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24p25p-NINE - GOP9 Hack for friendly co-existance of 24p and 25p
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  • --- Update 2012-03-02 19:42 --- @cbrandin ---

    This is 94 sec clip of my dog eating a boan. HBR, Lens Lumix 20 mm 1,7. SS 1/50 F1.7 iso 1250

    I also have to thank your for your old settings. The 44 and 66 settings have been my favorites and it was the first settings I was testing with firmware 1.0 and 1.1. And they worked just fine.

    towi_24p25p-NINE_HQ-Matrix_66M44M32 HBR cbrandin_Frames.PNG
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  • @cbrandin Yes I will do that, but have to finish my tests with my current firmware @towi setf. It is evening now so it will not be the same high contrast test, more like my first post from my kitchen:-). I'll try to change to a more challanging subject. I will update this post!

  • @Tomaso

    That's probably right. In a week or so I should have a new version of StreamParser that resonves this.

    There shouldn't be any problems except that many programs will misreport the clip length. Editors shouldn't be a problem as they only use elementary stream timers - which are OK.

    HBR mode can have some strange timstamp issues, which I'm still trying to work out.

    Can you do me a favor? Run a clip with these settings for about 1 minute and post the report. That will help me get a handle on how much the TS timer is skewed.

  • @towi Sorry I must have mixed up my clips. It was ment to be HBR, but I can see that it was wrong. I have now tested your new setg setting of today. It looks promising but clip duration is 11:59 sec and PCR 15:40. Looking at filesize I think the bitrate is closer to 60M. Is that right @cbrandin, and what problems can this give?

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  • @Tomaso

    yes, 66M is correct for 24p

  • @towi This is your settings from yesterday outdoor suny high contrast daylight. Bitrate goes high. If that is correct or not I do not now, listening to @cbrandin about trick mode.

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  • StreamParser is not correct in it's bitrate calculations in some of the above captures (it reports what the files say they are correctly, but what the files say is wrong). The GH2 uses a trick mode where they mess around with some of the timestamps and clocks resulting in inconsistencies with how bitrates are reported. I have a new version coming out that deals with this in a couple of days (it's in test now). This issue only comes up with some of the "extreme" types of settings

  • @towi I have been working on findig settings around 50M, I have found end user only settings that work but I find the ratio between I-P-B frames don't look good. I found your settings and they look very promising. Indoor with fast panning i get as u say near 50M. I will go on testing your settings tomorrow in suny high contrast daylight.

    I certanly hope that your version 2 will work to.

    towi_24p25p-NINE_HQ-Matrix_66M44M HBR_Frames.PNG
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  • @Kihlian

    If the Streamparser info is correct, it actually produces near 50M files in HBR:

    I am just experimenting with different matrixes... let's see what I can come up with. The patch is aimed at max IQ in HBR mode with still images (tableau style work)... while still providing high quality 24p. However I also feel it doesn't jerk... Version 2 will be optimized for motion ... but first I have to learn more on the settings and how to get there...

  • I tryed the 24p25p-NINE, don´t jerks like GOP12. Give me a medium of 36000 Kbps. No problems with sandisk HD video 30mbps. Hope you continue with your work on HBR.

  • @Kihlian

    good to know - thanks! I have not really tested the GOP12-span patch... just made it to have something at hand for spanning. 24p25p-NINE is the patch I am focusing on

  • I made a quik test with the Gop12. The image looks very good in stills but by moving the camera jerks very much in comparison with Spanmybitchup.

  • Thanks for post the comparison. For me the GOP12 is the best when the blacks are pushed. I will now try the Gop12 settings. Report the resoults later.

  • pretty much the same, yes. With Orion looking somewhat compressed (things look different at 24H) and Flowmotion showing some artefacts on edges when you lift the blacks (also things look different at 24H). Differences are negligible, though.

  • So my takeaway from this motionless, low-light test is that for HD still photography of wool fabric, all five HBR patches look pretty much the same, regardless of bitrate and GOP-length?

  • @zzap64


    I've just did a patch comparison at HBRp25 on a static (!) scene at ISO800 in lowlight, tungsten.

    Setting: smooth -2|-2|-1|-2.

    Patches used are: 24p25p-NINE, Sanity (modified), my GOP12-span setting from above, Flowmotion (1.11) and Orion.

    Here's a side by side comparision of the HBR shots assambled in a QT mov; first 4 seconds uncorrected, then pushing the blacks:

    And here are the original MTS files:


    Sanity (modified: FSH=36M / Matrix added):


    Flowmotion (1.11):


    Attached the Streamparser grabs from the scene.

    I'v also attatched a new patch to the first post with new settings for 24p: 24H set to 66M (and 24L to 44M) if you prefer more moderate bitrates for 24p.

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  • @towi - Great settings thanks. Pleased someone is focusing on 25p/30p settings rather than just 24p.

  • @cbrandin I suspect that it's also possible to trigger Trick Mode in FSH and SH modes, and perhaps in 24H mode as well. If these modes are tweaked to prevent Fallback mode from occuring, excessively high bitrate excursions can cause recording to fail suddenly on otherwise uncorrupted streams. My hunch is that forcing the bitrate significantly above the Top Setting in FSH and SH modes triggers Trick Mode, which doubles the effective TS Max Speed and allows the transport stream bitrate to exceed file buffer limits. Hard to confirm, though, since nothing is written to the file.

  • Actually, it looks like trick mode is more complicated than I thought - I have to do some testing/research.

  • @cbrandin What's the minimum duration you'd recommend? I usually shoot for 8 seconds as that makes it easy to estimate bitrate from a glance at the file size.

    Trick Mode is determined by the FH/H Video Bitrate setting which affects both 1080i50 and 720p50 modes. Most Trick Mode settings for those modes will produce 4X in 1080i50 and 2X in 720p50 modes, or 2X in 1080i50 mode only. I had to set it extremely low to produce 4X Trick Mode in both 1080i50 and 720p50 modes, and it required careful fine-tuning.

  • @Lpowell Seven seconds is pretty short - I can see how that might not be long enough. I'll see if I can come up with something, though.

  • @towi Thanks very much. It looks like a trick mode is used for 1080i50, but not 720p50. Weird!

    @driftwood How do you mean Etc mode boosts bitrate, can you post an example? Also, can you post an example of the 80% too? How about when you go up in percentages - is the bitrate cut? You will be able to tell because the Clip and PCR durations will be quite different. Be sure to test with clips at least 30 seconds long, though.

    Looks like I'll have to some tuning to the trick mode calculations.

  • @cbrandin What I've observed is that with certain clips, Stream Parser will report mostly correct times and bitrates in Frames Mode, but will scale the graph incorrectly in Time Mode. In those cases, it also reports an incorrect TS Max Speed in Frames Mode. I haven't seen any cases where it would drop in and out of Trick Mode within a single clip. The clips I've been testing have all been at least 7 seconds long.

  • @cbrandin You'll also find that Etc mode and 80% modes will tax/tack on the bitrate an extra 15-20%.