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Official Low GOP topic, series 5
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  • There is only one way you can force cbr, that is with Q settings to drive up the bitrate and set a frame limit on it. But it needs measuring exactly, else at one end of the scale you get poor Q in fine detail scenes (poor coarseness) and at the other end with less detail scenes you get exceptionally good Q, amazing psnr (not that its a measure of human perceptual quality), and large transform coeffecient percentages with definition but with a much wider range of Q. Perceptually it looks great, but on the charts its strange to see a line of the picture coded with great looking macroblocks and alternate rows coded with poor Q mbs. Somewhere in the middle is always our goal.

  • Although I don't have time for any kind of extended test... using driftwood's latest 100 v3 with ptool 3.64 generated firmware...

    with lens: lumix x 14-45 and lumix 14-140 I could not make it do a write error in any mode HBR,2 4p, 720p or 1080i. This through several zooms and pans with af and ois on.

    Nothing conclusive, but encouraging. I have not checked any image quality or stream parser. All played back. No span test as of yet.

  • *** NEW *** Driftwood Quantum 100 v3b AVC-Intra 100 Matrix (ZERO Q/maximise bitrate Test) This is a bitrate test to maximise the available bitrate using Q. This patch contains the original AVC-Intra matrix.

    Driftwood Quantum 100 v3b - ZERO Q - CBR style - use all bitrate patch - seta.zip
    883B
  • @Driftwood Nick, when it will be available new Quantum X for new Ptool Release? Thanks for your great work (and Vitaliy also, obviously)

  • Quantum X is nearing completion. Just testing matrixes.

  • Thank you Nick.

  • I am seeing a lot of macro blocking in the blue channel with the Quantum 100 v3b AVC-Intra 100 Matrix patch.

    Previously this would have been finer grained noise.

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  • @sebben Interesting, fine tuning matrixes.

  • @sebben What setting - all rec modes ?

  • I'm seeing more noise when testing low ISO GOP 1 108mb and less noise at high ISO.

    Was using 24L 108000000 - Auto Quantizer to 4 - GOP 1

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  • Forget AQ4 for now. Chris maybe working on a new version of that for the future. Please remember fellas, this is early days on the matrix testing. Your feedback is important to me.

  • @driftwood. hey man. thx for the new patch. i'm getting consistent bit rates around 25mbps with 100 v3. about to download v3b to see if that fixes it.

  • I don't know where's the right place to discuss this but the wiki is still empty on it, so I guess I might ask about it here.

    What are these, what are they supposed to do or work and how do I adjust these settings when (as an example and in my very particular case) I change "1080i50 and 1080p24 GOP Size" from 12 to 13?:

    1080p24 GOP Table=1, 3, 0, 0, 8, 0

    1080p24 GOPx2=24 (This one should probably go to 26)

    1080p24 GOPx2 time=48000 (This one should probably to 50000)

  • You can leave those alone, theyre worked out by ptools already. But yes, you can change them, to try and get your patches working with the new version.

  • @driftwood: Hi there, pretty cool that you have made and released Quantum 100 v3, I'm kind off a newbie here, please do excuse my naive questions, but does this new patch (firmware?) records in GOP1 (Intra-frame?) in all video modes? and is it all at 100Mbit may I ask?

    In addition, would there be any problems I would encounter when recording as well like stability? Because I keep hearing of this 'Spanning' at certain bitrate etc. and users saying that the camera just stops recording randomly. These are concerns I have and worried that I would come across them.

    Hope you dont mind me :)

  • All intra except 720. 720 will not work on GOP1.

  • @driftwood v3b fixes 25mbps issue. Getting correct rates at 24H, L, and HBR (showing up around 80mbps).

  • You can change Iq and Q =16 or 18 to get inbetween bitrates.

  • @driftwood Ohhh okay, how comes it doesnt work on 720p??? that's very strange.

    Also, how would one install this? is it possible to revert back to the original factory settings?

  • The main new update with the new ptools is that it entitles you to be able to insert customised Quant scaling metrics in the scaling Matrix sections. This is pretty much a black art and I'm working on some interesting matrixes for Short GOP and for that matter Long GOP for new upandcoming patches. A lot of the calculations are now performed by Ptools automatically (even if you dont check certain settings). Chris (cbrandin) will be releasing info, spreadsheet parameter makers etc.. either on the wiki or on his threads over the forthcoming days plus an updated version of his 44/66M patches with some excellent matrixes of his creation. In the meantime I am working on a Quantum X matrix which is my primemost concern.

  • @GH2_fan Download ptools364 to new folder, copy the original latest firmware from Panasonic (v1.1) and put that into the same folder, copy any user patches to the same folder. Now run ptools and load up v1.1, viola everything is there. If you don't want to use ANY patches uncheck everything (if youve checked anything - you may want to keep the basic 30 min limit overide and high iso max so keep them checked) and save the .bin again and youre back to vanilla v1.1.

  • @GH2_fan 720p is very strange, very tempormental. GOP1 (INTRA) just about works for 3 seconds on 720p60 and around 8 seconds on 720p50. Ive tried many times to battle with the GH2 on this mode - but it just doesnt like it. Now whether in future VK can sort that out - who knows?! On the subject of 720, you can get B frames to work (but you have to record on a different rec mode first - like 1080 - before recording a 720p file). Even GOP3 for 720 is problematic. Thats why you wont see any patches successfully recording 720 below GOP6. Hope that helps.

  • @driftwood : Thanks, if PTTools does it in my behalf I'll just leave them, just one more thing, is the GOP table structure anything like this:

    I-frames-even, #P-frames-even, #P-frames-odd, I-frames-odd, #B-frames-even, #B-frames-odd ?

    (sorry about text size, I can't figure what happened)

  • @driftwood Thank you very much, that wsa very informative and very helpful as well! It is indeed very strange that 720p cannot accept your patch for doing Intra-frame recording, I always thought technically it should, also due to the fact that it's 720p resolution, thus not putting pressure on the bandwidth. Very odd.

    I also would like to ask, because of the different recording modes in 24p i.e. 24H (High bitrate), 24L (Low bitrate) and 50i i.e. FSH (High bitrate and FH (Low bitrate) , does your Quantum 100 technically records 100Mbit in both? OR 50Mbit in the lower bitrate modes like in your previous Quantum patch?

  • @GH2_fan 100 in 24H & 50 in 24L