Compressor / HV20 / ProRes Question

[Paul Escandon]

So are you applying the quicktime flip script that I provided before starting the compressor pulldown removal workflow for your HV20 clips and when compressor is finished the ProRes422 files are right-side-up? That’s great if so – I didn’t even think about doing it first, then compressor last.

If it takes longer I guess that is the only draw back… how much longer are we talking?

Peace!

* * *
Paul Escandon
Producer | Director | Editor
Apple Certified Trainer – Final Cut Pro
Oremus Productions
http://www.oremusproductions.com
– –
Adjunct Professor of Media
John Paul the Great Catholic University

[Casey Pegram]

Paul wrote:

“So are you applying the quicktime flip script that I provided before starting the compressor pulldown removal workflow for your HV20 clips and when compressor is finished the ProRes422 files are right-side-up?”

Yep, that is it precisely! FCP doesn’t honor the flip, but Compressor does.

Unfortunately it is taking a lot longer – I tried it just now on a clip lasting 3 minutes and 6 seconds and it came in just under 20 minutes, so a little over 6x realtime. When I tried it again using the actual file (not reference, not flipped) it took just under 6, so 2x realtime. And then manually flipping the actual file and submitting that rather than the reference, same result (6x realtime).

So, it’s about a 300% increase in time if you do the flip this way. But I think for me at least it’s probably still a worthwhile way of handling it, for the space you save and also the performance enhancements in FCP from having one less filter on your 1080p footage.

Six hours for one hour of footage though, hmm.

[Casey Pegram]

Actually, now that I think of it, I bet the increase in time might have something to do with the fact that it’s having to use the native HDV footage to flip and then transcode that into ProRes. HDV rendering times, in my experience, are pretty painful. I wonder if it wouldn’t be faster to just do the regular HDV -> ProRes thing, THEN flip the ProRes file and re-render that out (since generational losses in quality aren’t much of an issue with ProRes). As long as it could be scripted to where it didn’t take a lot of manual intervention, that might be worth a shot…

[Casey Pegram]

One last follow-up in case anyone else was reading this and considering implementing the workflow: it’s probably not a good idea.

Reviewing some of the footage I shot tonight, which I captured in FCP as regular HDV and then ran through the pre-flip –> pulldown removal –> ProRes workflow, I starting noticing lots of weird interlace artifacts in my 23.98 clips. I’m not sure what’s causing it, but my guess is that doing the flip before sending it to Compressor is messing up the reverse telecine somehow. Looking at the same clip done with the new method and the old method, the difference in quality was immediate. If anyone is curious and wants to see frame comparisons, let me know and I can post a few.

I still like the idea of baking in the flop, however… I’m running into a new problem now with Compressor because it seems unwilling or unable to “transcode” ProRes back into ProRes (the only difference being I’ve rotated the footage 180 degrees). If anyone has any ideas on how to accomplish that, do please chime in.

[Jeremy Garchow]

Casey. Acutally that makes perfect sense as by flipping the image you are reversing the field order so perhaps that’s why it looks the way it does. So can you remove pulldown then flip?

[Casey Pegram] “I’m running into a new problem now with Compressor because it seems unwilling or unable to “transcode” ProRes back into ProRes”

What do you mean by this?

Also for all your future productions:

https://www.redrockmicro.com/microx.html

[Casey Pegram]

Jeremy,

I can remove pulldown and then flip, but the problem is I apparently can’t then save the flipped version back out to another ProRes file. What I wanted to do is start with the usual HDV -> Reverse Telecine/ProRes workflow, then flip it in Quicktime and save that back out as another ProRes file with Compressor. Since ProRes apparently doesn’t take much of a hit when you go through multiple generations of compression, I figured it wouldn’t hurt the image quality much. The reason for resaving it rather than just flipping in Quicktime and loading into FCP is that FCP doesn’t honor this flip until after you’ve rendered. Anyway, if I flip it in Quicktime, then throw that file into Compressor and tell it to compress it as ProRes to a new file, I get a “Codec not installed” error. Since I’m going from ProRes to ProRes I can only guess that that’s the problem – I can still encode ProRes from other things without issue. Doubtless I could probably do this without a problem in Final Cut or what have you, but then it starts eating up more time than just doing the NLE flop and render to begin with.

As for the Redrock flip unit – maybe! I would be inclined to get the SGpro one as that’s the adapter I’m using (manufactured I believe by the Letus guys) but I’ll certainly consider the Redrock one if it truly has the least amount of light loss. That’s the main reason (well, that and spending more money) that I’ve avoided the in-camera flip as it is.

[Jeremy Garchow]

Sorry, I thought you had a Redrock. We shot with the P+S Technik and an HVX200 late last year for the first time and we were all blown away. No flip on that one either. But I digress.

[Casey Pegram] “Anyway, if I flip it in Quicktime, then throw that file into Compressor and tell it to compress it as ProRes to a new file, I get a “Codec not installed” error.”

That doesn’t seem right. Let me do some messing around.

[Jeremy Garchow]

I don’t know, Casey. You should be able to go ProRes to ProRes. Something else is wrong there.

Jeremy