GH2 Mixing 24p and 30p in premiere, need help!

T

Tass

Active member
Hey all!

Ok so I might have screwed something up pretty bad today... I have shot a project in 24p, but some parts were shot in 60 p in order to make slow motion out of it (it is a part where a girl sings, the music was at 200% speed in order to make the 60p footage 50% slower and get real time speed while everything is in slow motion). So far so good, but now when I'm editing in premiere I notice that the 30p footage looks really not that smooth on the 24p timeline. So I tried the slow mo material on a 30p sequence and it worked, but now the 24p footage looks really unsmooth! I know that I should lower the speed to 40% to get 24p but the her singing gets out of sync, so it must be 30p.

Right now I'm editing the whole thing in 1080 60p, and that makes it all (as far as I can tell) really smooth, and I tried to export it in 1080 60p and it looked allright... So, can I stick to a 1080 60p sequence and export it in 1080 60p without loosing any quality or frames? Or will it look like it was shot in 60p and therefore loose the "24 cinema look"? The video will be shown on Youtube / Vimeo...

Is there any better way to solve this on, I really need help on this one!
 
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Well first of all you cannot have 60p with web video currently so both Vimeo and YouTube will convert to 30p. You may have to live with one of the formats not looking as smooth. Either stick with 24p so that material looks good or stick with 30p so the 30p stuff looks correct.

Another option is to to convert the 30p material to 24p with a really good retimer like the one in After Effects.
 
I've read the original post three times but I'm still confused (not an unusual occurrence for me though), anyway . . .

While I can't see the footage I'd bet it's a fifty percent chance that 24p frames not being smooth are strobing or judder from panning a bit too fast (pure speculation on my part).
What I don't get is the part about trying to sync someone singing to a slo-mo shot . . . can you explain what you're trying to achieve?

Regarding Premiere Pro, the current (and last few) versions permit you to mix multiple formats in the same sequence seamlessly.
I just edited (as a favor, I don't do weddings) a friends wedding where they threw footage at me from an AF100 1080/24p, TM700 60p, Hero2, iPad (where the shooter held the iPad up, rotated 90 degrees the wrong way), and a couple other miscellaneous cell phone. Was a nightmare but worked out thanks to Plural Eyes to sync it with. Point being Premiere (CS6 on a PC) made it easy.
(Grading is another story but given what I had to work with, the final wouldn't win any awards but was acceptable).

There was slow-mo shots in the project as well (created by cutting the desired piece out then adjusting the frame rate), but of course we weren't trying to lip sync it.

Something you might want to look at is frame blending (can't remember if that's the default or not), I find that for a lot of 24p work I've enjoyed better results with blending OFF . . . Your mileage may vary.

Best.
 
dregenthal said:
I've read the original post three times but I'm still confused (not an unusual occurrence for me though), anyway . . .

While I can't see the footage I'd bet it's a fifty percent chance that 24p frames not being smooth are strobing or judder from panning a bit too fast (pure speculation on my part).
What I don't get is the part about trying to sync someone singing to a slo-mo shot . . . can you explain what you're trying to achieve?
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I simlpy decided to film it in 24p in order to achieve a more cinematic look. One part of it was going to be a girl singing in slow motion, so in order to make her sing in slow mo while the music had the correct beat was to speed up the music for her to 200% and then I would simply make the 60p to 30p i Premiere and everything would be OK. BUT! I forgot that the other material was shot in 24p, and they don't mix well (not at all actually).... And if I speed the 60p footage down to 24p by doing 40% slow mo, sure that works but the lip sync isn't correct then, she simply sings to slowly since she lip synced to a beat that was supposed to be slowed down with 50%...

Understand my issues a bit better now? =)
 
Tass said:
the music was at 200%
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That's where you messed up. 60p slowed down to 24p is 40% slow motion. So the music should have been sped up such that slowed down to a matching 40% would be 'real time'.

You won't get good results going from 30 to 24, so skip the 30 entirely.

You will need to reshoot.
 
Jim Simon said:
That's where you messed up. 60p slowed down to 24p is 40% slow motion. So the music should have been sped up such that slowed down to a matching 40% would be 'real time'.

You won't get good results going from 30 to 24, so skip the 30 entirely.

You will need to reshoot.
Click to expand...

Or deal with the slightly jerky conversion of 30p to 24p or use a good retimer such as the one in After Effects or a third party plugin. With a good retimer it can actually do a pretty decent job converting 30p to 24p with pretty good frame accuracy. I have done it before. Yes it isn't perfect but neither is doing a reshoot which may be virtually impossible. If you have a lot of movement or randomly moving details in the background you may get weird artifacts but if the 60p is just of a singer than you may get decent results. Good retimer tools are not just for slow motion. They can also be great for doing framerate conversions. Yeah slow but if you have no other option it beats the pants off of frame blending.
 
Tass said:
I simlpy decided to film it in 24p in order to achieve a more cinematic look. One part of it was going to be a girl singing in slow motion, so in order to make her sing in slow mo while the music had the correct beat was to speed up the music for her to 200% and then I would simply make the 60p to 30p i Premiere and everything would be OK. BUT! I forgot that the other material was shot in 24p, and they don't mix well (not at all actually).... And if I speed the 60p footage down to 24p by doing 40% slow mo, sure that works but the lip sync isn't correct then, she simply sings to slowly since she lip synced to a beat that was supposed to be slowed down with 50%...

Understand my issues a bit better now? =)
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Yes I think so . . . probably having difficulty conceptualizing (in my mind) the point of syncing the voice (given what that will sound like in slow motion). Maybe you over-thought the process . . . I "think" what I might have done is to shoot everything at 24p so that your audio is locked to the video, then trim the clip you want to slow down and right click on it in the timeline and set it to 40% or whatever your choice target would be. You would simply have to live with the result but at least you will have overcome any sync issues. There may be other ways but this might be the simplest . . .
 
Oh boy do I wish that I could do a reshoot, but that is not possible in any way... The thing is that this was my first time shooting at 24p, usually I work with 25p and 50p for slow mo, so I simply didn't think it through all the way. Oh well, thank God that this is such a small part of the video and not the majority of it! I will try every single way there is and then pick my poison!
 
Perhaps transcoding all the footage to the same frame rate before importing to editor; i.e. 24p/Cineform, DNxHD, etc.?

I don't know if this would help/it certainly wouldn't hurt as long as you save the original clips and transcode/'save as' a new file.
 
To help, you might get away with changing the speed of the song slightly (while maintaining pitch) without anyone noticing. And the result doesn't need to be exact. Cut away when it starts to get out of sync and then return. It could ramp down just before the slow-mo and ramp back up.
 
Jordan_S said:
To help, you might get away with changing the speed of the song slightly (while maintaining pitch) without anyone noticing. And the result doesn't need to be exact. Cut away when it starts to get out of sync and then return. It could ramp down just before the slow-mo and ramp back up.
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That's sound really crazy, but could actually work, and hope for the best that the client won't notice =P!
 
Tass said:
I actually do have Twixtor on this computer, haven't given it much thought... I mean, even if I make the slow mo in Twixtor, I still will have a 60p or 30p clip rendered together with 24p, either way one of the formats will be suffering... Right?
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That is what I have been posting about on here a couple of times now. A good retimer isn't just for slow motion and can be used for frame conversion. Basically think of it as the retimer converting your 60p to a higher framerate which 24p can be divided evenly into like 120p or 240p. Once it does that the conversion to 24p will be much smoother. Twixtor and the retimer build into After Effects can do this very well. I have converted footage shot at 60i by accident to 24p. Yeah camera flashes and complex motion may get a little funky at moment but it beats doing a crappy frame blending conversion. This is the best chance you have of getting it to look somewhat decent outside of a reshoot. Since your footage is a singer and I will assume doesn't move a lot you should get very good results albeit very slow render time.

Basically the reason why your current conversion looks like kaka is that you cannot divide 30 into 24 and get clean whole frames. Even 60 doesn't get you a clean division into 24. By having a plugin create a virtual 120p or 240p you now have a number of frames that can be divided evenly into 24. The motion should look very close to native 24p as long as the motion isn't to complex and the plugin struggles to predict the virtual frames.

Just listen to me and try it. If that doesn't work then you are SOL.
 
Can't make it look good in AE, too much motion going on behind her and stuff... BUT! I'm not totally SOL just yet! Thing is that it has to have a retro look to it, so with some vintage grain / flares it almost looks like it should be there... So... I will cover it up with some nice Gorilla Grain and live with it... Man I will never do this stupid mistake again what the hell was I thinking on =P
 
Tass said:
Can't make it look good in AE, too much motion going on behind her and stuff... BUT! I'm not totally SOL just yet! Thing is that it has to have a retro look to it, so with some vintage grain / flares it almost looks like it should be there... So... I will cover it up with some nice Gorilla Grain and live with it... Man I will never do this stupid mistake again what the hell was I thinking on =P
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Yeah if there is a lot of movement behind the singer then twixtor may not work any better either. Overlapped motion starts to get a bit funky. It was worth a shot. Good to hear that you can kind of cover it up with clever use of color and grain. Of course it isn't perfect but all of us tend to be a lot more critical of framerate conversion flubs than most other people.
 
Thomas Smet said:
Yeah if there is a lot of movement behind the singer then twixtor may not work any better either. Overlapped motion starts to get a bit funky. It was worth a shot. Good to hear that you can kind of cover it up with clever use of color and grain. Of course it isn't perfect but all of us tend to be a lot more critical of framerate conversion flubs than most other people.
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Yea, I had huge luck this time.. But to be sure to never make the same mistake again.. At what speed should the playback music be in order to get synced 24p when slowing it down from 60p with 40% speed? I know that with 50p slow mo the music should be at 200%, but what percent is it when doing 60p to 24?
 
Tass said:
Yea, I had huge luck this time.. But to be sure to never make the same mistake again.. At what speed should the playback music be in order to get synced 24p when slowing it down from 60p with 40% speed? I know that with 50p slow mo the music should be at 200%, but what percent is it when doing 60p to 24?
Click to expand...

250%
 
Tass said:
Can't make it look good in AE, too much motion going on behind her and stuff... BUT! I'm not totally SOL just yet! Thing is that it has to have a retro look to it, so with some vintage grain / flares it almost looks like it should be there... So... I will cover it up with some nice Gorilla Grain and live with it...
Click to expand...
Time to make use of layers and some roto mattes then. IE often a frame blend of the background with a Twixtor-ed foreground person using pretty loose and soft mask can work wonders.
 
I have abandoned premiere in favor of Edius & Vegas 12 which can support mixed frame rates. No online streaming service except LIVESTREAM currently plays 60 or 60p. I was able to switch in ONE file back and forth while shooting but I must edit in vegas if I want to keep it that way otherwise it gets converted to something.

Check it out for yourself you'll have to download the clip to see it - it also really shows the psychological effect of the film look vs live like by switching back and forth within the same file, same shot as it plays. Only 720p 60p was too big - you have to DOWNLOAD it and play - vimeo converts it to 30p.

http://vimeo.com/michaelbiggins/filmlookvslivelook

- Blackout
 
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