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Official Low GOP topic, series 2
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  • driftwooddriftwood
    @Gabel Im doing a roundup of 32 annd 64M 'top' reputable cards this weekend - hopefully they'll all be here by then!
  • driftwooddriftwood
    @Stray Ive got 3 GOP & 6 GOP patches of all my settings which Ill stick up soon. Just trying to finish 1GOP.
  • bwhitzbwhitz
    For 60fps 720p... I've seen artifacting on anything lower than 6GOP...
  • driftwooddriftwood
    @bwhitz 60p is a bitch. I'm still fighting getting the right setting. Have you tried my new ver2 720p50?
  • driftwooddriftwood
    Quick test of GOP1 720p50.
  • BotvinicBotvinic
    @driftwood
    >>Is your card ok at 1080p24 176M GOP1?

    Yes, everything is fine, no artifacts. But when shooting trees GH2 dies.
  • driftwooddriftwood
    @Botvinic did you check for artefacts on 720p ver2? can you also try 1080i50 too? I'll keep messing with settings. Damn trees... Why does everyone wanna slowmo trees all the time... TREEES... down on my knees with bloody trees.... thanks for testing.
  • driftwooddriftwood
    @Botvinic what sd card you running?
  • BotvinicBotvinic
    720 50p ver2 - artifacts.
    1080 50i ver2 - artifacts.

    : (

    >> Why does everyone wanna slowmo trees all the time ...

    Haha! I do not want trees in slowmo. I need 50-100 Mbps gop6 Aq2 without artifacts :)))
  • GabelGabel
    @driftwood: Perfect! I won't be ordering after the weekend anyway. I need one that won't die. And in my case I need something that handles things like trees. A lot of work I do is second unit shooting, which often involves shots of nature...
  • BotvinicBotvinic
    I do not think the blame card. I have taken your settings, set gop12 and 32 Mbps 720 50p, and artifacts have been! Can be a bad GH2? :)

    This
    silicon_power_sdhc_card_32gb_class_10.jpg
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  • driftwooddriftwood
    Can't blame the GH2. Don't like the look of that card though :-( Before I go off improving tell me the artefacts - bad macroblocking?
    Update: Your card reviewed states Write 11~15MB = not good enough!
  • BotvinicBotvinic
    Yes, speed is low. But for some reason my settings to 50 Mbps and GOP24 work, but your settings (my modification of 32 Mbps and GOP12) give the artifacts? And why 24p to 100 Mbps GOP1 works without artifacts?

    >>bad macroblocking?
    Well, I guess. The screenshot shows all

    http://www.personal-view.com/talks/discussion/comment/16419#Comment_16419
  • StrayStray
    @driftwood cool. look forward to seeing the GOP 3 & GOP 6 versions. Someone else has asked too, but does anyone now the max bitrate of the GH2s SD card bus ? Cos I think in some cases with these 176M patches, when shooting something extremely detailed with high motion (shots where we actually hit close to the 176M limit), that it may be failing down to the bus speed rather than the card type.

    @bkmcwd Running your patch at AQ1 it passed shooting those trees in strong window perfectly. I could shoot it all day, the results are really good too. Mind you its average bitrate was only around 133M. In a lower light, lower detailed shot it dropped to around 42M, which is pretty dramatic really.
    176M GOP3 AQ1 high motion and detail.png
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  • PerryWilsonPerryWilson
    @TrackZillas what does x264 encoder work with or is it a stand alone unit? Im on Mac too BTW
  • PerryWilsonPerryWilson
    what are you guys talking about when you say 80% or 200% speed in camera for 60p?
  • driftwooddriftwood
    @Botvinic
    '...for some reason my settings to 50 Mbps and GOP24 work, but your settings (my modification of 32 Mbps and GOP12) give the artifacts?'
    Botvinic, you can't simply adapt my settings by putting a different bitrate/GOP - theyre not set up that way. Each has to be tested. Of course my settings wont work at 32m! These patches of mine are refined for GOP1 176M or 132M GOP3 AQ2 respectively!
  • driftwooddriftwood
    @Stray At 265M bitrate for GOP1 the buffer analysis reported summit like 187M death charts being employed so its well beyond! But stability was the issue. :-)
  • StrayStray
    @driftwood Good to know, but its hard to say if stability could be related to the bus bandwidth I feel. But yep, if its going to fail elegantly with an 'unable to write' when it hits the speed limit of the bus, rather than being unstable, then we know that we can push it to 187M at least. So, given those assumptions, any write problems with a stream hitting under 187M are going to be card related.

    Edit: I don't know if its that clear cut with card write errors though, I mean we've all seen them with cards running reasonably low bitrate interlaced 50i or 60i settings when far higher bitrate progressive footage works perfectly well.
  • ignatiusignatius
    Hi Nick,

    I stupidly just used your 176 V2 on a job before testing it thoroughly (I have been using a transcend 32GB class 10 on all tried patches)

    Footage looks great, but playback in camera was an issue. It was the same background/level of detail in all shots, just switching out the people. The clips were playing back in camera, but then I got read/write speed errors and after a hard reset (battery and card taken out) 'no valid picture to display'. However, I'm currently loading the footage to my desktop and I was able to watch the footage back in windows media player on a laptop via an internal card reader (didn't get a chance to see if audio was in sync, but hopefully it is because I will be referencing it when I sync up audio recorded to zoom)

    Hopefully all will be good and yes I'm a berk for not testing/not using a better card.

    Cheers for all your work, the best footage I've gotten of the gh2 has come from your patches. Also thanks to all the other contributors/testers

    All the best
    Sam






  • driftwooddriftwood
    Maybe @Vitaliy_Kiselev knows the GH2's SD card bus bandwidth max?
  • driftwooddriftwood
    @ignatius They should be fine. Strangely, Ive found in camera playback comes back after a turn off and good recording.
  • StrayStray
    @ignatius yeah, I've noticed the same thing as driftwood said clearing the in camera playback too.
  • PerryWilsonPerryWilson
    V3 (QuantMeBaby) has no playback issues for me... Extreme 45mbit/s cards
  • TrackZillasTrackZillas
    @PerryWilson The X264 can be used with any transcodable softwares like MpegStreamclip, or 5dtoRGB ect.. it just bypasses quicktime encode and uses it's own decode engine which is way better than quicktimes. I was digging a little bit more about it the only downside is that it does not integrate with Premiere Pro CS5. For better quality exports I'm thinking on switching my system to windows and getting a license for MainConcept Encoder 5.1 I've heard it's well worth it Perry..
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