Hey,

I was wondering if someone could explain to me how to take 24fps footage and export a 25fps QT movie so that I can use it to create DVD's.

I have tried manually changing the frame rate of the QT file as it exports but this just adds a duplicate frame which causes a lag effect on the footage especially during motion. Is there a way to get the footage out by speeding up? I don't have a Mojo.

Is it as simple as adding a motion effect with a 4.1x speed change?

Have help would be much appreciated

All the best,
Ian

Hi Ian

Yes I agree there should be a simple way of changing the framerate of a video-only movie.  Perhaps in Quicktime Pro you can edit the metadata?  I'm not sure.

My workaround is to export to a targa stream then re-import into a 25fps project.  The audio resampling is done in audacity, imported into the same project and combined with the video for a new export.

Slow and expensive space-wise (especially if you're doing a whole feature) but it's the best option I've found so far.

Good luck
David

Nice Guy Dave:

My workaround is to export to a targa stream then re-import into a 25fps project.  The audio resampling is done in audacity, imported into the same project and combined with the video for a new export.

I do something similar, except that I use After Effects.

I export a QT ref file from Avid which simultaneously exports an AIF file of the audio.   I open that AIF in Audition, speed it up the by 104.17% and save it as WAV.   Next I open the WAV and the QT ref file in AE and interpret the video footage as 25 fps.

I drop both the interpreted QT ref and the WAV onto a timeline and mute the QT ref.  Render the lot to a suitable format and you're done.

The process with AE is slow, but it would have to be faster than the targa path if you have access to AE.  You could also do something similar with Premiere.  I've been told that you can also resample the audio in Premiere but I've never done that.

I've found that you can speed the audio up in avid using audio suite time compression plugin and it works fine for what I wanted to do. Though it certainly aint a mastering technigue.

This is indeed a workflow black hole for PAL film people. My workaround has been Cinema Tools on the Mac for some time as it has a conform to frame rate feature which will speed a 24fps QT up to 25fps. The only problem is that it won't work on a QT ref file, so you will need to export a self contained QT out of Avid and then process. It handles the audio speed also. Mac only of course.

Of course the easiest way to make quick 25fps DVD's is to playout of Mojo with Film options set to 25fps and use a set top DVD recorder. If you had a spare laptop with FCP on and a Canopus box, you could also playout of Avid at 25fps and capture direct to FCP and encode from there.

If Avid were prepared to use the full QT toolkit this could be accomplished direct inside the Avid software. QT files playback speed is simply determined by a few flags inside their track structure. You can look at this using a small tool like Dumpster:
ftp://ftp.apple.com/developer/Quicktime/Tools/Programmers_Tools/Dumpster.dmg

There is a really good tool which can do this with QT ref files, but it comes as part of a package for $99. The frame rate converter is a separate app, but the developer won't sell it separately, so its $99 for this solution.
http://homepage.mac.com/dvd_sp_helper/Commerical/DFT.html

--Mark

mark.burton:

My workaround has been Cinema Tools on the Mac for some time as it has a conform to frame rate feature which will speed a 24fps QT up to 25fps. The only problem is that it won't work on a QT ref file, so you will need to export a self contained QT out of Avid and then process.

Hi Mark,
I do that too when I need to make a DVD for instance. Export as Ref works, as long as you force the Avid to mix the tracks - which creates a new AIFF file in the export folder. Then you can batch conform the clips to 25 and it works perfectly. It's faster because only the sound gets processed when you export, and also it takes much less space.
Pierre

Hi Pierreh,
Thats odd. I have never had a QT Ref file convert between 24 and 25 in Cinema tools without getting strange results - usually after the first clip in the Ref file, the movie turns to coloured static.
The audio file is always mixed down though, so not sure how that makes any difference.

Can you explain what you mean by 'batch conform the clips' as surely you only have one QT ref file after the export?

Thanks
Mark

It seems that by using Dumpster you can alter only a few values in a Quicktime file to make it play at 25fps instead of 24fps. This way you can export a 24fps Quicktime reference file from Avid (much faster) and by making four value changes to the file in Dumpster (takes 20 seconds) it will now play with 1:1 frame acuracy at 25fps with audio also sped up to match. Perfect for making DVD's with no pulldown.

I made a quick webpage to explain this procedure for the Mac, see if it works for you:
Convert 24 to 25 Mac

--Mark

Great job! Thanks.

Can't change anything on file's metadata. Additionally, screenshot looks nothing like what I got (WinXP version) - see screenshot.

Does it only work on MAC's?

Sorry guys. I should have made that a bit clearer. I have updated the page to reflect the fact this was done with the Mac OS X version of Dumpster.

Although there is a Windows version of the app which should be able to do the same, its a bit more complex as it uses 'strings' to represent the values. I was able to find all the relative entries in the Windows version Dumpster apart form one - the sampleRate value in Sample Descriptions.

In order to change the values you need to know the equivalent string value to represent the number. For example for the timeScale value, $00000271 would equal 625.

I could not figure out what the string would be for 50000 and there seems to be a section not being displayed anyway, so it might not even be possible. Sorry about that.

--Mark

:( Thanks for updating the site, though.

mark.burton:

Can you explain what you mean by 'batch conform the clips' as surely you only have one QT ref file after the export?

Sorry, I should have mentioned that I often export many mini-sequences and therefore have quite a few QuickTime files in the export folder. Then I use the Batch Conform feature of Cinema Tools to convert all of them in one go.

Looks like you can use the Windows version of Dumpster to do this job. Its not as elegant as the Mac method, but still very quick and easy:
Convert 24 to 25 PC

--Mark