DVX100a 24p/24pa to H.264 and MiniDV Workflow Help Needed...

C

Casey Pegram

New member
This is actually a (somewhat longwinded) series of questions, some having to do with Final Cut Pro, some having to do with Compressor, etc. Basically I could really use a rough sketch of what the proper sequence of events is to get a good quality H.264 encode from 24p footage shot with the DVX100a.

To begin. I shot in 24p (not advanced) mode and edited at 29.97fps. First question... can I bring this back to the original 24 frames? Do I even need to?

When I export to Compressor and encode in H.264 (LAN streaming), I assumed I wouldn't need to de-interlace since I shot progressive to begin with. But when I go frame by frame in the resulting Quicktime file, there is a fair amount of combing (signs of interlace). So I tried again with de-interlace turned on in Compressor. This made it even worse! Looks like half the original resolution, pixelated, nasty, and STILL some combing issues.

Now, I know if I play the original file on a television, it would probably look fine. But on a computer, it's not so great. So how does one export 24p footage to the web and to dvd, and is there a step (like pulldown) to get back to the original 24 frames at some point? Because I think that's the problem.

I would typically just shoot 24pa, but this project's final destination is DV tape (it's a production class assignment and that's the desired format of the instructor). So I assume if I shoot in 24pa and then edit at 24fps, I'm going to have problems going back to 29.97 interlaced DV.

As you can tell I'm kind in search of something to get me started down the right path here. How to handle each form of 24p, how to get a good encode for the web, how to get it back onto DV tape, etc.

If you need more details, please let me know, I might've left something important out. I can also upload some screenshots of the interlaced combing I'm seeing if that helps at all.

Thanks in advance!
 
You can shoot 24pa, edit 23.98 and then output to 29.97 interlaced DV depending on your editing software. FCP does this on playback so that's not a problem.
If your target is web or computer then convert to 23.98 for 24.pa or 24p.
You're seeing interlacing since 24p (and 24pa) without pullodwn remove will have interlacing on some frames. That's why you want to edit at the true fps if you need clean progressive images.
It's very tough to do after editing since you may have cut on a field and having the system figure out cadence on short, cut clips is difficult.
 
Thanks for your help, I think I'm getting the hang of it now. Luckily this was really only one shot I've done so far for this project (a time-lapse test, not even the real thing yet), so editing again is not much of an issue.

Just now I used Cinema Tools to remove the pulldown from my 24p footage, but it seems like it's actually sped up the motion of the footage. I used the reverse telecine to bring it down to 23.98fps. To me though it looks more like 15p - exaggerated motion, things happening faster, like an old silent film or something. Any ideas? Maybe Cinema Tools is playing it back at 29.97fps still and it's just a matter of loading it into the 23.98 timeline, I'll give that a shot...

Edit: Actually, yeah, looking at the duration in Final Cut, the original clip was 23:16:22 and with pulldown removed it's 17:35:12. That can't be right, right? I must've missed a step.
 
I'm confused... "Time Lapse" as in using the Intervalometer function of the camera?
I don't recall that being an option in any of the 24 frame modes.
 
thisiswells said:
I'm confused... "Time Lapse" as in using the Intervalometer function of the camera?
I don't recall that being an option in any of the 24 frame modes.
Click to expand...

You're right, I should clarify this. Because I did want to have a progressive time-lapse, and I also wanted to transition into it from a normal shot following one of the characters, I decided I would just shoot real-time and speed it up in post. So the only real time-lapse that's happening is in Final Cut - sorry about that.

I should note that it does work really well, especially for 24pa. When you speed it up, Final Cut basically just takes out frames. You can brush through and everything is still the original frame, provided you have frame blending off. Otherwise there is a little bit of a transition added which you might or might not like.

In the future I'll probably experiment with using a laptop to capture footage from firewire and do progressive interval recording that way, but in a pinch this method worked fine (it also helps, obviously, if your lapse subject can be captured in under an hour - in my case, the moon rising above a house).
 
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