Yes I have Towi. The difference between replacing T4 with T2 as opposed to T1 is negligble, but my tests weren't exactly great, I just wanted to see if it fixed the cadence problem. I did notice some small pulsing sections with the T2 in streamparser, but it was probably down to what I was actually shooting (and I couldnt see anything noticeable hapening to the footage, but havent analysed it properly). Anyway the still scene I shot for 2 minutes did settle down into a consistent pattern, its just the switch from the first 20 odd seconds to slightly different frame sizes that is still weird. I'd like to spend more time on this but things are pretty hectic here, so I'm doing these tests while doing other things.

Vitaliy, any thoughts on the frame size changes I see after 20 seconds where B frames grow and I and P frames shrink ? I think what I'm asking really is what is the trade off for this solution ?

Edit : If you check the overall bit rates things seem to stay consistent accross the tables used, its just where the bit rate is allocated that seems to alter with each table. But I'm only guessing.

>what do these settings do at all?

They alter quantizer tables used.
T4 is fallback tables used if encoder thinks that remaining bitrate is very low.

@cbrandin
GH2 filtering image at 24 qp min before being decoded.
it looks like a significant loss of quality.
Perhaps this is a reason we do not see a drastic difference between 44 and 88 mbit .
if we could reduce the value or to exclude filtering it would allow the codec to work with the original image values.

Ok will do, thanks.

Vitaliy,
Are there any drawbacks to doing that? Is there a compromise of details or motion? Will it lower any kind of quality?

Sorry, forgot to say, I've mostly been shooting with a GOP of 12. Also, there actually doesn't seem to be much wrong with the footage itself when I play it back, but I guess I'd notice it in post if I had time to play with it.

PTool v3.62d cannot produce stable settings for me, the uneven cadence always appear at some point in the clip. I never went over 44Mb, played with buffers, AQ, GOP, or used defaults, or variations of such, but always the cadence issue. I reverted to stock firmware for now.

p.s.: I did all my test with the voigtlander 25mm and on manual mode only.

I think Panasonic gets around some of the filtering CPU overhead by using pre-calculated tables. Those tables don't change below a QP of about 24. My guess is that they didn't bother with lower settings because they assume the QP will never go below 20 (the factory low limit). I think I know where they are, but the parameter tables have other stuff mixed in. I'll have to decipher what they are doing.

Chris

Спасибо за ваш хак Виталий

that means we can use auto qauantizer and manual QP settings together?


vladimir

@cbrandin
so if i use 88m AQ4 minimal QP can go to 8 , factory QP 20-12.
what will hapen if i add minimal value 1 in AVCHD ST.
can qp go that low?

Please delete.

for 50i I wouldn't raise the bitrate over 32Mbits (default doubled)... lots of artefacts can happen in motion otherwise. I never understood the values suggested in PTool.
The new AQ patches however DO improve IQ... 50i looks remarkably better than the stock GH2.