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Black frame caps when converting frame rate in timeline
Dear all,
I’m finishing off a project right now and have some questions about our final conform / online.
The project was shot partly DVCProHD 25, and partly DVCPro 23.98. Because we’d want to master in 23.98 (HDCam SR), and eventually film, we opt to edit in 23.98 timeline in FCP.
We had not transcoded any of the 25 fps footage, and just dropped them straight into our 23.98 time line mixing with the other material. To complicate matters, the audio were all recorded separate, and when editing, we were using synced subclips.
Right now, we are ready to conform, and had secured a slot to do hardware transcode of the 25 material to 23.98. We are asked to provide the material as 25fps.
I am wondering if there’s a proper way of re-creating my edit timeline into 25fps?
I tried creating a 25fps sequence (with DVCProHD25 preset), and copy / pasting all the clips from the 23.98 edit sequence into it. However, I find that there are on occasions, black frames b/w edits and that sometimes the audio would be -1 frame shifted.
I am wondering if this is normal, and if all I need to do is to close those gaps, and re-adjust the one frame offset of the audio.
A follow up question is that we are in a rush to provide OMF to our post-sound designer. Is there a way to provide OMF to them now (perhaps off the 23.98 edit sequence), or I should hold off until all conversion is done? In theory, since we edited on the 23.98 sequence, I think that the eventual “processed audio” along with the video would fit into the same duration as what I have on the 23.98 timeline. But, the black frames worries me in that there seem to be an offset.
Perhaps I need to wait until all conversion is done (video and audio, if any) before heading to post-sound?
Thank you for your time.
Michael
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[https://www.dvshortfilms.com]
[https://www.mksiu.com] -
3 Replies
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Hi Michael,
You can put almost everything in an FC sequence, but stuff with a time base different than the one of the sequence. Do not work.
You need to conver’t the 23’97 stuff to 25. The best option is not a “Hardware Standard Conversion” (probably very expensive), but conform the footage in CinemaTools. No rendering, no quality lost.
I’m afraid that you will need to rebuild your sequence in 25fps.
rafael -
What Raf said. When working with mixed frame rates, ALWAYS ALWAYS convert everything to the same frame rate before editing. Having Cinema Tools do a simple CONFORM to 23.98 and getting a small 4% speed change would have been all you needed to do. Unnoticeable speed change. After the fact, you have to convert and manually replace all of your shots. DUPLICATE THE MEDIA FIRST…Cinema Tools is destructive in the way it manages clips when Conforming.
And yes, any time you copy clips of one frame rate into a sequence of another, gaps appear. This is because of the time base mismatch. Only way to fix is to manually close the gaps. That being said this is NOT the way to get 25fps to 23.98. Conform in CT is my suggestion.
Shane
GETTING ORGANIZED WITH FINAL CUT PRO DVD…don’t miss it.
Read my blog, Little Frog in High Def -
Thank you both for your replies. I have a few follow up questions:
1. If I do a conform (re-time) of the footage, from 23.98 to 25; or 25 to 23.98, what is the exact speed change I need to implement to the audio? I noticed that when doing a conform on Cinema Tool that the sound is not treated, and that the sound will need to be treated separate. I am afraid that I will be met with audio offsets / drifts down the line.
2. When doing a transcoding (where the media duration remains the same, not conform where the duration lengthens / shortens), I have been told that it is better to go from a lower frame rate to a higher one. This was because pulling out frames is destructive to the motion since information is being left out; but adding frames will be much less noticeable, if at all. How does this apply to conform. Should I go 23.98 – 25; or 25 – 23.98? I understand the speed change is minute, but through my test it is still noticeable. Is there a general standard to whether speeding up / slowing down is preferred?
3. In regards to the gaps – because I have multiple layers of audio, and sometimes the audio have dissolves b/w files, I noticed that sometimes sometimes there are gaps in the video, but not in the audio. Should I follow the duration of the video and adjust the audio accordingly?
Thank you again!
Michael
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[https://www.michaelmksiu]
[https://www.dvshortfilms.com]—
[ http://www.dvshortfilms.com ]
[ http://www.mksiu.com ]
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