FCP Frame Rate / Slow Motion Help at DVinfo.net
DV Info Net

Go Back   DV Info Net > Apple / Mac Post Production Solutions > Final Cut Suite

Final Cut Suite
Discussing the editing of all formats with FCS, FCP, FCE

Reply
 
Thread Tools Search this Thread
Old April 23rd, 2010, 02:47 PM   #1
Regular Crew
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 178
FCP Frame Rate / Slow Motion Help

Hi -

I've got a project where I'm trying to improve the look of some of my slow-motion footage.

First, some background:

A few months ago I did a promo for a client which involved a lot of footage from a soccer match. This promo is primarily to be published on the web (YouTube, Vimeo, etc.), and we decided on a frame rate of 30p.

The actual raw footage was shot in 60p (1280x720), with the intention that there would be a couple of slow-motion segments, so we could slow the footage down by half and have a really nice slo-mo.

Just one problem: At the time, I was editing in Final Cut Express. FCE is actually a very capable program, but you are limited to a very small set of sequence presets that Apple gives you. If you are particular about codecs and frame rates, you have to use FCP.

Here's the issue at hand:

When slowing down footage (by changing the playback speed of an individual clip), we only got half the frames that we expected. In other words, FCE appeared to first be converting the clip to 30p to conform with the timeline (tossing away every other frame), and THEN slowing it down again for our slo-mo reseulted in 15FPS.

Those problems aside, the client was happy and the project is done.

This week, I finally took the plunge and upgraded to Final Cut Studio / FCP7 (for a variety of reasons).

As a learning project, I decided to revisit this soccer promo. I made a copy of my original sequence and set the new sequence to be ProRes 422(HQ), 30p. Things looked a bit better in terms of resolution, but the slo-mo was having the same problem. (Strangely, unlike when creating a new sequence from scratch, you aren't allowed to change the frame rate of an existing one int he sequence settings dialog -- is that right?)

So for the next experiment, I created a blank sequence with a 60p frame rate, and then copied/pasted all my clips from the original sequence.

The clips didn't line up correctly on the new timeline, but that's something I can fix manually. But what's bugging me is that my slo-mo still has half as many frames in it as I would expect. What gives?

Do I need to pre-convert the clips I want to use as slow motion rather than changing the speed of the clip on the timeline?

Thanks in advance for any tips!
Bob Richardson is offline   Reply With Quote
Old April 23rd, 2010, 10:38 PM   #2
Major Player
 
Join Date: Feb 2009
Location: Vancouver Canada
Posts: 218
Yes, you should "pre-convert" the clips so they are already at 50% speed when you import them to Final Cut. If you have Cinema Tools, just open a 60p clip, hit Conform, and select 30p. Cinema Tools will instantaneously change the clip to 30p i.e. 50% slomo. Then edit in a 30p timeline.
__________________
Canon 5D Mark II || L-Series Lenses || Steadicam Pilot || Final Cut Studio
www.lovestorymedia.com
Erik Andersen is offline   Reply With Quote
Old April 23rd, 2010, 11:15 PM   #3
Regular Crew
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 178
Erik - Thank you for the reply. Yes, Cinema Tools is installed as part of the Final Cut Studio suite. I'll experiment tomorrow with pre-conversion and report back.
Bob Richardson is offline   Reply With Quote
Old April 26th, 2010, 05:22 PM   #4
Regular Crew
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 178
Hi -

Well unfortunately Cinema Tools did not like my original clip. When I attempted to Conform it to a new frame rate, it generated an error that the clip had "temporal compression". I'm guessing this is because the clip is in the XDCAM-EX format (it's a native clip from a JVC GY-HM700 camera).

However, I was able to place the clip in its own 60p sequence.

So, I did an experiment in getting 1/4 speed slow motion:

I used ProRes 422(HQ) to ensure that there was no visible degradation of the clip through the process. On the 60p timeline, I slowed the clip to 25%, giving an effective frame rate of 15fps. I then exported this to a ProRes QuickTime file.

I dragged the resulting QuickTime file into the viewer, set in/out points, and then drug it into my original 30p sequence. It performed as I had hoped, with a perceivable change every 2 frames, still maintaining an effective frame rate of 15fps. This looks much better than the original results I was getting previously.
Bob Richardson is offline   Reply With Quote
Old April 27th, 2010, 08:07 PM   #5
Major Player
 
Join Date: Feb 2009
Location: Vancouver Canada
Posts: 218
I've never had that happen, but you may want to try transcoding to ProRes first (using Compressor or MPEG Streamclip), then taking that file into Cinema Tools and conforming. If it works it will be a much quicker workflow.
__________________
Canon 5D Mark II || L-Series Lenses || Steadicam Pilot || Final Cut Studio
www.lovestorymedia.com
Erik Andersen is offline   Reply With Quote
Old April 27th, 2010, 11:58 PM   #6
Inner Circle
 
Join Date: Sep 2002
Location: Vancouver, British Columbia (formerly Winnipeg, Manitoba) Canada
Posts: 4,088
Yep, Cinema Tools wants INTRA frame compressed clips, not INTER frame (ie. MPEG derivatives and some others)
__________________
Shaun C. Roemich Road Dog Media - Vancouver, BC - Videographer - Webcaster
www.roaddogmedia.ca Blog: http://roaddogmedia.wordpress.com/
Shaun Roemich is offline   Reply With Quote
Old April 28th, 2010, 09:01 AM   #7
Go Go Godzilla
 
Join Date: Nov 2004
Location: Scottsdale, AZ USA
Posts: 2,788
Images: 15
Bob,

Unfortunately the speed tools built into FCS don't work that well despite Apple's initial push of "Optical Flow" technology as being the end-all for speed ramping.

I did a review of the Kronos tool, part of the Furnace Core pack from The Foundry:

furnace core - the Foundry

You'll get far better results - as good as Twixtor - without the high cost and much, much faster renders of the effect than anything FCS can do for you.
__________________
Robert Lane
Producer/Creator - Bike Pilots TV
Robert Lane is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK


DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Apple / Mac Post Production Solutions > Final Cut Suite

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



All times are GMT -6. The time now is 04:18 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network