lip syncing at different FPS for MV

April 5, 2006

hi,

I was wondering how do you slow down or speed up muisc so when you shot at 12fps or 40fps you can still lip sync the words? How do you know how slow or fast the song has to be to match the frame rate?

cheers

Gordon Highland · April 5, 2006

You could burn your own CD after using a workstation to change the speed. So if 24fps is "normal," then 12fps undercrank results in 200% speed of the song to maintain playback sync, and that's what you tell your audio software/plugin. Or 60% speed for 40fps, etc. At low speeds, the samples will break up and have a stuttering sound when done digitally, but it shouldn't be a problem for performance. Make a disc with several different speeds and label the tracks with their respective frame rate.

April 5, 2006

Is there a mathematical formula to working this out?

What if I wanted 33.333fps for a HMI safe shutter speed?

Gordon Highland · April 5, 2006

Well, undercranking makes the action appear fast, and overcranking makes it slow, so apply the same percentage that you deviated from 24fps (100%) to the music clip speed. < 100% is slower and > 100% is faster.

24 divided by 33.33 equals 72% speed, right?

Dan Salzmann · April 5, 2006

If the singer is singing at a faster rate, he or she should have a copy of this well in advance to practice lip-syncing to.

Make sure those mags are loaded on set because film can really fly through the camera.

BritLoader · April 5, 2006

check out the promo for 'Adore' by the smashing pumkins

the whole video plays out in one smooth dolly shot (all at one speed), but with a contantly varying frame rate, all done in sync. the result is a mix of crazy eratic movemnt and beautiful slow mo stuff.

Logically it means a complete syncing of dolly movement (presuambly mo-co), fps and shutter ramping and playback speeds. It seems too perfect to be syncrynised by hand, so it makes me think that there must be kit available that can co-ordinate al three elements.

I know on the Pumkin's DVD there was discussion by the director and I think the DP, however my copy of it went walkies a long time ago.

I'd love to know the technical method that they employed to sync everything. Anyone?

Phil Rhodes · April 5, 2006

Hi,

That's going to be tricky. I suggest that the best way to do it would be to shoot it all at a high frame rate (if you can find a mag big enough) to an audio track you've prepared in After Effects, then copy the speed curves (somehow) from the audio track into a time remap track, preferably something using active interpolation like Twixtor. That way you could get your audio and visual speed changes in precise sync.

I can't think of a way of doing it with actual speed ramping that wouldn't involve custom electronics, whether you shot it on a Varicam or on film.

Phil

David W Scott · April 5, 2006

A friend who directs music videos always uses his PowerBook for the on-set music playback. (Hooked up to a big Peavey speaker of course.)

He lays down the music track in Final Cut Pro. That has a number of on-set advantages -- it's easy to jump around to markers set on the timeline, there is no waiting for a CD player to spin up, and he can quickly set a playback speed in percentage. You just calculate the rate needed for a shot, i.e. shooting at 48 fps, set the playback speed to 200%.

Gordon Highland · April 6, 2006

shooting at 48 fps, set the playback speed to 200%.

Ah crap, did i just get all the math backwards in my previous posts? My brain hurts. I'm think I got the on-set playback and post-production sync mixed up. You ultimately want the song at its natural speed in the final version, right? 100% at 24fps? So when you shoot overcranked in slo-mo, you need to speed up the song on set by the same percentage, not its opposite. So sorry, guys. Arrrgh!