Stutter problem with slow tracking shots, hack responsible?

M

mikrokev

Member
I've been using my hacked GH1 to do some slow dolly shots and I'm getting stuttery results. The stutters don't seem to be in the same places, but I get the same results on my Macbook, Playstation and PC. Any ideas what might be responsible?

See footage here :

http://www.youtube.com/watch?v=76hCcBDAEXE

After testing various settings the best results I got were with the 720p mjpeg, 30p, at 35mbits. The AVCHD footage was a lot more stuttery. The playback is evident pre-editing and I'm using iMovie to stitch it together.
 
Looks stuttery to me like a pulldown or interpolation error. Are you clicking 24p native? Are you removing pulldown correctly if not?
 
here's something interesting. Watch carefully and make note of the time points it stutters.
Then play it back a few times and see if those stutter points change ...
 
Blackout said:
Looks stuttery to me like a pulldown or interpolation error. Are you clicking 24p native? Are you removing pulldown correctly if not?
Click to expand...

Hi Blackout, thanks for your response. I shot in mjpeg mode, 30p not 24p, so I was presuming I wouldn't need to do a pulldown removal?

Are there any mbit rates or shutter speeds you would recommend for these type of shots?
 
mikrokev said:
I shot in mjpeg mode, 30p not 24p, so I was presuming I wouldn't need to do a pulldown removal?
Click to expand...

Correct, no pulldown removal if you shot 30p

But when you examine at the downloaded footage from youtube, the framerate is 25p , so there are decimated frames causing the jerkiness and small jumps

Double check to see what you uploaded is in fact 30p , or some mistake you made when editing . If the upload is ok, then it's youtube's fault
 
I never even watched it - just read the title of your thread and I knew.

Here's something that's going to flip you out. Try playing it with the VLC player and see if it stutters ...

edit:
http://www.videolan.org/vlc/
I'm pretty sure there is nothing wrong with your footage at all.
 
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Looks to me like 30p dropped into a 24 timeline (not conformed, etc.) Dropping frames in weird places, but looks 24p to me. What NLE are you using? Are your timeline settings 24p? If you're using Final Cut Studio try (on a backup copy of the clips as this edit is destructive and instant) conforming it to 23.976 in Cinema Tools. This will make it 20% slower (which might be a good look for your project) and should remove stuttering. That or just edit at 30p. As an above poster mentioned it's also possible your export settings got screwed up.
 
Thanks for all the great responses. PDR and Ben_B you are both right. I had exported incorrectly at a previous setting of 25fps not 30.

I've re-rendered it to 30fps and it's smoother. Though still slightly stuttery : http://vimeo.com/16455700

Also J Davis, I tried VLC and its the same as the everywhere else and the original camera footage- smoothish.. but still jumpy!
 
Here's the thing dude... just use 24p.... render to 24p.... 30p is for people trying to convert there old camcorder footage shot at 60i.. thats what it was created for. It's not a real shooting format in my eyes.
 
The 2nd one is better but it has some duplicated frames, and frames spaced incorrectly , this causes the "jumpiness" . It's not just because of flash playback because I checked on the vimeo encoded file (once it's downloaded) through a different player, and stepped through each frame with other software

I cannot download what you uploaded ( "this file is not available for download" ) to check to see if the problem was your export, to rule out if vimeo has done something incorrectly, or if it was something uploaded that already had the problems

Are you sure the original footage doesn't have the duplicate frames and spacing issue? The hack is known to cause issues such as dupe frames for some people

What settings and software are you using?
 
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Blackout said:
Here's the thing dude... just use 24p.... render to 24p.... 30p is for people trying to convert there old camcorder footage shot at 60i.. thats what it was created for. It's not a real shooting format in my eyes.
Click to expand...

Lol I have film professors that say we should shoot 30p because 24p is too jumpy and you can't get a proper pan and it's obsolete. I want to punch them in the throat. But I don't. It's a shame because all of them know their stuff really really well, it's just the course of actions they would take are different than the ones I would take.
 
Blackout said:
Here's the thing dude... just use 24p.... render to 24p.... 30p is for people trying to convert there old camcorder footage shot at 60i.. thats what it was created for. It's not a real shooting format in my eyes.
Click to expand...

okay thanks for the tip, will do next time!
 
PDR said:
The 2nd one is better but it has some duplicated frames, and frames spaced incorrectly , this causes the "jumpiness" . It's not just because of flash playback because I checked on the vimeo encoded file (once it's downloaded) through a different player, and stepped through each frame with other software

I cannot download what you uploaded ( "this file is not available for download" ) to check to see if the problem was your export, to rule out if vimeo has done something incorrectly, or if it was something uploaded that already had the problems

Are you sure the original footage doesn't have the duplicate frames and spacing issue? The hack is known to cause issues such as dupe frames for some people

What settings and software are you using?
Click to expand...


yeah i think the original footage has the dupe frames also. i was guessing it might be the hack pushing my camera / card too much.. i'm shooting 35mbps 30fps mjpeg. i opted for that setting after trying out many settings and it gave me the smoothest results.
 
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