Possible breakthrough on Native 24p!

[cbrandin]

Vitaliy,

I tested a bunch of different modes to try and determine what the 9000000 vs 18000000 constants mean. Nothing changes when I switch between FHD, SH, H, and L modes. This leads me to the conclusion that it might be related progressive vs. interlaced (wrapped) frames, using one value for 60p frames and the other for wrapped 60i frames. Any thoughts?

Chris

[Vitaliy Kiselev]

We need to move lower in AVCHD analizer to understand this empty or almost empty frames.
I can understand why frame can be almost empty after key frame (in static situation).
But why last frame in GOP have some problems is not easy to get.

[Vitaliy Kiselev]

Vitaliy,
I tested a bunch of different modes to try and determine what the 9000000 vs 18000000 constants mean. Nothing changes when I switch between FHD, SH, H, and L modes. This leads me to the conclusion that it might be related progressive vs. interlaced (wrapped) frames, using one value for 60p frames and the other for wrapped 60i frames. Any thoughts?

May be, it is hard to tell.
I am working of some things to allow speed up and improve testing.
It includes IDE modification, special IDC script, plus ability for PTool to use external patches (and use large arrays for them also).
Some file operations will be also opened in next database release.
Plus one safe location (routine that is executed upon Bracketing menu item selection).

[cbrandin]

In the 720p clips the 192 byte frames are devoid of image data. My tests are mostly, but not entirely static. When I look at the clips frame by frame there is absolutely no change - and there should be some changes. I test with a very slow pan on a static scene. I can't explain why they occur after an I frame instead of before, but I assure you they shouldn't be emply in either case. They happen with some regularity in both cases, so I don't think the Native 24p option is causing them - it's more like the wrapped 24p is hiding them.

Chris

[Vitaliy Kiselev]

In the 720p clips the 192 byte frames are devoid of image data. My tests are mostly, but not entirely static. When I look at the clips frame by frame there is absolutely no change - and there should be some changes. I test with a very slow pan on a static scene. I can't explain why they occur after an I frame instead of before, but I assure you they shouldn't be emply in either case. They happen with some regularity in both cases, so I don't think the Native 24p option is causing then - it's more like the wrapped 24p is hiding then.
Chris

In this case we must approach this professionally.
Look only on unmodified 720p footage. And strictly document testing procedures and provide short clips as well as analizing results.
After this we must publish open letter to Panasonic on one of the large techno sites. :-)

[cbrandin]

I'll see if I can make this happen with the factory default firmware, then.

Chris

[NPrincen]

I wonder if you shoot 24p in 60i wrapper and then remove the pulldown, whether you also see empty frames? As you say, the wrapper can be hiding empty frames, but they should reappear if unwrapped. Anybody tried this?

[cbrandin]

I don't know how you could do this. The best I can come up with is to process it with NeoScene and look frame by frame for non-changes. NeoScene will transcode, so looking at the output with an analyzer won't tell. But if you look at the transcoded clip with an editor you should be able to see if nothing changes from one frame to the next.

Chris

[Lpowell]

Did you get the failure with Navive 24p checked? Stream Parser shows a maximum bitrate of 110,297,900 bps in my tests. Does that match what you got?

Yes, my tests were with Native 24p at 86M Overall Bitrate. Stream Parser showed a max bitrate of 110M.

[NPrincen]

Yes, sorry, I forgot that none of the pulldown removal programs put things back in AVCHD, so the analyzer doesn't work. But, I think your suggestion would work. We would need to put it through NeoScene, then look for repeated frames. Unfortunately, I don't have NeoScene, otherwise I would look at this. Thanks for putting up with a suggestion from a noob.