For what it's worth, we're getting great results with gop12. Shadow grain equal (or close to equal) to what we were getting with gop3 with 3.61.

I did some more testing and 42 mb/sec 720p is not stable with the new settings for very bright scenes with ETC. I tried everyone of the new Quant settings for 720p and they would all fail after about 20 seconds with ETC and a very fast shutter speed.

I have revised my settings to use 38 mb/sec and Quant = 3 for 720p. That fixed the ETC issue even for my slow Class 6 eye-fi card. Quality looks the exact same so I really don't believe that I am missing anything.

I am still using 42 mb/sec and Quant 4 for 1080p and that has no issues even with the class 6 card. I plan on testing the 1080p mode to see at what level it becomes unstable.

@towi - We're testing with your settings right now. Getting good, long takes (10 min) at high iso with the low setting, but no joy (long takes at high iso) with the high... Will keep messing around and give better notes in the AM. - additionally, are you doing much high iso testing?

does anyone have footage of i frames above 8.4 with no macroblocking? i can't seem to find the right settings..

@towi, I tried your settings (with top/bottom settings), and the cadence problem is still there. I've had similar findings relating to shooting the death chart, the cadence issue doesn't arise sometimes. Also the motion itself looks very, very odd to me.

@cosimo_bullo

Here are the settings I am currently using. The 720p is pretty much maxed out for 100% stability. The 1080p one could go higher but I am starting to doubt whether that is necessary or not.

@cosimo_bullo
My procedure is to make a setting that shows an even cadence in streamparser to start with.
I then record the infamous torture chart about 30 seconds in 24H, 24L and FSH and look at the streams.
When the streams look okay, I record longer clips (2 or 3 minutes).
When the settings seem to be okay I continue testing under real world conditions (motion, gradients etc.).
Typically I do use low and mid ISO. I also check high ISO but actually not with long clips (2-3min max for testing purposes mostly).

This morning I've also tried to simply double everything (so 44Mbps at 24H and top/bottom BR settings doubled).
With the 88/48/32Mbps settings posted above as well as with the new 44/32/32Mbps settings from today my camera records without issues up to 4.29GB file size.
The files don't span ... either way the settings I use. So I suspect this is not an issue of high bitrate but a general issue with PTool 6.2 (with 6.1 at 52Mbit/GOP6 the files span fine on class 6 and class 10 SanDisk).

I do like the improved IQ of the new autoquantizer, especially as 50i is now more than just usable... this is why I will stay with the PTool 6.2 firmware for the time being. The settings posted above didn't crash my camera by now... so I will continue to test them (limited time to test right now, unfortunately).


@Stray
odd. Attached 4 screenshots.
First two show a relatively still scene (backyard with trees)
1.) 8 minutes shot with the 24H/88Mbps setting posted above (average bitrate actually utilized: 68Mbps)
2.) 13 minutes shot with more moderate 24H/44Mbps settings from today (average bitrate actually utilized: 42Mbps)
Both streams show an even cadence all over the clip length.

the next two are from a scene with motion (passing traffic).
3.) 16 minutes record with the 24L/32Mbps setting from today (average bitrate actually utilized: 30.7Mbps).
Cadence looks good up to ~ 6150 frames. Then the cadence looks weird, however the actual footage looks good (shows no artefacts or strange behavier that is).
4.) 6'30'' record with 24H/88Mbps - even cadence all over the clip.

Interesstingly all clips I've shot by now with the "SetE" 88Mbps@24H posted above show an even cadence .. either way whether or not the scene required the codec to go at really high bitrates.
Only with lower bitrates and the 24L setting I get the uneven cadence occasionally (as in screenshot #3).
I have no idea why … this is just how it is.

Now, it is very well possible that something does not work with these settings, of course... but by now I have not discovered issues with my camera and my cards (except, of course, the files don't span).
Clips also playback fine in camera (at 24H sometimes I have to switch off/on the camera to play the files, but this is a non-issue for me personally).

Did you load my settings or did you create your own? In the case of the latter... maybe you forgot to check or uncheck a setting?
Also, after loading a new firmware it's mandatory to reformat the card in camera before you start to record something ... but I am sure you already know that.

As to "odd looking motion" ... how do you view the files? In my book it's pretty useless to judge 24p files on a computer monitor. Too, when you playback MTS files there might be any kind of artefacts and "shutter" issues due to the processor intensive "on the fly" decoding of the application used for playback.
To judge IQ and especially motion this is what I do: I import my files into Avid and eye up the movies on a monitor that displays native 24p (at 24Hz).
At least you should transcode to QT with a high bitrate (ProRes, DNxHD or so) as those files do not stress the processor that much.
To me the footage looks good (admittedly this statement is only based on limited tests … but I will keep on testing with my "SetE" 88/48/32Mbps setting).

My camera is set to PAL.
Cards used are SanDisk cl.6 and cl.10.

the version posted here on July, 26th?
-> http://personal-view.com/talks/discussion/comment/7635#Comment_7635

@Towi, you say the footage looks good even with the uneven cadence, I've felt much the same about it too. Have you exported stills before and after the cadence goes whacky to check it ? I'm using Sandisk Extreme Pro for everything.

@cbrandin - We're seeing a big enough difference between 44 and 88 in 3.62 to justify the higher bitrate (I realize this is somewhat subjective, and that's fine). Also, I'm hearing that the lower settings are not helping towi's cadence results, and that 88 is actually giving a more solid cadence. Is that correct?

Only with a LOT of motion (like a cattail plant blowing hard in a breeze with a 500th shutter) for the most part. The real improvement for me is the quality of the grain/noise in shadows and less banding in out-of-focus color areas. We just did a couple of tests to exemplify this, though I think some will say we're crazy, as the results are subtle. But to me this is about subtle refinement. The GH1 sucked before the hack. The GH2 was great, and now it's getting better and better. One little example: we just reshot on the GH2 a shot in title sequence that was otherwise all RED (pre MX, but very clean). It was projected last week to a fairly large audience, and NO ONE noticed the replaced shot, not even people who were there at the original shoot! That was with 3.61 at 110mbps. 3.62 at 88 looks even better. That, to me, is what this is all about.

@Stray

"24H lower to 66MB and did a 3x multiple on its top/bottom instead"
I thought exactly about the same setting. Will check it …
66Mbps would be fine for me… I've just pushed to 88Mbps as it seems to produce even cadences and quite stable high bitrates.
Also with the high setting I-Frames don't go really low in motion … only the P- and B-Frames get larger.
With lower Mbps settings I-Frames go sgnificantly lower in motion.
Okay, this is how AVC codecs are supposed to work according to "cbrandin". And it makes sense.
But it doesn't necessarily mean that it's good thing … AVC codecs are certainly not the holy grail of video codecs :-)


"I don't know if you saw it but Vitaliy said in another thread to leave those top/bottom settings alone as they're fine as they are"
Now … I really have no glue about all this. I am just a user, absolutely no engineer or so.
So Vitaly is certainly perfectly right.
On the other hand "cbrandin" told us by default the GH2's I-Frames are limited to 8MB.
To improve IQ you have to "enable" larger I-Frames by altering the Frame buffer sizes and Encoder frame limits.
Multiplying FBS and EFL by 2 or 4 works - the I-Frames go well above 9MB.
But this procedure seems to be quite prone to crash the codec or at least there are issues with in camera playback and transcoding.
Raising the Top/Bottom Bitrate settings also enables larger I-Frames. They are not quite as large but I feel the camera is much more stable with these settings.
Why did I try to raise the Top/Bottom BR setts? Well, simply because a lot of people did just that with PTool 6.1 … and as a consequence we could produce stable higher bitrates. That's all actually - I just recalled the settings from PTool 6.1 …


"you say the footage looks good even with the uneven cadence, I've felt much the same about it too. Have you exported stills before and after the cadence goes whacky to check it ?"
Stills? No. I play a loop from ~ 5 seconds before the cadence changes to ~ 10 seconds after and check different areas of the scene in motion. I can't see that the noise pattern is changing nor can I see pusling or crippled image details or so…
Apparently the uneven cadences do not destroy IQ. On the other hand it's certainly not what the stream should look like … so in fact it makes me a bit nervous.