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Official Low GOP topic
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  • stoneystoney
    Frankly I'm quite happy with 66Mbps 12GOP and 110Mbps 3GOP. I'm sure that curious people will fill up the vacuum ;)
  • MihuelMihuel
    @cbrandin
    Thanks :-)
  • cbrandincbrandin
    I think @stonebat has it close to right. I'm just guessing according to theoretical criteria - you'll have to test them. In some cases the AQ may need to be lowered a little.

    Chris
  • MihuelMihuel
    @cbrandin
    Do you have any suggestions for 6GOP and 88 or 110Mbits? Unfortunately, my knowledge is, at least, enough so that I can handle myself.
  • MihuelMihuel
    ok, let's wait for the opinion of the wiser of us on this issue :-)
  • stoneystoney
    @cbrandin would know a multiplier for the case.
  • MihuelMihuel
    @stonebat
    I tried GOP6, AQ3 and FL and FBs x1, 5 Charter does not withstood and the Stream Parser showed a few seconds I = P = B
  • stoneystoney
    Interesting. Thanks Chris.

    So we have a matrix?

    GOP12 AQ4 for 44, 66, 88Mbps
    GOP6 AQ3 for 66, 88, 110Mbps
    GOP3 AQ2 for 88, 110, 132Mbps
    GOP1 AQ1 for 110, 132, 154Mbps

    The lower GOP, the higher bitrate range, the lower AQ.

    If AQ and multiplier are set for each mode, it's basically 2-d matrix of Mbps and GOP.
  • driftwooddriftwood
    @cbrandin Have you worked out a stable-ish multiplier for AQ3 at 132mbps?

    @stonebat elecard buffer analysis verifys the clipping and where it will fail.

    edit: still testing my buffer theory.
  • cbrandincbrandin
    For GOP 6 I would estimate that you could go to AQ3 at any bitrate. With GOP1 I think it's AQ 1-2 no matter the bitrate. This is because AQ is automatically scaled according to bitrate.

    Chris
  • stoneystoney
    @Mihuel never mind :)

    @cbrandin
    How do we verify the clipping?

    What about GOP6 for 66Mbps and 88Mbps? AQ3 is the practical limit?
  • MihuelMihuel
    @cbrandin
    My jaw dropped to the floor and I already have :-)
  • MihuelMihuel
    @stonebat
    I think so, but you know how a woman is pregnant. Maybe it is a small elephant? ;)
  • stoneystoney
    Orly? Ok. Back to AQ2~!~!
  • stoneystoney
    Mihuel, is your girlfriend a human? :) The B-frames are abnormally high.
  • cbrandincbrandin
    When you lower frame limit it will end up raising the effective QP value to accommodate the lower bandwidth allocated to I frames and do other strange things. It's sort of like clipping - not really a good thing. Better to leave frame limit a little higher and lower AQ until it works. According to my calculations (based in part on your feedback), the ideal AQ value for GOP3 at 100Mb would be between 1 and 2. It seems that 2 works pretty well, 3 is clearly too high according to my latest math. With GOP1, you probably want to use AQ1.

    Chris
  • MihuelMihuel
    @drifwood
    Ok, good idea ( better then mine ) ;)
  • driftwooddriftwood
    @Mihuel download Stonebat's110 aq3 (setj) and load it and confirm a test matches his with streamparser
  • MihuelMihuel
    @driftwood
    Unfortunately stream parser several times showed the same thing. Maybe this card? Maybe this is my model of camera?
    When I changed FBs and Fl to 1.3 ....
    Hmmm, I think I'm doing something wrong. Anyone can help me ?
    110Mbits GOP3 AQ3 Fb Fl X1.30.JPG
    1288 x 669 - 148K
  • MihuelMihuel
    @driftwood
    ok, I will try again , thanks for advise :)
    P.S. I'm loading patch with 1.3 FBs and Fl right now .... so after this ....
  • driftwooddriftwood
    @Mihuel that doent look right, close streamparser reopen it and reopen that same file.
  • BraamokievBraamokiev
    Thanks to:

    @Mihuel
    @Stonebat
    @Drifwood
    @Stip
    @Stray

    And special thanks for Vitaliy!

    I wait the best Setting 100mbs
    ;-)
  • MihuelMihuel
    @stonebat
    This is a graph from settings 110Mbits, GOP3, AQ3 and 1.37 on FBs anf Fl. This was simple shot of my girlfriend.
    110Mbits GOP3 AQ3 Fb Fl X1.39.JPG
    1288 x 670 - 149K
  • cosimo_bullocosimo_bullo
    @ stonebat

    "The h setting is 110Mbps, GOP3, AQ2, X1.5 on FBs and FL. The j setting is 110Mbps, GOP3, AQ3, X1.39 on FBs and FL. Both worked. The attached diagram is from the j setting. My gut feeling is that... the B-frame seems little too big. Or is that a typical behavior from AQ3 setting?"

    I think it is typical of AQ3 and 4... and to my mind it's a good thing, those big b-frames, especially with non moving shots. Going to test your latest right now.
  • stoneystoney
    a simple tweak on @driftwood's settings ;)
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