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Official Low GOP topic, series 2
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  • IDK if it is the MOST stable, but I have tried almost all of the hacks with no issues and im using the Sandisk Extreme 45mb/s cards
  • so the sandisk extreme 45mb/s is a good option right?
    that's the extreme pro, is it?
    I think the extreme is only 30mb/s.
    Im asking because I'm between these two, as my duracell "200x" ain't fast enough.

    thanks.
  • yeah the extreme pro if that is the one thats does 45 NOT 30... I have the 45 and its great
  • Hey I'm a lurker and first time poster to the forum...while you're on the subject of Sandisk extreme pro 45mb cards, I recently bought one hoping to enable me to use Driftwood's low GOP 720 50p patches (tried a few of his recent variations) but I keep getting record errors which kill the camera and I have to eject the battery in order for it to become responsive again - sometimes after a few seconds recording, other times can be up to 1 & 1/2 mins. I had been using Sandisk class 10 30mb cards previously which also had the same problems, so I had hoped upgrading to the 45mb card would have fixed it as I seem to remember reading that these cards were working fine for people.

    I bought the card from Amazon, not one of their third party sellers, so I am pretty sure it's a legit card. Has anyone managed to use this card with any low GOP patches for 50p without encountering card errors?

    Many Thanks

    Russell
  • @RJH Are you using a 3rd party battery? I'm really thinking your issue is not the fault of the card.
  • Try a low level format first. Im still awaiting the rest of the cards for evaluation - and a new card from Sandisk is being released next week.
  • I hope its even faster than the 45... and as for @RJH idk what to tell you here my friend... Im not having any issues and Ive run all but on of @driftwoods patches... as a matter of fact @driftwood I would like to know if your newest intra GOP1 for all but the GOP3 720 60p is the 24p mode the same as quant me baby... Im shooting a short film this weekend ND WOULD LOVE TO HAVE THE 24P OF QUANTMEBABY and better 72060p of the newest one...
  • Cool, thank u.
    I was about to order it from bh,
    But mow maybe i'll wait to see the newness from sandisk.
  • I'm making an attempt to get something going with 1080 60i and 720 60P. Here is a Stream Parser pict of a 66M GOP6 1080 60i patch. It starts out great, then quickly clamps down. I have no idea how to proceed. Any suggestions of which parameters to adjust would be welcome.
    1080 60i 66M GOP6 AQ2.jpg
    1282 x 667 - 277K
  • how do you implement the ini files? Just open and copy settings over in the GUI?
  • @No_SuRReNDeR I've tried it the original Panasonic battery and also with a third party battery, but it still throws up the same errors.

    @driftwood Is a low level format simply formatting the card in camera? If so I have done that about 4 times. I had no idea new cards were around the corner, that's just typical!

    @PerryWilson you haven't had any problems even with the 60p mode? It may be a silly question but does the hack enable PAL cameras to record with NTSC settings and vica versa? If so I would like to try it with 60p to see if I still encounter the same errors.



  • I dont have a PAL cam... but yeah 60p works fine for me... like I said ive done all but the latest GOP3 60p mode
  • Well I'm in NTSC land as well, so perhaps PAL has something to do with it, however I would say stay away from the 3rd party batteries I have a feeling they mess things up somehow.
  • Another incorrect statement by @eoshd:
    http://www.eoshd.com/content/4452/gh2-gets-avchd-intra-at-176mbit

    Driftwood 176M is not AVC Intra. It is AVCHD GOP 1. Get your facts straight.
  • @Ralph_B would really need to see your settings file, what stable patch did you base it on ? The 720p and the 1080i seem to share settings parameters so its more dificult than the 24H+L to get stable. Also, I'm only guessing based on my own attempts to up their bitrates at their original GOP, that there are very definite, much lower limits on frame limit, FBs and top/bottom settings. Breaking these can result in some very odd behaviour, such as recordings that refuse to stop without battery removal. Nope, I don't know what the limits are, but I'm pretty sure we won't be able to get really high bitrates similar to the 24H settings out of them. But, yeah, these are only guesses based on my own attempts today and a few weeks ago (when I gave up originally).

    I think the best approach is to try and get them stable at AQ0 first.
  • @sohus
    yeah well it's not the first time and it won't be the last:) Fact has little bearing with that site- good intentions though...
  • @sohus Meh, The only bad mistake there is claiming that its better for post work, which is very difficult to prove, (he did call it AVCHD-Intra not AVC-Intra as per his image graphic. Also transcoding to prores 4:4:4 from a 4:2:0 source is batshit crazy in my view, 4:2:2 is enough) Running all I-frames results in higher I-Frame compression, at GOP12 it is quite possible to get to the current max I-Frame size of 1,180,000 and the subsequent B and P frames can maintain the IQ at a lower bitrate. GOP1 has to compress more in order to fit into the bandwidth. As I showed in another test, the difference between the 176M GOP1 in post and the cbrandin 66M AQ2 is indistinguishable. In fact to my eyes, the 176M had slightly larger blocks visible when you cranked it up with curves.

    Also, IIRC Ralph_B did a test on the earlier 240M GOP1 and said it was very similar to the 66M AQ2, no big leap in quality compared to the HDMI out. Also green screen work is only going to benefit from 4:2:2 something we can't do. What the GOP1 does give is very different (arguably better) motion rendering, and less smeared noise (undoubtedly). If you're shooting a lot of fast motion then yeah, it probably will be a lot better in post. If not, no difference really to a longer GOP at a lower bitrate in post.

    Edit: And yeah, AVC-Intra with its 4:2:2 10bit space is massively different really. what we're getting is High 8 Intra (something completely new then) with more bitrate than High 10 Intra usually has. Also isn't AVC-Intra CBR at either 50 or 100 ?

    Ha, thinking about it, driftwood is right to say GOP1 creates a more consistent frame to frame bitrate, though the I-Frame size itself is smaller. Sooo.. if you had motion in shadows then maybe a long GOP would do a poorer job, but I'm not sure and it would need testing. Another thing I was thinking/wondering if you really tightened up the variation settings strictly limiting the available quantiser settings you may get close to something like CBR. Or it may just screw up and run out of bandwidth as its lost flexibility.

    Actually, no scratch that thought about GOP1 doing better holding detail in shadows if there is motion. It can't really unless its running at a constant bit rate if you think about it. I guess thats why AVC-Intra is CBR.

    I think a lot of people have hacked to the GOP1 and have never really looked at (or hacked too) the image quality you get out of any of the long GOP settings.
  • @Stray You are doing your best to kill GOP1! You make me laugh. :-) i frame rates are about to go up... I'm getting a bit fed up of you talking things through but actually never really offering anything new which hasnt been said before. STOP 'guessing'.
    Just crackon with your own 88M settings which are very good and be happy - you don't have to prove which is better - the diffferent GOPs are for different motion - we strive for quality in motion.Thats all you have to say.
    If one setting suits one, then for another a different setting is best.

    Chill out man,you can't save the world!
  • @Stray - "I think a lot of people have hacked to the GOP1 and have never really looked at (or hacked too) the image quality you get out of any of the long GOP settings."

    Can you name any? I think most of us using GOP1 are in fact heading there after trying all the longer gop alternatives.
  • @Ralph_B Ralph, hi. Its very difficult getting a balance of 1080/60i and 720p60 because they share many of the same settings in ptools - but they are very different in the way they handle the attributes. Hence the stock ones are pretty measly. Chris's (like you tested), and, indeed my own settings, tilt towards one or the other and to be able to give over the best settings we need two patches. One for 60i and one for 720p. Simple as that. They really are proving to be different beasts. Hence why I had to hand 720p a GOP of 3 rather than 1 on my collective settings.
    However, for 50i and 720p50 its a helluva lot easier. Believe you me, I have tested around 300 bins on 60i/720p60 alone - fuckin nightmare!
  • @driftwood keep up the good work... I use Driftwood ONLY settings, because they are the best, in the real world and in my tests
  • @PerryWilson hi, you'll have to wait for my next GOP1 settings - Im still testing and havent had a lot of time in the last 3 days.
  • I just tested the last patch of @Driftwood for a commercial. the quality is wonderful and the movements are extras! This is the best! In reality you just have a good SD Card Extreme Pro 45
  • @driftwood
    Do you have any thoughts on how to deal with that clamping down behavior?
  • I know it is GOP1. Calling it AVCHD Intra and an i-frame codec helps communicate that better than GOP1 which means nothing to most people. If you read the article properly I don't call it AVC Intra, I explain that it is AVCHD Intra and that is a phrase I coined myself. @sohus you know nothing about blogging!
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