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AVCHD: Extreme settings
  • 278 Replies sorted by
  • @mpgxsvcd

    I can't keep getting into this so I'm just going to stop. You either notice it or you don't. Obviously you don't. And that's fine. There is more of an unfilmic blurring in motion with a longer GOP than there is with a short GOP to my eye. And I am not CLAIMING anything I am telling you what I LIKE. If it's not what you like or notice that's great. I don't have to prove anything to you, nor do I have the energy to try. How can I prove that I LIKE something more than something else? It's like saying you saw two pretty girls but you liked the LOOK of one over the other. Then some idiot says to you - prove it. WTF?? There are plenty of shooters around here who prefer the shorter GOP look. And there are plenty of tech guys around like you who don't see a difference. And that's all fine. I'm so tired of this long/short debate I can't tell you. It's a fricking bore. If some of us want 1, 2, 3 or NO GOP, so what? Do you think I get some revenue off of my opinions of short GOP? I told _you_ specifically ages ago, weeks ago to go shoot a lot of motion with the cam moving and do it twice. Once with 3 GOP and once with 12 or 24 gop. Then playback the ORIGINAL footage (not some crappy Vimeo encoding) on a FULL HD monitor and see if there's a difference for you. And for you, there probably won't be. If you don't want to do it for yourself to clarify it, why should anyone jump through hoops to do it for you?
  • @Kae

    Can you show us one example where a long GOP produces unsatisfactory motion? I would just love to see an example of what you are claiming. You can even exaggerate the GOP. Set it to 60 or something crazy and I am sure it will be easy for you to demonstrate the issue you are experiencing.
  • @Butt
    "hey prefer to try GOP1 - if it is stable: with approximately 32 to 44 Mbit'

    I tried 1 GOP with 3.62 a few times. The footage won't playback at proper cadence even though the card doesn't crash and the I frames were a lot smaller than with 3 GOP - so even though there were more of them at 1 GOP, each I frame does not have the detail that the bigger I frames have. That's why I think 3 GOP is the perfect compromise (2 won't work at all) - 1 big I frame and two B frames that refer forward and backward to big I frames. It would be nice to get the big B frames that 3.62 promises but so far nothing's stable with 3 GOP that looks any better than the 3.61 stuff for motion IMHO. GOP 6 looks darn nice but GOP 12 or 24 is a non-starter with me. I just don't like the look of it for motion though I understand I'm in a minority here.
  • @kae yes, I am sitting tight with 3.61 currently. when 3.62 came out, the universe exploded, and I'm perfectly content to sit back and watch while Mr. V and others put it back together again. In the story of H. Dumpty, I'm probably one of the horses.
  • why more and more MBit?
    it does not improve image

    they prefer to try GOP1 - if it is stable: with approximately 32 to 44 Mbit
  • @kae

    great, thanks! you're the king!
  • @Mads_Junker

    I'm assuming you're referring to an .ini file? If so, import it into ptools 3.61 (not 3.62) create firmware and load it in the cam flashing as per instructions on the forums.
  • @kae

    Just seen you message, been on vacation.Thanks!

    But what do i do with the file? put it in the camera or import it in Ptools? (guess it's a stupid question, sorry for that)
  • @awaterman i'm tempted to do the same, but at the same time i really want to test in EXteli
  • @ivan858 and @kae - I've given up testing at 3.62 as it never seems stable at all, using @kae extreme settings for 3.61 until 3.63 comes out.
  • @kae yea i wish i could delete the file to prevent others from using bad settings =X.

    the 132 24gop has macroblocking on large i frames, haven't had any good experiences with the buffer settings and have been testing this whole weekend.
  • Is anyone having good luck spanning files past 4.29gig with 3.62 and using gop12? If so, what are your settings?
  • @ivan858

    No worries! Crashing is why we're here, right? The day the settings don't crash we can all get back to work:-) I used your settings at 96mbs and could do 5 1/2 minutes on the death chart but it stopped at the 4 gig point and wouldn't span. The footage looked really bad in stream parser. It was high bit rate at first then throttled down horribly as it flat lined. I think it's no joy until 3.63.
  • @kae sorry about that. I did a 4minute test with the death chart with those settings to make sure it would work for you. I guess the death chart is now the not so friendly chart..I had my 132mbs 24gop 4aq x2 buffers crash twice today when they only record at 60mbs..I think its the card because I had write errors before the cam was even hacked. Transcend 10
  • Class10 30MB card guarantees 10MB or 80Mbps minimum write speed and 30MB or 240Mb maximum read speed.

    88Mbps is already pushing the limit.
  • @vvvfmoron

    "That's just what it looks like to me right now."

    Agreed. I think we're just chasing rainbows until the next ptools. I am sticking with the 3.61 65mb extreme 3 gop settings until then. They're bulletproof, at least for me, except for the 10 frame glitch.
  • @ivan858

    Just tried you latest settings. Couldn't film anything for more than 10 seconds on my class ten card. Maybe its my card?
  • I've seen big I, B, and P frames and little ones. I've seen them all close to the same size and I've seen them divergent in size. The one thing I have never seen is one frame that has amazing image quality followed by several frames that don't. That is what we should see if size had anything to do with it. I believe there is still an underlying problem with the codec and the way it USES bitrate. I know Chris and others are trying to tackle that. Until they do I think we are just juggling bitrate without adding quality to the image (other than the obviously but slight improvement of using higher bitrates than stock).

    That's just what it looks like to me right now.
  • The GOP3 settings from 3.61 produced very small Mb size B-frame. @cbrandin's AQ setting dramatically improved B-frame size. Based on my testing, AQ4 setting produced B-frame size about one third of I-frame.

    I like the fatter B-frame. But if B-frame become TOO fat, it lowers Mb size of I-frame. That is what's happening with @ivan858's settings. If all I frames, 154 / 24 = 6.4Mb I-frame. I'm not a fan of GOP1. Never will.

    We know the fix is coming. We hope. When it's fixed, I will probably choose GOP6 instead of GOP3. With vast improvement in B and P frames, it seems GOP3 is overkill. Also GOP6 will have bigger Mb size for I-frame. 88Mbps GOP6 AQ4 could produce 8Mb I-frame. Also a good match with 720p60 GOP6. But there is really no good setting for all cases. Some like GOP3. Some like 6. Some 12. Just pick what you want and know what you get. That's all :)

    I'm kinda excited waiting for the next PTool.
  • @ivan858

    Ok. Will try your settings now. FWIW I don't understand the high low b frame thing at all. When I first came up with the 65Mb exteme settings people bitched that small b frames were bad. Now it looks like small b frames are good??? Why don't we just compromise at BIG I frames only, no b frames or p frames and we'll all be happy ;-)
  • Frankly I don't know crap about how GH2's codec works. I've been plugging numbers. That's all.

    What I'm saying is that such high bandwidth percentage of B-frames tells... it's not a good idea to use low GOP from 3.62 PTool.

    Just like everyone else, I'm waiting for the next PTool. If it has a fix, it would require only 88Mbps to achieve 7Mb I-frame and 2.1Mb B-frame with GOP3 and AQ4.
  • @stonebat i'm not sure how this is all working. why are large B frames bad? i know you posted a ton of info on this in the other thread, but its hard to follow.
    Also, is fallback why i have a negative bitrate in one of the tests?
  • That doesn't look healthy. Healthy B-frame size seems no more than 30% of I-frame size.

    132Mbps case. The codec might have calculated 132/2 = 66Mbps per GOP unit. Since there is not enough bandwidth, fallback cuts it to 50%. Then 33Mbps per GOP unit. 33 * .3 = 10Mbps allocated to two B-frames in one GOP unit. That is average 5Mb per B-frame. The remaining bandwidth goes to I frames.

    154Mbps case. 154/2 = 77. 77 / 2 = 38.5. 38.5 * .3 = 11.55. 11.55 / 2 = average 5.78Mb per B-frame.
  • @kae
    Tests:
    132mbs for 4 minutes, i frame minimum @ 5.6. Max recording time unknown. Records at 1gig a minute.
    average bitrate: -9,675,946??
    132mbs for 20 seconds, i frame minimum @ 5.6.
    average bitrate: 137,487,984

    142mbs for 20 seconds, i frame minimum at 6.06. Cuts out at 1 min and some change
    average bitrate: 147,855,188

    154mbs for 8.3 seconds, i frame minimum 8.08. Cuts out at 8.3 seconds.
    average bitrate: 159,180,648

    I attached the 132mbs settings. Good luck with the tree filming
    132mbs_3gop_4mintest.jpg
    1283 x 688 - 330K
    132bps.jpg
    1276 x 647 - 322K
    142bps.jpg
    1273 x 644 - 319K
    154bps.jpg
    1280 x 800 - 400K
    seti.ini.zip
    338B
  • @B3Guy
    "kae I believe it is here"

    Thanks for pointing me to this discussion. I had totally missed it. Now I understand, although the tech back and forth is dizzying. I must say I don't know if I buy into any of the higher GOP rally for my purposes. If you want to shoot 'motion' picture style with the GH2 (which is all i want to use this for) then the motion quality is the thing. The Gh2 at factory default captured static shots just fine for me, it's the motion that looked like crap. An intra codec is the grail for this cam for me, so 1 GOP would be great but we'll never have it. 2 doesn't work so 3 is the shortest and best compromise. 12 seems so counter-intuitive to accurate motion capture no matter how big the p and i frames are that I'll just wait it out until the next ptools release that let's us get stable lower gop. Has anyone posted a clip with HEAVY motion (in front of camera + moving camera) with new stable 3.62 settings?