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Convert 29.97p to 23.98p

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Alex Exline
Convert 29.97p to 23.98p
on Dec 3, 2013 at 1:57:55 am

Hi there I do apologize for any impending headaches. Long story short, I messed up on a few settings early on before this project took off the ground and now I need some help finalizing everything. We have a project with the following details...

Apple ProRes 422 30p
1920 x 1080
29.97p NDF
48kHz

We have been editing in this format since day 1, 90% of our cameras filmed at 29.97p (30p - pretty much all Sony xdcams). There are other mixed frame video from other misc. sources (its a documentary). No issues so far... we will picture lock and get audio stems to our composer/mixer and they will return those and everything will sync and it will be a blessed day.

After that glorious 1920x1080 29.97p master is exported from FCP, we will want a way to convert it to 23.98 for festivals and other deliverable packages that require it. So... now I'M LOST. It seems like 29.97i to 23.98p is a fairly easy thing, but for some reason 29.97p gets a thumbs down. I have talked to a video engineer buddy of mine and he said that a straight 2:3 pulldown won't work, but I could put it through a teranex (assuming this is a big expensive machine) and get something pretty good.

I wanted your thoughts on other ways to do this digitally with compressor/cinema tools. Again this won't be for misc. clips, this is for the final output video. Assume I know nothing, what are my options in compressor/cinema tools? I have tried a conform, which slows the video down. I did a frame rate change through compressor using the optical flow and to match clip time at 100% and it definitely changed it to 23.98 and the audio was identical. I just want to know if there is another way, or what the best practices are.

I have scoured the interwebs and found little on 29.97p > 23.98, so any help or advice you can give would be greatly appreciated!

Thanks all,

Alex


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Shane Ross
Re: Convert 29.97p to 23.98p
on Dec 3, 2013 at 4:24:47 am

30p to 24p conversion isn't the best. Even with a Terranex, it'll look a tad off. Engineer is right, 29.97 would convert a little better. No matter what, you will be losing 6 frames per second...6 frames dropped, so there will be odd skippiness. Compressor will do an OK job...as will Adobe After Effects...AE in a skilled hand will do pretty good.

I know a place in Los Angeles that will do the Terranex for $200/hour. $300 for a 90 min thing...done, out the door. File to file. Where are you located?

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Dec 31, 2014 at 4:10:51 am

Hi, Shane -
I need this service, too (convert 29.97p to 23.976p). Could you please suggest a place or software? Since this thread is from a year ago, I suppose new methods may now be available.

I have Compressor 4.1.3. When you say, "Compressor will do an OK job," what is "OK"? After running through Compressor, can I spot fix bad motion areas with some other software (dv2film, AE, Twixtor, other)?

Thanks for any more tips.

Nancy


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 7:15:34 am

Shane - Where is the place you know in LA that will do Teranex that cheap and fast?
Thanks,
Nancy


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Shane Ross
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 10:26:29 am

Tree Falls post...in the Cahuenga pass. Near Barham.

3131 Cahuenga Boulevard West, Los Angeles, CA 90068
(323) 851-0299

Ask for Mike. Say that I referred you to them. I've had a working relationship with them for about a decade now...

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 5:32:00 pm

Thanks, again, Shane!


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Keith Slavin
Re: Convert 29.97p to 23.98p
on Dec 3, 2013 at 6:24:24 am

Hi Alex,

Looks like you need high quality frame-rate conversion from 29.97p to 23.98p. isovideo provide fast turn-around, professional superior quality standards conversion/transcoding services (see http://isovideo.com/services.php) based on our 2013 IABM/NAB Game-Changer Award-winning Viarte server. We recently used Viarte for footage conversion (59.94i to 23.98p) for Ron Howard's “Made in America” documentary, which was world premiered at the Toronto International Film Festival on September 7, 2013. See details from http://isovideo.com/press_915.php. If you are interested in trying out our service, you could send email to keith@isovideo.com. We could run a quick test and see if it works for you.

Best,
Keith


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 12:35:21 am

Alex - Did you find a solution that worked for you? I need to do the same thing and would greatly appreciate any recommendations.
Thanks,
Nancy


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Shane Ross
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 12:38:04 am

Try using COMPRESSOR to do this...turn on the FRAME CONTROLS in the INSPECTOR and set everything to BEST. And be prepared to wait for a long time.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 12:48:11 am

Thanks, Shane.
I have Compressor 4.1.3.
Does Compressor simply drop frames?
(Looking for Frame Controls in the Inspector, and found these under the "Quality" section:
- Resize filter
- Retiming quality
Those have "Best" options to select.

There are also these:
Adaptive details - check or uncheck (default unchecked)
Anti-aliasing level - sliding bar 0-100 (default 0)
Details level - sliding bar 0-100 (default 0)

Should I alter any of the latter 3?

I had done a simpled-minded convert to 25 fps to see what that would do to scolling titles, and, wow, the studder is bad! I know I can convert the film without titles then add titles back at the proper frame rate in FCPX, but I just wanted to use that as a control on motion converts.

So, I'll try your recommendation to re-do it. Please just confirm if those are the FRAME CONTROLS you meant, and what I should do about the last 3 options.

Thank you!


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Shane Ross
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 1:06:16 am

[Nancy Kiang] "Does Compressor simply drop frames?"

Yes, but smartly. Although this really only looks smooth if you have 29.97 interlaced. 30p to 24p is simply a frame drop, and nothing really makes that look good. 30p to 24p and 24p to 30p is always messy.

[Nancy Kiang] "Adaptive details - check or uncheck (default unchecked)"

Check that. Leave the others alone. And RATE CONVERSION should be set to BEST.

Now, 30p to 25p...just as bad as 30p to 24p. 30i to 25p is slightly better, because you have fields to work with. But this is why a lot of networks want 24p masters delivered to them...because they convert to 25p better. 30fps to 25 is a standards conversion and not all that slick.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 1:18:16 am
Last Edited By Nancy Kiang on Jan 4, 2015 at 1:26:16 am

Thanks, again.

If there's still noticeable studder (stutter, judder, ...), then I may go with one of these post services that can do motion interpolation.

"30p to 24p is simply a frame drop, and nothing really makes that look good."
And 29.97p to 24p is also a frame drop, but just a tad less bad? (Just to clarify, some people round, some people don't...)

While we're at it:
- Is "ghosting" good or bad on a down-convert of frame rate? Is it like motion blur and should fool the eye, or is it wrong?

Okay, from here on, I shoot only in 24p...


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 4, 2015 at 4:48:37 am
Last Edited By Nancy Kiang on Jan 4, 2015 at 4:50:16 am

For others who may be reading this thread for advice, here are my results with Compressor 4.1.3:

Input: Scrolling titles white on black background, ProRes422 HQ, 1920x1080, 29.97p, 1 minute 18 seconds

Output 1: To Custom-> MXF 25 fps -> 1080p 422 Uncompressed (just for the helluvit, as I might make that my master file codec)
Settings in Inspector->Video: Defaults
Result: Render time 25 minutes? Awfully jerky scrolling titles

Output 2: To Custom-> MXF 25 fps -> 1080p 422 Uncompressed

Settings in Inspector->Video, Quality:
- Resize filter: Best
- Retiming quality: Best
- Adaptive details: Not checked
- Other options: Defaults (0 on sliding bar)

Results: Render time 40 minutes. Dramatically better than Output 1. No jerky motion, but slight twinkling in the scrolling text (this might be just due to my computer screen, since I see it a little in the original file, too).

Output 3: To Custom-> MXF 25 fps -> 1080i XDCAM HD 422 50 Mbps (the Uncompressed version wound up 8 Gb, and really no need for Uncompressed just to diagnose motion issues)

Settings in Inspector->Video, Quality:
- Resize filter: Best
- Retiming quality: Best
- Adaptive details: Checked
- Other options: Defaults (0 on sliding bar)

Results: Render time ~50 minutes. (Compressor doesn\'t show when it\'s done). Oy, the twinkly text of Output 2 became much worse, wobbly and uneven! Don\'t know if that\'s because of the codec or because Adaptive details was checked.


Output 4: To Custom-> MXF 25 fps -> 1080p 422 Uncompressed, to see if it\'s the codec or the Adaptive optics making things worse.

Settings in Inspector->Video, Quality:
- Resize filter: Best
- Retiming quality: Best
- Adaptive details: Checked
- Other options: Defaults (0 on sliding bar)

Results: Render time guess 40 minutes. The problem with Output 3 was recompressing to the XDCAM interlaced codec. Output 4 is just hint better than Output 2 and hard to tell, but the scrolling seems possibly smoother. It is pretty respectable compared to the original 29.97 fps clip, and I\'m guessing many people would not notice.

Conclusion: With these three options in Video Quality set to best, Compressor\'s convert from 29.97p to 25 fps is quite respectable. The catch is one should export to Uncompressed to avoid further degradation in other codecs, and it\'s odd one cannot select to output to the original ProRes codec as the input. So, at 40-45 minutes per 1:18 minutes for my film, and 8.17 GB Uncompressed, my 20-minute film will need 10-11.5 hours and 125 GB to convert. I guess I can tolerate that running overnight.

In Compressor 4.1.3, I don\'t see any option to output to Apple ProRes 422 HQ at non-29.97 frame rates: all the MXF output options do not include ProRes. I guess one\'s input file already has to be in the desired frame rate, and then video can be converted to other codecs. One can convert to both other frame rates and other codecs in the same export, but not to ProRes.

So, maybe one has to output to Uncompressed if one wants to bring one\'s file back into ProRes without losses?

I\'ll post results from the overnight convert here if it succeeds in finishing.


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Nancy Kiang
Re: Convert 29.97p to 23.98p
on Jan 7, 2015 at 6:03:09 pm

Results:
I did not run the whole film through Compressor, but I ran some scenes with combo of still, mild motion, and quick pans.

- Compressor on default settings, just dropping frames, results in jerky motion.

- With various combos of video quality settings set to Best and/or Adaptive Details checked, the output had significant ghosting on fast pans, regardles: it looks like Compressor merely overlays adjacent frames on top of each other (middle one full opacity, adjacent ones slightly transparent).

A Teranex produces the same results. Keith Slavin's Viarte automated system is far superior to the Teranex, with very smooth interpolation and not the shadow/ghost effect (at least on my footage).

- With video that does not have such quick pans, and in which motion is not so rapid (like a casual turning of the head), Compressor's results (with all settings at Best) are quite excellent!

So, for non-rapid motion, Compressor has no noticeable differences from the original (but need all Quality options set to Best and longer render times; without these, you'll get jerky motion). It's better to go with better software for shots with motion, like Twixtor or Keith Slavin's system.


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