# Help to convert 25fps to 24fps



## Xavb (Apr 27, 2013)

According to director requirements, I delivered music for a film (DVD) at 48k, 16bit and 25fps. Now, it seems that they found sponsor and potential theatre distribution and they would do the final mix in a 5.1 studio, which requires 24fps.

They can convert quite ok FX and dialogues, but I can hear the difference with the "converted" music. So I am thinking in opening again the projects (DAW Logic) and do all cues as new 24fps projects.

All 25 cues are just MIDI and big V.I. orchestration templates. So, I will have to remix everything again.. 

Is there any way to get around this conversion? How should I do it? Tempo/General track meant a lot of work. Can I copy it? How? Does the import "Global, Audio, Inst,…" from "Media/Browse" woks well for these conversions?


I would really appreciate any advice.
My very best
Xavier


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## Reegs (Apr 28, 2013)

Unless I'm missing a subtlety or you've encoded the timecode into your mix, why do the bounced wav files care what fps it is? It's still 48k I assume, and they haven't altered the running time? Bounce your tracks, open Vegas/Premiere/Final Cut and drop them at the right timepoint +/- one frame. Print the video, and done?


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## jaeroe (Apr 28, 2013)

Reegs is right. you're just talking about video/frame rate - which is just how many frames in a second for video. a second is still a second.

what you can do is just use what you have and output your stuff so your audio files always start right on a second - i.e. timecode ends :00 - and make sure it's time stamped that way. when people import your music for the mix the time stamp will be accurate, because an even second is always an even second. the different frame rates only vary between seconds.


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## gsilbers (Apr 28, 2013)

Best thing is to get a new video reference of what they want.

If its going to be released in theaters and need it for a dcp, they probably want 24 true filml frame rate which is a different SPEED than 25 and (29.97/23.98).

There is 3 main speeds in the audio world 25- 29.97(23.98) and 24 true film.

With that said , many people call 24 fps what it actually is 23.98psf thus better to get a video reference . 

If pitch is you issue you can do 2 things: 

Dont care about... Really, no one else will notice the audio shift be a few cents down. Not even you when it's played in theaters . 

Or you can use protools (daw) to import the mix and apply SRC which will take care of time and pitch. The template it has comes with the common varispeed from pal to NTSC /23.98 and film etc.


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## germancomponist (Apr 28, 2013)

gsilbers @ Sun Apr 28 said:


> If its going to be released in theaters and need it for a dcp, they probably want 24 true filml frame rate which is a different SPEED than 25 and (29.97/23.98).



So, a 90 minutes film in 24 isn't a 90 minutes film in 25? 

Without joking, you are right here, because they had stretched it from 25 to 24. So in this situation it is a different speed.


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## gsilbers (Apr 28, 2013)

germancomponist @ Sun Apr 28 said:


> gsilbers @ Sun Apr 28 said:
> 
> 
> > If its going to be released in theaters and need it for a dcp, they probably want 24 true filml frame rate which is a different SPEED than 25 and (29.97/23.98).
> ...



No. 

It's common to mix up the frame rates with the actual speed it's going at. 

We just think 29.97 per second a frame. And 25 frames per second and think its still one second , but if its 25 fps it's actually pal speed which 4% faster than NTSC video ( 23.98 or 29.97)

So pal it's clocked to 50hz and NTSC is clocked to 30 .

There are different ways of doing standards conversions. Some of them maintain the original speed others speed up for pal . It'll be 4% speed change so a 90 min would be a few min less and higher pitch by half a tone.

Everything you get in Europe from the us is 4% faster unless they keep 23.98 and not go to 50i in hd land.

24 is true film sped which if the work didn't start in 24 then I doubt it's really 24. If a project started in 25 then most likely they want 23.98 or like some like to call it 24psf which is not true 24 but a Fancy word for 23.98 which will be 4% slower than 25 and half a tone down in pitch.

Thus the best thing is to ask for a picture reference ofthe final.


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## germancomponist (Apr 28, 2013)

gsilbers, did you read my complete post? 

Maybe you wrote yours when I was editing mine?


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## gsilbers (Apr 28, 2013)

Haha sorry. I just read the quote . It didn't grab the second important sentence


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## germancomponist (Apr 28, 2013)

gsilbers @ Sun Apr 28 said:


> Haha sorry. I just read the quote . It didn't grab the second important sentence



Ha ha, I was too fast with reading the first post from Xavb. After I re-read it I edited my post. And this at the time when you wrote yours. 

Salut o-[][]-o


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## RiffWraith (Apr 28, 2013)

Reegs @ Sun Apr 28 said:


> Unless I'm missing a subtlety or you've encoded the timecode into your mix, why do the bounced wav files care what fps it is?



Because the bounced wav files aren't playing back at the same speed in PAL as NTSC, or vice-versa.



> I assume, and they haven't altered the running time?



Yes they have.

gsilbers is correct.

Xavb - there are two different ways to do this. First, redo your score with your MIDI as you alluded to (I know you said you are trying to avoid that) - just make sure you have a new video to work with. And make sure that that vid is at 24, not 29.97 (23.976). 

You can also stretch the final music to fit. The problem with stretching is artifacts - especially if you want to keep the same pitch. And you aren't just stretching a little. Nowadays, there might be algos that are suited for this - I am not sure. Remember that JW score (JPark?) that was slowed like a billion percent? Maybe look into that.

I remember in the good old days, we used to have to educate our clients on this matter.

_Why does the music sound like that? It sounds fekked up!_

Becuase it has been stretched.

_But it sounds bad - I dont want to do it that way._

That's the only way to do it.

_But it sounds bad - I dont want to do it that way._

Then you don't have a film.

_Oh ok - go ahead then._


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## Xavb (Apr 28, 2013)

thanks so much for all the answers

yes, they gave me a new vid at 24 and, indeed, 25 audio bounce does not fit with 24 image.
I hate to admit it but stretching the music is not an option. It is a noticeable stretch of rich harmonic orchestral music (half a tone!). I hate to have worked so hard in instrument EQs , reverb colour, etc and then to destroy all that with a Time Stretch.

I read somewhere that a trick is to record old 25track in a 24 project but not at 48Khz but at a higher rate (>50?), then the 24 project will playback slower the audio and the result is similar to the original 48/25. No idea what exact value is that and if it is worth.

So, I guess will have to copy all MIDI sequences and remix them.. augh! 25 cues…..


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## gsilbers (Apr 28, 2013)

Xavb @ Sun Apr 28 said:


> thanks so much for all the answers
> 
> yes, they gave me a new vid at 24 and, indeed, 25 audio bounce does not fit with 24 image.
> I hate to admit it but stretching the music is not an option. It is a noticeable stretch of rich harmonic orchestral music (half a tone!). I hate to have worked so hard in instrument EQs , reverb colour, etc and then to destroy all that with a Time Stretch.
> ...



really, its not that noticeable. almost every american show and movie ever in EU is half a tone up when it broadcasted. o[])


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## Xavb (Apr 28, 2013)

Thanks Gsilbers! I will try it


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## gsilbers (Apr 28, 2013)

i could swear SRC in PT had a setting to keep pitch. i cant see in PT9HD now.


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## Jimbo 88 (Apr 28, 2013)

I'm not seeing how changing the frame rate changes pitch. I can change frame rates in my DAW all day long and have. I'm suppose to get 29.97 Drop frame, but editors will send me different frame rates all the time. The mixers and i stay in touch and the only problem that will occur if I have wrong TC is the reels or segments will have to be re-synced. Because we are aware of the issue it is a 2 minute fix.

What should be done...as mentioned, get a new pic version with the correct TC. Load up your files and you'll have to correct the start times. The reason i will do this, and is only necessary is if the music is being delivered in TC stamped format like a broadcast wave or an OMF.

The most probable reason the music does not sound right to you is the Production company tried a short cut getting to the new Frame rate and did something like re-render the whole file to a new frame rate. Instead of creating a new pic file and laying back audio. 

Your music in its mixed form should time out really really close without messing with anything. It might need a tweak or 2, but this should not be your problem.


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## Jimbo 88 (Apr 28, 2013)

Changing frame rates should not have to stretch pic or audio if it is converted correctly.

A 5 min film should always be 5 minutes no matter what the frame rate, just how internal measurements are made. 

If you put a stop watch on a drop frame vs non-drop frame or other frame rates, the point where you "read" 5 minutes in the TC will be different. But no matter what the rate is the picture should time out the exact same.




_Edit> I'm re-reading my post and it sounds like I'm disagreeing with other posts. I am not. I'm pointing out that the Producer and the production people are really dropping the ball on you here._


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## RiffWraith (Apr 28, 2013)

Jimbo 88 @ Mon Apr 29 said:


> A 5 min film should always be 5 minutes no matter what the frame rate... .



Hold on.

A 5 min film will always be 5 minutes no matter what the TC or seqencer framerate is. 

A 5 min film shot at 24 will not be 5 min after being converted to 25.

Set your seq to 24. Load a 5 min vid shot at 24. That vid will be 5 min in duration. Now change the framerate to 25. That vid will still be 5 min in duration, because you have only changed the framerate of the sequncer - you haven't done anything to the vid. The vid doesn't care what the seq is set to; time is time.

If you convert the vid from 24 to 25 (or vice versa) the duration will change.

Another way to look at it:

Load a vid shot at 24 into your seq. Conform your audio to that vid. It plays in sync. Then convert the vid to 25. Load that into your sequncer. Does the audio still play in sync with the vid? No - the vid's duration has changed. 

Cheers.


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## Jimbo 88 (Apr 28, 2013)

RiffWraith @ Sun Apr 28 said:


> Jimbo 88 @ Mon Apr 29 said:
> 
> 
> > A 5 min film should always be 5 minutes no matter what the frame rate... .
> ...




I get what you are saying and you are not "wrong", but you are not really "converting" a pic file in your example. You are playing back a 24 frame picture at 25 frames of course things will not time out. If i play a 48k wav file back at 44.1 I did not convert the audio, I'm just playing it back at the wrong rate. If I do "convert it" the wav will pretty much time out and sound correct.


The production company is cutting corners that easily do not need to be cut.


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## RiffWraith (Apr 28, 2013)

Jimbo 88 @ Mon Apr 29 said:


> I get what you are saying and you are not "wrong"...



No - I am actually correct. 



Jimbo 88 @ Mon Apr 29 said:


> ...but you are not really "converting" a pic file in your example.



Yes I am - I even said so:



> If you convert the vid from 24 to 25 (or vice versa) the duration will change.





Jimbo 88 @ Mon Apr 29 said:


> You are playing back a 24 frame picture at 25 frames of course things will not time out.



Right - that is exactly what I am saying.


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## germancomponist (Apr 28, 2013)

What do u notice if you change the speed? o/~


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## RiffWraith (Apr 28, 2013)

germancomponist @ Mon Apr 29 said:


> What do u notice if you change the speed? o/~



The earth starts to rotate faster.


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## RiffWraith (Apr 28, 2013)

germancomponist @ Mon Apr 29 said:


> What do u notice if you change the speed? o/~



The earth starts to rotate faster.


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## germancomponist (Apr 28, 2013)

RiffWraith @ Mon Apr 29 said:


> The earth starts to rotate faster.



o/~ o=<


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## Jimbo 88 (Apr 28, 2013)

So playing a 25 fps video back at 24 fps means that your 25 cues will all drift out of sync even within the individual cues and means a ton of work to fix.

I do not understand why someone would want to playback a film at the wrong frame rate when it is not a big deal to re render a new version with the new media playing back correctly at the desired fps.


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## Xavb (Apr 29, 2013)

I appreciate very much all your comments. Since I am starting to get lost I will summarise the facts and data:

1.- I went with the director to the mix studio. The studio is a certified Dolby Premier studio designed by Philip Newell. Top place and top engineer with years of experience in big films.
2.- The engineer told us that our 25fps track could not be used by the official system. It should be done at 24 (23,976) or CONVERTED.
3.- He said that dialogues and FX will be ok BUT that music will be transposed half semitone after conversion. He said that usually only musician will notice it.

4.- As some post here, I was chocked. I claimed that 1 second was 1 second and that I would deliver an audio file and it should fit with the image.
5.- The engineer said "no, it is not like this, sorry. Trust me, I have faced these kind of situations for years". 

6.- I asked for a 24fps Video to the Production Company and went to my studio to test it by myself

7.- Unfortunately, he was right. Audio does not fit AT ALL. It is a 90' movie and even if I start a particular audio cue at the right scene of the 24 version (ex. at the beginning of a love scene), the following hits of that scene (ex. eyes close-up, etc) do not fit.

8.- I tried to created new projects at 24 (usually I do a Logic project for each cue. I always write the full orchestra score, then record each instrument in Logic. Each music always start at bar 3,). I copied the MIDI files to the 24 projects. Big template, many, many MIDI sequences for each cue x 25 cues….

9.- and….. I am exhausted

I think I give up. I will do as Gsilbers suggests and just convert it. Drink some Rioja wine and hope for the best. Thanks, my friends.


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## Jimbo 88 (Apr 29, 2013)

All I can tell you is...I have worked with a lot of video editors that if you said, "hey we need this project in a different frame rate." they would reply "OK" and the next day there would be a new pic at the correct frame rate. The video editor would be embarrassed if elements did not sync.

Sorry to hear about your trouble. I see how it could be very frustrating for you. Good luck.


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## germancomponist (Apr 29, 2013)

Jimbo 88 @ Mon Apr 29 said:


> All I can tell you is...I have worked with a lot of video editors that if you said, "hey we need this project in a different frame rate." they would reply "OK" and the next day there would be a new pic at the correct frame rate. The video editor would be embarrassed if elements did not sync.
> 
> Sorry to hear about your trouble. I see how it could be very frustrating for you. Good luck.



Maybe it depends on the software they used to change the frames?


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## Steve W. (Apr 29, 2013)

Hi,

This might help to explain some of the questions in the posts above.

Without getting into too much details, there are 2 ways to convert the frame speed of a movie.
You can can either change the playback speed,
or you change the frames themselves.

Both have their advantages and disadvantages and are used depending on the situation:

If you change the playback speed you keep the original frames intact but the speed of the movie and the frequency/pitch of the the sound changes (as described in the posts above). This works for converting to frame rates that are very close like 24to25

If you change the frames you keep the sound intact but the different frames change.
There are several ways to do that from very simple algorithms like doubling or removing a frame every nth frame (this can result in a jumping of the movement) to very complex ones where whole image sequences are recreated to keep the movement smooth.
As you are changing the frames this also changes the look and feel of the movie (this can range from very visible jumps in the movement to almost unnoticeable differences)



Steve


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## gsilbers (Apr 29, 2013)

Xavb @ Mon Apr 29 said:


> I appreciate very much all your comments. Since I am starting to get lost I will summarise the facts and data:
> 
> 1.- I went with the director to the mix studio. The studio is a certified Dolby Premier studio designed by Philip Newell. Top place and top engineer with years of experience in big films.
> 2.- The engineer told us that our 25fps track could not be used by the official system. It should be done at 24 (23,976) or CONVERTED.
> ...



let me know if u would like me to do this for u. but its very simple though if u have pro tools. open a session in 23.98 and go to file> import file and select import audio file> choose convert and select SRC and next to it there is a drop down menu that tells you the common converisons, choose pal>ntsc and import. load the new picture and conform the new audio. (just spot it to where it starts and make sure it matches at the end. 
i used to do this all the time since i also work in the tech side of distribution and this is done daily hoards at a time. 

but i cant belive the producers/film guys started the project in pal. (same goes for ntsc) 
anyone reciveing a video that the master is pal or ntsc you should telll the director that its wrong and do 23.98 or true film. true film guys should already know. but 23.98 newbies might just want to master their video the broadcast spec 1080i50 or 1080i60 when they dont know that it is done after the 23.98 is completed and then a conversion is done. from 23.98 u can go anywhere. but in 50i you cant (easily) go to 1080i60 and distribution is where the money is, thus is short sighted to think its only going to be shown once in your local tv station or in small theatre. plus any VOD/internet will always be 23.98. even ntsc is deinterlaced.


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## sin(x) (Apr 29, 2013)

Xavb, the post world has pitchshifters designed to operate on 5.1 signals with phase coherency across all channels. Those are often used to compensate the pitch change after a PAL speedup (or slowdown). I've been using ZPlane's Elastique for this in the past with good results, but there are even more sophisticated tools for this task. Maybe the Dolby studio can help you out with this, too.


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## jaeroe (Apr 29, 2013)

does logic do pull-down/pull-ups?


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## sin(x) (Apr 29, 2013)

Yes, a "classic" pull-up or -down is nothing more than a resampling by 4% (so if you resample your 48k material to 46080 Hz and play it back at 48k, you got your typical PAL speedup). Logic can do that, but of course the pitch will change. I wouldn't trust Logic's pitchshifting or timestretching algorithms with compensating this; I tried that back when I was still a Logic user (Logic 8 I think?), and it ripped my 5.1 panorama apart with heaps of ugly phasing problems.


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## Xavb (May 3, 2013)

I wanted to tell you that Gsilbers was so kind as to do the conversions and that everything fits perfect with the new 24movie and they sound great.

I would like to express in public my deep gratitude


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