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Official Low GOP topic
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  • @atticusd - Many thanks for the lucid explanation. Will attempt that first thing tomorrow! Thanks again
  • @jamesgh2 Yeah you're absolutely right -- I can't tell you how much canon footage is on the air (or at least from my experience) -- part of it is that usually you're allowed at least 10 percent non-true hd, but a bigger part of it from my experience is the comfort level of post supervisors and online houses with the footage quality. EDLs can always be massaged, but that's someone else's call -- but getting it to a close as possible to that 50mb 422 makes that easier, especially as the big complaint of online houses with 7/5d footage is lack of latitude in colour correct, in part because of the canon super saturated look, and in part bit rate.

    Anyway, my interest is getting it the highest quality possible, and as filmic as possible, without sacrificing too much in maximum record time of one clip. I love dslr footage, in part because when you're missing something you can just go out and shoot it and get something that looks so much better than archive; also because of the portability, inexpensiveness, etc.... but also have been in situations where I've had to pull back the dslr footage because of quality issues, even though what was shot was more useful for the edit.

    So yeah, gh2 as an A cam, not happening, but gh2 as the ultimate b-cam/pickup cam -- that's my dream. So anyway, if anyone knows some stable 50 mbps gop3 settings (or close that I can play with) would love to know.
  • Watch ch5 in the UK and enjoy GoPro as the main footage with 2 million+ viewers go figure :) among others.
  • @svart

    "What I meant was that even though the bitrate is much higher, the quality difference is not in equal ratio."

    Understood. But I'm not so sure that the 65m 24p settings are compromising anything else, so if there's any improvement in image at all I don't know why we wouldn't use them, except of course in storage requirements.

    BTW: Are you able to get the high data rate 1080 24P GOP 3 clips to span? Mine write 4 gigs perfectly and stop. Is there a setting on the camera to force it to span or are the settings just breaking the ability to do it?
  • @JDN
    "Work in TV and hoping to get the GH2 over the 50 mbps compliance standards of most major broadcasters"

    If you're talking about a 50 mbps average stream not even the 65M mode will get you there consistently with 'normal' footage. Most normal stuff for me is laying down between 36-48 with these settings.
  • @Angry_C @svart @butt

    Been trying to combine the pretty stable 65M extreme 1080 24 3 GOP settings WITH stable settings for the other modes. Using the 'double' the high/low settings logic that worked for the 65M settings and applying it to 720p and 1080i modes while capping FSH to 42m I'm getting some damn stable 35 Mb/s settings for 720p and 1080i modes at 12 GOP. I'm doing 7 minutes on the death chart in these other modes without a hiccup - playback is fine in cam and desktop. Since you guys had the most problems with the other modes in my settings, could you try and break this in 720P and 1080i when you can? (The 65M 1080 24p stays the same as above and 1080i/50 is still 3 GOP by necessity - no blips on any mode except 24P - reformat if you can )

    Thanks.
    KAE65M1080_24P_3GOPand42M720_1080i_12GOP.zip
    511B
  • I see that the blip the first GOP, may have something to do with the P frame appearing. Stabilizes with IBB afterwards but the first has IPBB, maybe it is an uncompleted chain of... what GOP? standard 12?
    EDIT; P frame is in wrong position, It should be of course after two B's.

    So, why only B frames are allowed? What's so good about them? Oh, i see, no Motion Compensation right? So when you hit pause in a player it only stops at I or P frame right? P being formed then with the what? What's so bad about P frames?

    A feeling I have with those low gop patches is that image is more dense, like it's density is more than without the hack.

    100mb I frames with death chart wow! Small B frames though, I wonder with a normal situation... Ok i go record some stuff.
  • @kae
    I'm going to test your settings for 720p50 as soon as i can
  • @kae
    sorry - I try to time settings for 720/60p with B-frames. . .
  • @kai
    I still get write errors with your settings. I have 4 cards and they all get the error.

    Yesterday, I tweaked your settings and used the 76% of top rate for the low rate. I did not get one card write error doing that. I posted earlier some postings I found about the76% or higher issue and it made your settings work without card write errors for me when I bumped up the lower rates to within 76%.

    I got the highest bit rates on my videos shooting your settings from last weekend (24p only settings) . I'm not getting the same upper numbers anymore with your settings or mine (I've moved my upper numbers all over to no avail). Not sure why that is because I have tried your last weekend settings again, and still don't get the high mbs's. that I got last sunday shooting on the waterfront. I know seem to be around 47,500,000 bps on your settings for 24p as well as mine which is set lower. Sunday I was getting 53,512,260 bps on your weekend setting.

    I have attached a readout and settings for what I tried today. The read out is from driving around with camera in my car, but it's the same I'm get shooting any complicated footage. Coming back from a meeting in 24p mode, I got 14 minutes on a 4gb file and it successfully rolled over to 2.5gb and about 8 + more minutes.
    Again, no card write errors.

    On a side note, I am freaking out a bit as I just watched some footage and am noting a subtle strobing effect when the frame contain lots of shadow and low midtone areas. Checked my Canon 24p footage & I'm not seeing the same strobing so it's not the TV. I don't get the strobing on the GH2 in 60. I have a shot where a row of tall bushes are on the side and they are dense and darker than the the rest of the frame. When the whole frame is lit, I'm not noticing the strobing. More testing to do and will shoot the same with Canon at 24p and see if it's there.

    Back to the card write errors and the 75% idea for low bit rates compared to upper bit rates. Here are the settings I used yesterday & today. (I have also run 60p and 1080i, but not extensively tested these listed settings without card write or other issues).

    [Information]
    Comment=kae settingworking with top bottom 58mbs
    SD_Card=Any
    Camera=GH2 v1.0E
    [Settings]
    Version increment=2
    30min limit removal=Checked
    PAL<->NTSC Menu=Checked
    Video Bitrate FSH/SH=42000000
    Video Bitrate FH/H=35000000
    Video Bitrate 24H=58000000
    Video Bitrate 24L=44080000
    720p60 GOP Size=10
    1080i50 and 1080p24 GOP Size=3
    1080i60 GOP Size=6
    Video Bitrate 24H ADD=58000000
    Overall Bitrate=58000000
    Overall Bitrate 2=44080000
    Video buffer=0x3000000
    Video buffer 24p=0x3600000
    1080p24 High Top Setting=58000
    1080p24 High Bottom Setting=29692
    1080p24 Low Top Setting=44080
    1080p24 Low Bottom Setting=22566

    Attached file is from the car ride.
    typpical 24p read for these settings.jpg
    1300 x 757 - 197K
  • @jfro
    "I still get write errors with your settings."

    What you posted in your text file, aren't my last settings, so I don't know exactly what you've been using. I haven't been able to get any rock solid stability at all with GOPs under 12 yet for the 720P or 1080i modes (besides 1080i/50). But I think your 'car drive' test is very valid as none of us are doing anything that severe. I'll try your 76% low theory today with the last combo settings I posted above your post and see if it helps. But I haven't been getting any write errors at all with those settings so far, so I might not be able to uncover anything. Did you notice if the B frames were bigger with the 76% low settings rather than just the doubling? How did you come up with the top settings? Arbitrary? A multiplier?
  • If I want to test stuff comparing hacked vs unhacked, and I don't want to move camera at all so the scene stays the same, which is the easiest way to do this? use 2 cards-1 with original and 2nd with hacked and change card and load each time right? Also, a few noob questions for a noob first-timer : when loading kae's settings version increment from 1 becomes 2, so I saved firmware like that without adding a 0(is this insignificant?). Whenever I want to load new settings and stuff, do I need to tinker with anything in version increment? is it supposed to stay at 2 now always, do I need to change anything each time I save new firmware? lastly, is it ok to put firmware on card, load new firmware, then format the same card and start shooting on the same card?
  • the extreme settings are not well
    they do not is not stable - that's why there not so good
    we should remain in a stable setting lowGop
  • @kae
    The settings I posted are my using your base and putting in new encoding numbers. I basically cut down your top a bit, and then used 76% of the top to figure out the lower rate whenever possible as I read a post or two by Vitaliy stating that the lower number should be 76% or higher ration. When I did that with your settings from Monday/Tuesday, I quit getting the write errors in the 24p mode. I have not extensively tested the other modes, but I've done some 60p driving around and so far so goo. I'm heading out for a family dinner and will throw the cam on the dash board in 60p and report back in a few hours. I don't anticipate any problem, but it's a 15 minute drive so will get a little feedback.

    Can somebody explain to me what the 24 hightop, highbottom, lowtop, & lowbottom settings are/do?
  • @Kai
    I get the write errors in 24p pretty frequently from you settings since you added the other 60p/ 1080i settings. I did not get write errors on you 24p only settings last weekend. The settings I get errors from are from the last 2-3 days. I used the one you put up this AM and got write errors. I have 4 class 10 cards so it's not the cards as they have been working fine in the GH1 & 2.
  • >Does anybody know if their is a way to display or export all the settings in ptools. I'd like to make an excel or word doc of the settings I'm playing with. It's a lot of clicking to check and recheck all the different settings.
    @jfro
    As I wrote before:
    >I've started a Google Docs spreadsheet for testing results. Maybe something like this will help :
    https://spreadsheets.google.com/spreadsheet/viewform?formkey=dEgzTkhsZGRqdWZZdk5raWFxbmtobXc6MQ
    So I agree with you about a structured documentation process. Do try to post your results on my own spreadsheet: I'll amend the spreadsheet to suit you. Or else, please post your own.
    The ultimate solution would be a full wiki with peer control. This could become a real manual for the GH2 Stalin.
  • @stefanos

    When you save the firmware it has to be in the 'GH2__Vxx.bin' where 'xx' is any number you want. Just make sure the different firmwares you make have different numbers. It's my understanding the cam does not care what the number is when 'version increment' is checked. E.G., I have loaed GH2__96.bin and a minute later loaded GH2__21.bin. Both loaded fine.
  • @Butt

    Weird. For me they are totally stable when the other modes are set to GOP12. And the 65M 1080 24P has been bulletproof. So I guess, I'm testing in ways that don't break it. What settings are the most 'stable' for you and what is the maximum 'stable' bitrate you're getting in 1080 24P 3 GOP mode?
  • @jfro

    Well, looks like you're making progress. I had stability issues with the Gh2 when trying to set the other modes lower than GOP 12. So this is what I am using and get 35 mb/s stable until someone can show me how to get a higher data rate. Again, I don't have any need for the other modes so I'm content at 35Mb/s. What I do use is the 65M, so if that is unstable for you (and it's totally stable for me), you're on the right track by lowering the settings. The high/low settings must be explained by Vitaliy. I just doubled them by chance and it worked for me.
  • Ehi kae with your setting in 24H i become only 35M and not 60M, maybe VLC read the bitrate wrong?
    On a Mac i can't find any program to read correct video rate.

    Sometimes the camera don't load the new FW also if on display all go fine, i tested with version increment by 2 and i see ever 1.0, mhhmhmhhhhhh.......
  • @kae

    got 2 long clips in the 60p mode off my posted setting from earlier today driving to and from dinner.. The first clip was a touch under 4gb and was in the mid 40's for data rate. . The 2n clip was a little higher as it was darker and the iso was up at 2500. The rollover worked as did my earlier 2 driving modes at 24p. I have run 4 long clips driving today, 3 with rollovers. Successful. No glitches. Only issue is the bad frames at the begging of the clip which is no big deal on the beginning but a ball breaker on the rollover.

    I had grabbed the conversation on the 76% and posted it on the 27th. It's near the top of this page (7). Just do a 76% search in your browser.
  • @Ulisse

    The 60m bit rate is MAX bitrate so on normal scenes you should be seeing 35-45 mb/s, so your footage is ok.

    @jfro
    This is good news on the high data rate 60P I will have to test this. What kind of data rates are you getting on your stable 24P settings that will span on the card? Your settings seem pretty stable now can you attach the ini?
  • @kae

    I can't upload .ini the file. I get (seta.ini) uploaded file type is not allowed when I try to upload it. Do I need special permission or something?

    On my drive arounds today and all other test with these settings I get around 47,400,000 mbs @ 24p. @60p, max was 45,000,000 mbs. I'd like to try to get back up to the 54,000,000 mbs on 24p that I got last sunday on your 24p only settings. I have not been successful even when reloading your old settings. Kind of perplexing.

    Have attached the 24p and 60p g13parse settngs from today. Again, I was successful with both 24p and 60p but 2nd file after the first 4gb was bad for the first few bad frames as is in all clips.
    24p rollover drive around.jpg
    1297 x 683 - 183K
    60p rollover drive around.jpg
    1297 x 683 - 182K
  • @jfro
    @Ulisse

    Please remove INI text from message body, use attachments.
    To attach ini just zip it or rename to txt.
  • @jfro

    Unless you're shooting the exact same subject matter, you'll never get the same data rate. This is why I test with the death chart. It will consistently give 64mb/s shooting that chart with the 65m settings. using the 60m settings it's roughly 59. 47Mb/s on normal footage is pretty dang good, so you probably we're just shooting more detailed things in your previous outing. I am going to play with your settings in the morning if you upload the zip per Vitaliy's instruction.
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