Slow Motion but Lip Synced Music Video Technique

J

Jungle Media

Don't Stalk Member
Hey guys, Im' shooting a music video in a couple weeks and I have always wanted to try out this technique, where the video appears to be shot in slow motion, however the singers lips are perfectly in sync.

I'm going to do some test shots today.. I think I get the basic concept. If i want the video slowed down say 50%, then I need to speed up the music by 50% and have the singer sing along to that sped up version of the song...

so theoretically, if I shoot at 60 frames, I can just slow it down by 50% in FCP and make it 30 frames a sec and that'll make it perfect right?

I have to admit math boggles my mind sometimes.. but it seems simple enough ha ha...

Also this sped up chipmunk music must be a pain to sing to, I can't imagine the singer really doing this but I guess thats how it is eh?

Anyways I'm just gonna try it and see how it goes but if anyone has any tips or advice it would be much appreciated!
 
When you speed the music up, you can drop the pitch to sound somewhat normal and not chipmunkish... good luck, i want to try this too
 
well for those interested, i really messed that one up for sure. we were using a dvx100 and there was no option for 60frames but i figured it didnt matter as long as i slowed it down by 50%. so what i did is take a song and sped it up by 50% in a program called Audacity, then filmed me singing along to it. then imported this video into FCP, and slowed the video down by 50%, line it up with the original audio track... but it didnt sync. i must have done something wrong because the lips werent synced, it was too slow.

i'm guessing it has something to do with not having the 60frame option but i figured as long as i decrease by 50% it should still work. i dunno i must missing some strategic piece of the puzzle here...
 
i really suggest you make sure you can rent something that can do 60 frames, preferrably progressive and not interlaced. As I understand you really need the extra frames to make it not seem juttery when you slow it down.

I would film at 60p, conform to 30p or even 24p, and pre-calculate your sound in Audacity based on that.
 
Jungle Media said:
well for those interested, i really messed that one up for sure. we were using a dvx100 and there was no option for 60frames but i figured it didnt matter as long as i slowed it down by 50%. so what i did is take a song and sped it up by 50% in a program called Audacity, then filmed me singing along to it. then imported this video into FCP, and slowed the video down by 50%, line it up with the original audio track... but it didnt sync. i must have done something wrong because the lips werent synced, it was too slow.

i'm guessing it has something to do with not having the 60frame option but i figured as long as i decrease by 50% it should still work. i dunno i must missing some strategic piece of the puzzle here...
Click to expand...

Your math was off. If slowing the video to 50% in post, you need to have the music speed doubled during production. That's an increase of 100%, not 50%.

What's your end-target? Internet? TV? DVD? You might want to re-think your workflow.

You can shoot for 30p, if you aren't concerned about the film-like motion of 24p. In that case, shoot 60i (on the DVX, Progressive "OFF") for your slow-mo shots and use CinemaTools to conform it to 30p. That will create your half-speed slow-mo.

If shooting in 24p, you have a couple of options. You can shoot 30p and conform it to 24p in CinemaTools, for a playback of 80%. Or, you can shoot 60i and conform it to 24p for a playback of 40%.

As for calculating speed conversions, Barry Green had a great chart in the forums at one point... can't find the original, but some one pasted it here: http://dvxuser.com/V6/showthread.php?p=1185431
 
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Here it is

Here it is

found it:
Barry_Green said:
The problem with giving exact answers is that the frame rates aren't exact, so even if someone comes in with the magic formula it'll still have to be tested to be sure.

But, with that said, the basic formula is that you first want to determine your footage playback speed, and once you know that, it tells you how to modify the song. So (in theory) if you're wanting to shoot 48fps slow motion for a 24fps timeline, you'd be getting 2:1 slow motion, so you'd have to speed up the song so that it plays for exactly half as much time as normal.

So again, in theory, you'd take a four-minute song and speed it up so that it plays for exactly two minutes. Then you'd set the HVX into 24pN mode, set your frame rate to 48, and play the sped-up song and have your actor/singer lip-sync to the super-fast version of the song. Then when you play your footage back it'll be in 2:1 slow motion, and you'd marry that version of the footage to your original song, and they should now be in perfect sync.

But they won't be. Because there's theory, and there's this troubling thing called "reality," and the reality here is that the frame rates are not what they say they are. 24fps is not, for example, 24fps; it's 23.976. And 48fps is not 48, nor is it 47.952 (as you might think, if it's twice as fast as 23.976)! It isn't. It's actually 48.17. And 12fps isn't 11.988, it's 12.26. Except if you're on the PAL HVX, where it actually is 12.500, half of 25.000.

So you need to adapt the formula to comply to the actual frame rates. Fortunately the HVX does part of that work for you, by doing the 24pN (or 25pN) conversion in-camera, so we only have to concern ourselves with how much to speed up the song by.

I haven't tested these, but I'd guess they're accurate; if anyone tests them and finds them inaccurate please let us know.

For an NTSC/US HVX, using a 24p timebase, for the following frame rates, adjust the song speed to:

12 fps: make song last 1.956x longer by stretching it to 51.1% speed
18 fps: make song last 1.333x longer by stretching it to 75.0% speed
20 fps: make song last 1.226x longer by stretching it to 81.6% speed
22 fps: make song last 1.067x longer by stretching it to 93.7% speed
26 fps: make song last 0.907x as long as normal; play it at 110.25% speed
30 fps: make song last 0.800x as long as normal; play it at 125% speed
32 fps: make song last 0.747x as long as normal; play it at 133.87% speed
36 fps: make song last 0.672x as long as normal; play it at 148.81% speed
48 fps: make song last 0.498x as long as normal; play it at 200.80% speed
60 fps: make song last 0.400x as long as normal; play it at 250.00% speed

For an NTSC/US HVX, using a 30p timebase, for the following frame rates, adjust the song speed to:

12 fps: make song last 2.445x longer by stretching it to 40.91% speed
18 fps: make song last 1.667x longer by stretching it to 60.00% speed
20 fps: make song last 1.533x longer by stretching it to 65.23% speed
22 fps: make song last 1.333x longer by stretching it to 75.01% speed
24 fps: make song last 1.250x as long as normal; play it at 80.00% speed
26 fps: make song last 1.134x as long as normal; play it at 88.22% speed
32 fps: make song last 0.933x as long as normal; play it at 107.14% speed
36 fps: make song last 0.840x as long as normal; play it at 119.05% speed
48 fps: make song last 0.622x as long as normal; play it at 160.73% speed
60 fps: make song last 0.500x as long as normal; play it at 200.00% speed

For the Euro/PAL camera it's different; the timebase of PAL footage is 25.000 fps, so that makes it easier. But the other frame rates may vary, so it needs some calculation too.

For the PAL/EU/AUS/NZ cam, set the recording mode to 720/25pN, then set your frame rate to whichever your chosen fps is. Then adjust the speed of the song according to this table:

12 fps: make song last 2.000x as long as normal; play it at 50.00% speed
18 fps: make song last 1.400x as long as normal; play it at 71.44% speed
20 fps: make song last 1.266x as long as normal; play it at 78.96% speed
23 fps: make song last 1.080x as long as normal; play it at 92.60% speed
27 fps: make song last 0.920x as long as normal; play it at 108.68% speed
30 fps: make song last 0.840x as long as normal; play it at 119.04% speed
32 fps: make song last 0.778x as long as normal; play it at 128.56% speed
37 fps: make song last 0.680x as long as normal; play it at 147.04% speed
48 fps: make song last 0.520x as long as normal; play it at 192.32% speed
50 fps: make song last 0.500x as long as normal; play it at 200.00% speed
Click to expand...
 
oh. 50% slow down on the video means 100% faster song. that's where i messed up. thanks guy, I'm gonna test again today and see what I can do!

thanks for quoting the barry green chart too.. one thing i dont get about that, when he says the frame rates for if using a 30p timeline, but doesnt giving filming in 30p as one of the frame rate examples. hm...

anyways, off for another embarrassing round of air band! ha ha
 
Jungle Media said:
thanks for quoting the barry green chart too.. one thing i dont get about that, when he says the frame rates for if using a 30p timeline, but doesnt giving filming in 30p as one of the frame rate examples. hm...
Click to expand...

And that would be due to the fact that, when using a 30p time base, shooting at 30p is equivalent to 0% playback speed change. There's no need to list that. The chart is for over/undercrank calculation and is cited in terms of the HVX200, which has multiple frame rates. Again, with the DVX, you are limited to 60i, 30p, and 24p.

But using Cinema Tools, or a combination of Cinema Tools and Compressor, to conform 60i to either 30p or 24p can give you a very smooth simulation of overcrank.
 
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Okay I re-tried it and it worked perfectly! Sweet!

I am definitely going to try this effect on the music video we shoot in a few weeks. I'm so excited! It's gonna be wicked.

I found one example of this being done in an avril lavigne video: http://www.youtube.com/watch?v=bW2LTnzD-vE

Does anybody know any other videos that use this technique? I'm trying to explain to the singer how its going to look so some examples would help.

Thanks again for your help guys!
 
Definitely going to need a 60p or faster camera like an HVX200 or an EX1. A stock DVX100 won't cut it for more than a few quick shots. Well not without looking kinda cheesy in post that is... :engel017:

Noah
 
Actually we're going to be using the Red! but we wont have it till the day of the shoot so I can't practice on it :(

I filmed at 30p and just used FCP to put it at 50% speed. Would I do the same thing on Red or is it better to shoot at 60frames with that?

I guess I'm a little confused what I would do in that situation...
 
Jungle Media said:
Actually we're going to be using the Red! but we wont have it till the day of the shoot so I can't practice on it :(

I filmed at 30p and just used FCP to put it at 50% speed. Would I do the same thing on Red or is it better to shoot at 60frames with that?

I guess I'm a little confused what I would do in that situation...
Click to expand...


If you can overcrank, overcrank. That means shooting at a higher frame rate if it is available to you. Refer back to the chart to figure out how to alter the music playback depending on your particular frame rate.
 
my director is saying we should use 30p for the final frame rate because thats what they play on tv anyways so 24 would be pointless...

if thats the case, then when we use the red i guess we would film in 60 frames. then it would be the same thing, i just decrease the speed by 50% in FCP right?

found another perfect example of the technique in Mariah's Touch My Body video

http://www.youtube.com/watch?v=CzxR8OH-fDQ
 
Jungle Media said:
my director is saying we should use 30p for the final frame rate because thats what they play on tv anyways so 24 would be pointless...
Click to expand...

That's nonsense. Yes, broadcast runs at 29.97, but that doesn't mean that you can't produce at 24p. You'll just have to add the pull-down in before mastering to broadcast tape.

With 24p, you get filmic motion. The only thing 30p has in common with 24p is the "p." As far as motion, it looks very much like video.
 
boy am i glad i started this thread... ha ha. i know it has been asked before but this helps me out a lot.

I assume you are saying that if I produce a file with 24p timeline and then take it to be converted to betacam sp for sending to television, they will take care of the pull down issues and all that right?

so 24p it is. so i'd use 48 frames on the Red.

According to Barry's chart, if i film in 48fps for using a 24p timeline, i need to play the song at 200.80% speed.

I just converted the song as a test. At 200.80% speed, the words are totally incomprehendable!

it must be 100.80 % i'm supposed to speed it up by... i'm just confusing myself now...
 
Jungle Media said:
I assume you are saying that if I produce a file with 24p timeline and then take it to be converted to betacam sp for sending to television, they will take care of the pull down issues and all that right?
Click to expand...

Well, depends on who "they" are. Shoot and edit in 24p. Final Cut Pro can add the pull down in as it exports. Or you can export your 24p master file and use Compressor to convert it to 29.97.

Jungle Media said:
According to Barry's chart, if i film in 48fps for using a 24p timeline, i need to play the song at 200.80% speed.

I just converted the song as a test. At 200.80% speed, the words are totally incomprehendable!

it must be 100.80 % i'm supposed to speed it up by... i'm just confusing myself now...
Click to expand...

48 is to 24 as 60 is to 30, so you'll use the exact same adjustments as you did in your test earlier. Shoot with the song at double speed for a half-speed slow-mo edit.

What Barry's chart says is that you play the song at 200.8%. That means increasing the playback by 100.8%.
 
C2V said:
48 is to 24 as 60 is to 30, so you'll use the exact same adjustments as you did in your test earlier.
Click to expand...
Well, depends on what camera you're using. If you're using an HVX200, HPX170, HPX500, or HPX300, you wouldn't just double the speed, it wouldn't work! Look at the chart. 48 fps is not twice the speed of 24fps.

If you're using some other camera, you'll have to figure out what the proper speeds should be; this chart was specifically done because of the slightly off speeds of the HVX's frame rates.
 
Thanks so much C2V.. really appreciate your help, seriously. Pretty sure I got it now.

I had sped the song up by 100% earlier but now I know to make it 100.80% to be even more precise.

damn i'm excited about this video!!! cant wait to share it with you guys!!
 
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