Converting 60p to 25p and keeping same playback speed

Hi there,

First time posting here, hope you can help.

I'm working on a project in FCPX (10.0.9) and I have some GoPro footage shot at 60p i need to use in the project, the rest of my footage (98% of the footage) is shot at 25p (and that's what the project is set to). The 60p footage is kind of jumpy and not as smooth as the original, this is obviously because it's being played back at 25p.

My questions is... is there a way to convert the footage down to 25p and maintain the quality and speed of playback of the original footage?

If this is not possible, will changing the frame rate of the entire project to 60p effect the footage shot at 25p in any way?

What are my options? I've looked around online but couldn't find a definitive answer.

Apologies for the gaps in my knowledge!

Thanks in advance for your replies!

Thanks.

Is the GoPro footage rendered in the project? Is it 60fps or 59.94fps?

Thanks so the quick reply!

The GoPro footage is rendered in the project, I've even exported a master file of the whole project to check, and it's still not smooth. By jumpy, i mean, it's not jumpy in the sense like when it hasn't rendered, it's just not smooth, like the original file.

The GoPro footage is 59.94fps.

Thanks!

JM1 wrote: … it's just not smooth, like the original file. …

people tend to forget the effect of 'angle speed', rsp. how to use motion-blur...

I like this website
frames-per-second.appspot.com
which illustrates this point 'interactively' ... plain&simple.

or, in my amateurish words:
if an objects moves lateral and close to cam fast, more frames per second add smoothness; if a higher fps isn't optional, you have to add motion-blur = lower shutter speed...

but when you change the playback-rate afterwards, you're in trouble
afaik, there're costly plug-ins avail to apply motion-blur in post (Twixtor? Not sure ....)

I've found it safer to shoot in a multiple of what my delivery (Timeline) will be. I deliver mostly 30p, so for slo-mo I shoot 120fps on a GoPro works out well, both slo-mo and normal speed. With my new iPhone 6, 120fps works well also, but 240fps in a 30p Timeline gets messy. Only if I'm shooting a purposefully slo-mo shot will I use 240fps, as I'm conforming it and getting in-camera actual frame for frame slow motion. But at 30p, it is messy.

Hi JM1,

When you edit 60p material into a 25p project in FCPX (like in most NLEs) it gets automatically converted. The purpose of this conversion is to maintain the timing, so that 1 second in the source material, corresponds to 1 second in the project where you edit it to. That's what the "100%" speed percenteage represents if you show the Retime bar (Command+R).

The default method consists in either eliminating frames (when the source has a higher frame rate than the project) or duplicating frames (when the source has a lower frame rate than the project). That's exactly what the "Normal" Video Quality setting does in the "Retime Menu".

This method only works well if you are converting formats with a round multiplication or division factor:

- For example 50p to 25p (50p / 25p = 2). 1 out of every 2 frames gets eliminated for a seamless conversion. Since the frames are skipped in an even cadence across the whole second, you won't see any stutter motion.

- But that's not the case with 60p to 25p (60p / 25p = 2,4). FCPX can't eliminate 1 out of every 2,4 frames, because you cannot have anything smaller than a frame with video. Therefore, the frames will be eliminated in a random uneven way. That's why the motion isn't as fluid, because you get missing frames every now and then, not in a constant manner.

The fix for this would be to use a different method for the conversion. Unfortunately, as of version 10.1.4 you cannot select a clip at 100% speed and set its Video Quality to "Frame Blending" or "Optical Flow" (in the Retime Menu), which would get you a much better result. So I'm afraid that you are stuck with stutter motion.

In my opinion, this is a very serious issue and a highly important feature request to make. Specially now with HD and UHD that we are mixing frame rates much more often than back in the days of SD.

Avid incorporated this feature a long time ago with "Mix & Match" (it's called "Motion Adapters" in recent versions), and it basically consists on using the Timewarp effect (the equivalent to FCPX's retime menu) to convert between different frame rates, allowing the editor to pick the processing method.

FCP7 was not very good at converting temporal resolutions (and I don't believe Premiere Pro is either). This could be a great addition to FCPX, specially since the tools are already there (frame blending & optical flow).

I'm going to make a feature request for this right now. Hopefully we'll get it in future updates. Sorry I could't be of more help. Best of luck!

I found the solution!!!!

Forget about feature requests, we already have that feature!!

It's called Rate Conform!! You can read all about it in this documentation from Apple:
support.apple.com/kb/PH12648

The only thing you need to do is:
- Select all the 60p clips in the timeline.
- Open the Inspector and go all the way to the bottom.
- There, under "Spatial Conform" you will find a setting called "Rate Conform", which (unlinke Spatial Conform) only appears if the clip has a different frame rate than the project. That's why I missed this!
- There you can choose several options. My recomendation is that you try first with "Frame Blending". If the result you get is not as good as you want, go all the way for "Optical Flow", but be aware that this option will take more analysis and render time.

I didn't know about this gem! And now I do thanks to you!

Well, I hope you find it as useful and awesome as I do.

Happy editing!