At 50 it's okay, I never go below. I use 60 the most, and even higher shutters don't bother me at all for action with the 3 GOP hack. Have you tried shooting night interiors at 2500 or 3200iso yet? It's wild but I actually LIKE the noise with the 3 GOP setting, it doesn't blur like it would at the longer GOP so it looks like film grain. I've been playing around with it even in day exteriors with heavy contrast in dynamic mode and the WB tweaked, almost gives a grainy, in camera Tony Scott bleach bypass look.
  • @chip
    'what do you use instead of vimeo?'

    Nothing. I just link to original files if I want to demo something, that way you guys can see it for real. But You Tube actually did an ok 1080p conversion for heavy motion 3 GOP stuff. I was surprised, Vimeo totally screwed up the motion cadence with their encoder.

  • Yes, smooth -2 -2 0 -2.
  • @chip, looks good. What was your film mode setting, smooth all the way down or something else?
  • @kae slow mo was done in post on fcp x by just a quick 50% slowdown. Looks nice dunnit?! And you should see the other clips - they look like England's 1966 World Cup Cinema film - amazing that stutter effect!!! :-)
    And ZERO problems with the 4gb file rollover whatsoever on a Transcend Type 10 32gb SDHC. Filmed continuously for 1hr 10mins.
  • I'll have to post the data, but the other day I shot 720 60P @ 35Mb/s 6-GOP and the codec broke on someone skateboarding in front of a fence. This footage was shot at 35Mb/s by accident. I meant to have shot it at 42Mb/s.
    I will post this data later
  • kae,
    what do you use instead of vimeo?

    shot outside today and got average videobitrate of 75Mb/s with kae's extreme 3-GOP settings, Transcend class 10, no errors.
    I expected this scene to be much more contrasty in camera but there's so much detail left in the shadows.
    Sequence 02_00147.jpg
    1920 x 1080 - 1M
  • @driftwood

    This stiff looks great. Vimeo really causes stutter in their transcodes for me so I don't use it. Was the speed change done in post for this, live in cam, or did vimeo screw it up? Either way, the footage looks just like film to me. Add a tiny bit of grain and it would be hard to tell the difference between it and 35mm, except projected on a 60' screen of course.
  • @sammy
    'once in a while also i would get the error of the gh2 not allowing me to record'

    Is that at other modes or 24p? If other modes? Check your ini settings for 720P, 1080i 60 mode. There are a lot floating around that people added to my 65MB settings or 60MB (Butts for example), some aren't stable for me that's why I made the combo patch with 12 gop settings. The 6 GOP settings do look better for those other modes however.
  • Kae setb 60MB 1080p 3GOP works fine with my Transcend 32 GB class 6
  • Glad you said that about skintones sammy, its something I noticed too shooting with the smooth profile outdoors in town the other day, they do look more natural. I thought I was imagining it. Not so sure about the motion, the 24p judder seems to be more noticeable under certain conditions, such as panning accross a deep horizon. I've been shooting with the GOP 3 hack for about a week now with no problems (although I'm sticking to the 60MB version, not the 65MB), under various conditions on a Sandisk Extreme Pro 45MB/s with zero problems. Going back to the motion issue, as it stands now if I plan to shoot scenes with high motion or panning shots I 'm switching to 1080i 50 hacked to 42mb/s which is beautiful (and shares the same GOP). Of course this means conforming footage later if I'm going to intercut.

    Edit : And yeah, intercutting progressive with interlaced footage is never going to be great. I'm working on methods to deal with judder in post too.
  • been using the 3 gop hack for a few days now, on sandisk extreme 16gb 30mb ..the few issues that i have had are
    1)even after i format the card after the hack, sometimes i would get the card error of the clip not being able to play the video,if i turn off the camera sometimes that error goes away,sometimes it stays even if i turn off the camera and turn it back on,so my question maybe is, do i have to format the card every time i turn on the camera >?or just the first time after the hack?
    2) once in a while also i would get the error of the gh2 not allowing me to record, i would hit record ,after a second it will turn off by its self, again i have to turn off the camera, and on again for this to work normal

    mainly i have been working with 24h, and 720 60p ,,and the results are a wow,i still have a hacked gh1, for me with this hack the first thing i noticed is that it grades much better than the hacked gh1 and the skin tones seem to me more smothers and natural and easier to the eye, the motion to my eye is a little better also, even compared to the hacked gh1 with gop of 1.
  • @kae how did you come up with 720p Top Setting=31878 and 720p Bottom Setting=22314?

    edit: never mind
  • @kae "Maybe in a future Ptools Vitaliy can separate them out."
    That would be awesome!
    For the time being I think I will just carry 2 small SD cards with different firmwares... and load the one I need for the shoot in question.
    But the 24p 52Mbits/6GOP files are very nice, too. They hold up quite well in 16bit postwork ... that's actually already more you can ask for with regard to donationware!
  • A quick sample from a long live football test (Spurs v Brighton) of Kae's Low GOP 3 1080p24H mod at 65 MBps.

  • @fatpig

    Yeah, if you use 3.60 for any of this you will bust a lot of things and not be happy ;-)
  • @towi

    Yeah, the only bummer about the 3 GOP hack is that it does affect 1080i. Maybe in a future Ptools Vitaliy can separate them out. With the GH1 we could set GOPs for any format separately including 24P.
  • @jfro

    As to the rollover frames, I'll leave that to you to see if it happens on stock firmware as I have to get back to work at my day job because of a deadline. At least I'm glad the settings are working for you.
  • FWIW… Kae's 24p settings worked fine for me in some preliminary tests even with class 6 cards (!)...
    But GOP3 doesn't work in interlaced mode - the footage shows weird artefacts and some kind of optical pumping.
    As I need 50i/25p frequently I went back to my latest stable GOP6 settings (24p 52/32Mbits & 50i 32/24Mbits, GOP6)
    24p @ 52+32Mbits/GOP6 also looks really great… so for me not a great limitation.
    I would say 1080i @ 32/24Mbits/GOP6 is a HUGE improvement over the unhacked GH2 - many thanks to Vitaly!

    @jfro - as to rollover it's the same here. I can't trim the frames so that I get a fluent motion over the edit; there's a slight offset.
    Don't know how the unhacked GH2 behaves here.

    as to viewing MTS files … honestly I would not trust any player software; better convert to QT through ClipWrap, Neoscene or 5DtoRGB… or import into Avid MC or FCP or so to eye up the files.

  • @kae

    Thanks for your settings. I am exploring them now.

    As for viewing your MTS file, I found MPlayerX to work better than VLC on my Mac.
  • @ kai

    I got 40 minutes on 3 clips with 2 rollovers continuous shooting. Peak at 69000000 mbs but over rates were lower as driving in country and some traffic. I had some sky so overall bit rates weren't sustained that high.

    On the rollover frames, the first 3 frames seem to be the same frame. If you trim, 1, 2, or 3 frames and then butt them to the preceding clip, you still get a little hiccup in play back. On the 40 minutes, there are 3 clips, and there is the 2-3 frame hiccup in each of the 2 rollover clips on the 24p gop3.

    I'm on my laptop, so I can't get to last weeks files, but will try to test today at 60 fps and see if the glitch is there. Maybe someone can test the rollover at a lower frame rate with Gop 3.

    We should also test the original firmware and make sure the duplicate/missing 3 frames aren't there.
  • @bdegazio ⌘-i to have media statistics on VLC !
  • @bdegazio The clip plays fine on my machine. If there is a setting in VLC for you to use your GPU to aid in the decoding that would help. See if there is a build of Media Player Classic for mac or this alternative (http://mplayerosx.sourceforge.net/)

    I've got a Intel Core i7 2600k 3.4Ghz with 16GB of RAM, GTX 580 3GB and the video card decodes the clip just fine. (It had better play back smoothly. I spent enough on this goddamn system!)

    Just to let you know that the clip does play fine. It's not the clip. It's the machine or configuration of it that is hampering smooth playback.

    edit - That's good that it works in VLC!
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