Personal View site logo
GH2 - Modular settings - anyone interested?
  • 45 Replies sorted by
  • tychotycho

    I am following this thread avidly even though not commenting, this is one of the most interesting discussions on PV (for me at least) and even if there is a lack of contribution from others that does not mean this is not a hugely significant topic and should be considered eventually as a FAQ topic as "how does one mix and match settings/ what other factors will one setting screw up if changed/best solid modular plug and play settings"

  • duartixduartix

    I get your point @Vitaliy, but I was giving out information to @Chhatrapal & @mickos who are in similar grounds to mine and that might interest other members.

    This information is coming out several hours apart so I guess it didn't make sense to keep updating the same post, as those changes might escape someone who is following the thread.

    As for the last one line comment, you are right, I was talking to myself but, you know, I may die unexpectedly today and no one else might think of trying it for another 2 months...

    I'll try to hold the horses from now on.

  • Vitaliy_KiselevVitaliy_Kiselev

    @duartix

    I really suggest to stop making topic into a mess and talking to yourself.

  • duartixduartix

    Well, another big reason to ditch MJPEG: http://sonnati.wordpress.com/2010/10/19/h-264-for-image-compression/

  • duartixduartix

    Stop the PRESS!!! There is a 60i independent GOP setting!

  • duartixduartix

    Well, @Chhatrapal the test is done...

    Amazingly there is a MJPEG 2048x864 mode in Quantum 100-50 that has a very very fine edge on AVCHD for horizontal resolution. However there's a problem I spotted as soon as I put the camera in MJPEG mode: recording time! As it was, the camera would only record for ~2min! :O

    My first thought was... "What kind of bitrate hell is going on in this mode???"

    The second was... "How on Earth is it that my Samsung 16MB (benchmarked at 15MB/s) is still holding on ???"

    Then it hit me! "Spanning!" MJPEG doesn't span! And to add insult to injury, the file limit is probably 2GB! :(

    So what about my first plans? I went ahead, dropped the frame rate from 30fps to 2fps and got 15x the duration. I also took the quantizer values and tables and doubled them (which is still around half the default values and twice the quality). Another 2x gain.

    Now the camera says it will record 56min on MJPEG which isn't so bad, but man, I have AVCHD timelapses that spanned over 15GB for nearly 2h on Full Intra (the 13 GOP trick)!!!

    I've just tried Quantum 100 with 2fps AVCHD and it predicts 26min so Quantum 50 should still give you nearly one hour on 16GB. The thing is that even though it's skipping about 1 and 2 frames alternatively, it's still 50i so you have around 10x more Intra Frames than needed because they'll be identical at 2fps... :(

    If you are really serious about long 2fps timelapses, sacrificing either the 24p or 50i is the way to go. You'll probably get 10x more duration because you can enlarge the GOP by that much and (for example decrease the L bitrate by the same amount) ending up with roughly the same quality. And considering that typical timelapses on tripods are by nature easily compressible, you might even consider giving up Full Intra (at every 1/2s) and use very long GOPS. If the light isn't changing, I'm sure the P frames can keep the quality going strong with marginal use of bitrate and in no time there will be an Ultra Long Recording patch set that tries to run for 24h if the camera doesn't burn first... :)

  • duartixduartix

    @Chhatrapal: Most timelapses won't challenge the bitrate. The idea is the opposite in fact, saving bitrate in order to get a bigger time frame on the card.

    My first idea (and that's because I've learned recently that many settings interplay between modes) is to start with Quantum 100, pick one of the FHD modes and just cap the bitrate, set GOP to 13 (because I'll be using 1/2s shutter speed) and not touch anything else so I don't break the other modes.

    Video Bitrate FSH/SH=12000000

    1080i50 GOP Size=13

    Video Bitrate will essentially define how long you will be able to record and GOP 13 serves two objectives:

    1) Having an I frame every 1/2s on the frames that I'll be keeping (don't ask me why it's GOP 13 and not GOP 12, but from the 2fps thread and a few quick tests of my own, I found that it is how it works).

    2) Spend as little bitrate as possible on frames to discard (and this is also guaranteed because the 1/2s shutter implies that everything (except for the I frames) has no recorded differences and thus is efficiently encoded using P/B frames). From memory I'd say the waste will take around 10-15% of the footage.

    But, and now this is the BIG BUT, since it implies loosing on of the big 1080p modes, I'll have to do a serious IQ comparison with MJPEG (which I don't use for anything right now) but for which (since you can drop MJPEG frame rate to 2fps) there is no waste.

  • ChhatrapalChhatrapal

    @duartix What settings will u change say for Quantum 100 ... what it will affect 24H/L,720p/60/50. Btw i am also not very happy with MPEG time lapse too

  • duartixduartix

    Thanks @mickos. I was about to post asking precisely for what you've done! :) Yet, I believe AVCHD with GOP13 settings is the right tool for timelapses. I've flattened batteries on it and it's amazing (I'm using 1/2s shutter exclusively). It's nearing 2h on a 16GB and I would get even more with a bigger card and continuous juice. I really want the best resolution I can get and I suspect MJPEG won't give us that. :( But that means one of the FHD modes must be sacrificed... :(

  • mickosmickos

    Along those lines @Chhatrapal I've tried combining the very latest Quantum 100 with Timelapser and made a file - it works great for 24p H and 24p L (100Mb/s and 50Mb/s) and the AVCHD 720p 60fps modes (SH and H). And timelapser. But not so good for the AVCHD 1080i 30fps modes, though I wasn't really focused on them. But having 24p and a 60fps slow-mo option and timelapse is the objective. Rec times on a 32Gb card are 41 mins for 24pH, 1h22mins for 24L and 52mins for 720p SH 60fps.

    setg.zip
    849B
  • ChhatrapalChhatrapal

    Lets Say ... I want combine latest Quantum V9b as i am fine even if doesnt span on my 32GB/30MB/S Card In 24 H mode ... and then i am looking for reliable 24L mode with spanning + MPEG settings for time lapse (I noticed quantum changes MPEG settings reducing MPEG recording time,not ideal for time lapse,neither it increase quality)+72060fps w/wo spanning. So if i load Quantum V9b in Ptool and then tweak settings for 24L (100 mb/s spanning for me) and change MPEG settings mentioned by GH13timelapser and change 72060fps settings according Quantum 100 ... Will it work? ... What are risks involved?

  • duartixduartix

    I see, but my problem right now is that the latest patch sets from Driftwood are ultra bitrate spenders and require über expensive memory cards... I'd prefer to have a more conservative patch that doesn't fill my Samsung 16GB (15MBps) SD before I can say Mississipi. Should I go back to SpanMyBitchUp (from November 2011)?

  • MeierhansMeierhans

    @LPowell I ment: Dig a bit into Ptools and the INI files and you will soon be able to combine the the AVCHD and MJPEG settings of your choice. I am quite aware of the heavy tweaking you guys are doing, so I do not touch the settings, only combine the MJPEG Timelapse settings with newest Driftwood for now. :)

  • LPowellLPowell

    @Meierhans If you modify only the "Patches for end users" and stay below 100Mbps, then yes, you can experiment without much hazard. High levels of AQ, however, can provoke the encoder into sporatic Fall Back Mode GOPs, which will seriously degrade image quality. Since the camera will continue to record during Fall Back Mode, the only way to detect this pitfall is to examine sample video streams with a tool like cbrandin's Stream Parser.

  • MeierhansMeierhans

    I thought it was in the mjpeg timelapse thread, but could not find it. Take a look at the settings in ptools, change some, save them, look inside the INI file. You will see its not that hard to combine settings.

    edit: Well, this would leave us with two possible modules only, AVCHD and MJPEG. That´s not really worth the effort.

  • LPowellLPowell

    Although 1080p24 and 720p60 patch settings are separate, the 1080i60 video modes share some patches with 1080p24 modes and some with 720p60 modes. If you attempted to combine 1080p24 and 720p60 patches from different sources, you'd most likely end up with dysfunctional 1080i60 modes. While this may not be a problem for those who have no use for 1080i, it's not a good way to promote the overall reliability of GH2 hacks.

  • duartixduartix

    @Meierhans : That's great! :) Where can I find them?

  • MeierhansMeierhans

    People are already doing this. There is patches that only alter the MJPEG modes and are ment to be loaded after you loaded another settings file. I believe due to the crossplay we could only have 3 modules: 24p, 50&60p/i and MJPEG.

  • duartixduartix

    Cheers @balazer!

    Thanks for clearing that, but I still see an advantage in having patch settings published in modules.

    First, those who don't know would clearly get to see which settings are shared and which make up and belong in which modes.

    Second, we would have the power to mix them as we wished.

  • balazerbalazer

    PTool patch settings are already modular: each patch modifies one little part of the firmware image. In many cases it is possible to have different patch settings for different modes, e.g. AVCHD 720p and 1080p. But some patch settings are shared by different modes, e.g. the frame limits for 24H and 24L. That's just the way the firmware is designed. There's no getting around that without rewriting the firmware.

Add a Comment