Official Low GOP topic

danyyyel

"on longer gop the jello is no more and amplified" I can't update my above post, it have been read "on longer gop the jello is more and amplified"

bdegazio

@jamesgh2

"I would truly love a way to extend 24H to 30frame H. That would make this camera unbeatable."

Shoot in 24H, 80% mode. There's no sound, and you have to conform the file to 30p on playback but it works fine and produces true 1080p30.

jfro

@cbrandin @kea

I was getting a circle going round and round. I went back to find the 2 files as I haven't reformatted the card. I'm on the same computer and now they all play. Best guess is it was operator error and I just was impatient. Most of my tests today have been rather short and it usually load the files in under 10 seconds. I probably got impatient around 45 seconds. Even though I don't recall which files on the card gave me trouble, one of the files I thought it might be was around 3 minutes as opposed to the 60 second tests I was doing.

Again, sorry for the non issue.

I'm hoping for some more time tonight for a little more testing. Hoping we can get some more magic out of this little camera.

svart

@Kae
Set your 720p60 settings with B frames and immediate got card speed error which locked camera up. :)

APXmusic

@Shield, yup there are blips! Just the first few frames

cbrandin

@jfro

There is a quick test option under files that just opens a small part of the file. It's very fast, even with big files. You'll only see the beginning part, though.

Chris

Donnie88

@danyyyel - That's exactly what made me want to find out. Not sure if anyone even knows!

jamesgh2

@bdegazio

Thank you, I do use that from time to time but its horrid when you need to sound sync. Seems Vitaliy is working on getting 80% to have sound recorded also. That would fix it!

BTW I got kae's latest settings to give me 64megabits average 74 peak on water with heavy splashing. No crash and gorgeous!

jfro

@cbrandin

Quick test, thanks. My new go to menu item 90% of the time.

@butt & @kea Playing with your to latest settings and am getting some write errors, even after formating with camera. Fairly frequently on the 24p setting. Only other test with 1080i and that seem ok for about 6 or so shots. I'll try other cards later, but is is a transend class 10, 16gb. Never had issues with any cards before so I don't think it's a card issue. Will try 60p next.

kae

@Angry_C

Wow. That seems like a lot of errors. Did you reformat the card before all your tests? I do with mine. Strange I am shooting the same death chart and get no errors - so if 10 out of 10 times you get errors on the death chart with 720P 60 and I can shoot it 4 minutes straight with no error, it's either your card, you need to reformat or something is weird. I'll have to let others tweak the 720P/1080i settings then as I never use them. Perhaps just set the GOP for 1080i/60 and 720P 50/60 back to the defaults which are GOP 30 for 720P/60, GOP 24 for 720P/50 and GOP 15 for 1080i/60 and see if you get errors (you can set the 1080i/50 GOP without changing 24P). All those modes are obviously video modes that can't be filmic anyway so perhaps shorter GOP here is overkill. But glad to see 1080 24P works great, this is the focus of my time. Also, I have never tested anything with the telex mode? Perhaps this is part of the problem???

kae

@svart

Did you get the lockup with p frames?

kae

@jamesgh2
'I would truly love a way to extend 24H to 30frame H. That would make this camera unbeatable.'

I agree. I don't know why someone can't figure out how to make the 720P and 1080i modes write up to 64mbits like 1080 24p is doing. But I think the reason the 1080 24p looks so stellar in comparison is the data rate is so much lower in 720p.

kae

@jfro
'Playing with your to latest settings and am getting some write errors, even after formating with camera. Fairly frequently on the 24p setting.'

Odd. I'd say it's the card. Remember 64mb/s is the highest the Gh2 has written so far for AVCHD. Have you tried Lpowell's 100mbut mpeg settings yet? Do those clips write without error?

stoney

Finally home. I tried @kae's 1024p24 65Mbps GOP3 on my bush of death. It's my overgrown Japanese Maple tree. GH17 failed in a few secs. GH2vk... wow. Super sharp. No crash. Happy me.

StreamParser is pretty much like other people's. Low bitrate on first 10 frames. Then close to 65Mbps for the rest.

1080i is tied to 720p settings. Maybe 1080i gotta be sacrified? GOP6 for 720p60 would be great but that might require higher than 42,000,000 bitrate as 10 I-frames and 50 P(?) frames might exhaust the bitrate. If 42M is max bitrate, tweak 720p60 top and bottom settings to target for the bitrate?

Already in night here. Can't test it out. Going to another trip tomorrow. Hopefully someone can test it.

jfro

@kae I went back to your 24p only settings for 2-3 days ago and recorded 6 clips without any write errors. Will keep checking a try other cards tomorrow. Tired and probably done for the night. Is any one using Transcend 16GB cards. Never had issues with these before.

svart

@kae
the settings should apply I, B and P frames like 24H does, however I get immediate failures resulting in 0byte files so I can't look at them in stream parser.

kae

@jfro
"I went back to your 24p only settings for 2-3 days ago and recorded 6 clips without any write errors"

Then stay with those settings if they work. For 1080 24P I think the only difference was they capped at 60mb/s rather than 65mb/s. Not enough to make a hug difference quality-wise, especially if they are giving you problems.

kae

@svart

Were you ever able to get b frames to work in 720P at any GOP length?

kae

@stonebat

"1080i is tied to 720p settings. Maybe 1080i gotta be sacrified? GOP6 for 720p60 would be great but that might require higher than 42,000,000 bitrate as 10 I-frames and 50 P(?) frames might exhaust the bitrate. If 42M is max bitrate, tweak 720p60 top and bottom settings to target for the bitrate?"

Only 1080i/50 shares the same GOP setting as 1080 24p. 1080i/60, 720P 60 and 720P 50 are free to change at will. So set them back to default for everything and those modes will work fine. So far only rock-solid 1080i/50 mode has to be sacrificed for the extreme 65mb/s 1080 24P mode to work.

And I have a feeling the other non 24p modes can provide much larger bitrate (probably by tweaking high/low settings) but others are working on those modes.

svart

@kae

I have not tried other GOP yet, I didn't have time today.

I read in another thread that it works but don't remember all the details. Will have to go back and re-read what the settings were.

APXmusic

@kae Hey man! With all these posts, could you give us a rundown on what is currently the best settings that you have made?

kae

@kae

For 1080 24P 3 GOP definitely the latest one posted above with all the charts, it seems pretty solid. But I can't vouch for the stability of the settings for other modes. I have no problem with them but others do.

proaudio4

Is there a way to bring up the minimum bitrate? This would bring up the average bitrate and help low light levels approaching black. Sorry, If this information has previously been available.

kae

@proaudio4

Good question for Vitaliy. Perhaps with the high/low bottom settings?

last_SHIFT

@proaudio4,

I seem to recall bringing up the min bitrate will come after VK and Chris progress with the quantization process.

http://www.personal-view.com./talks/discussion/366/pro-avchd-quantization-process#Item_3

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