Converting 23.98fps HD to 25fps for PAL DVD

[Will Hodgson]

Hi Tim,

You could change the meta data of the clip so that it plays back at 25fps in Cinema tools. The footage will still be in HD, but then you can compress that using Compressor without changing the frame rate.

The picture and audio will be ever so slightly sped up, but Iunderstand that this what is done to get 24fps feature films into a 25fps PAL friendly format.

Will

As I wise man once said after an all night edit, I hate this shit!

[Sean Oneil]

Use Cinema Tools and conform it.

Sean

[Nick Meyers]

“this what is done to get 24fps feature films into a 25fps PAL friendly format. ”

that’s true, but these days they pitch correct the audio using the best processors available.

nick

[Tim Mclaughlin]

So what is the “poor man’s” version of the best processors available?

Tried both Soundtrack Pro and Audacity. Both were able to adjust “tempo” without adjusting pitch, but fell out of sync quickly – so something is off with the math there.

Anyone have a “tried-and-true” percentage for fixing this?

And do PAL viewers really watch “The Dark Knight” 4% faster than the rest of the world? I think the director would be kinda ticked about that.

Tim McLaughlin
Avid and Final Cut Editor

[Nick Meyers]

Final Cut Pro has a pitch shift filter in it.
it’s really bad, but i dont think it goes out of sync.

the controls are pretty hard to work out (there’s the obvious “Pitch” slider, then about 50 other things, that no-one knows what they do!)
best way to figure out the settings is to export some bars & tone & Confomr them in CT.
bring them back in, and lay them up agasint some true 25fps tone in a PAL sequnce.
apply the pitch shift to your conformed file and experiment with the pitch slider.

yes all PAL viewers watch telecined films 4% faster…
as do a lot of cinema viewers!
cinema managers like to speed up their projectors to A) minimise lamp time, and B) maximise popcorn buying time.

nick

[Tim Mclaughlin]

Okay folks – here’s what I’ve learned:

Step 1:
Dupe the file in question and label as “25fps”.
Otherwise, Cinema Tools will “conform” over your existing 23.98 file.

Step 2:
Use Cinema Tools to conform the file to 25fps. This will translate the file to 25fps, slightly speeding up the file (roughly 4 %). A slight change in pitch can be noticeable, depending on content.

Step 3: (not required, but I recommend it)
Use QT Pro to export a 48k AIFF of the newly conformed file. Load the AIFF into Audacity (or your choice of audio editor) and pitch-shift the file to play 4% slower. Export this new file with a “pitch” tag in the file name for the sake of sanity. Audacity did a surprisingly clean conversion, I was very happy.

Step 4:
Run the conformed QT (and pitch-shifted AIFF) through Compressor. Load ’em into DVDSP and make your new PAL DVD.

Now admittedly, this is not the work flow for everyone. Many would argue that it would be best to pitch-shift the audio file before conforming, etc. And in checking with some of my European resources, I’ve been told that many programs aren’t adjusted for pitch, they simply run with the 23.98 to 25 conversion and are done with it.

Also, conforming this way does speed up your video about 4% (ie: a 100 min program is only 96 min log after conforming).

However, with this method, a frame is mapped to a frame. You are making a true 25p DVD, no frame-blending, no interlacing. And by adjusting the pitch of the audio AFTER the conform, you won’t need to worry about audio sync issues – the file duration is still the same, you’re merely pitching it a bit.

Conforming is near-instantaneous. And exporting and pitching the audio takes only a couple of minutes.

Without jumping through a bunch of hoops, this is a very quick an easy way to get your HD content to PAL-land.

Tim McLaughlin
Avid and Final Cut Editor

[David Jardine]

Hi, just wondering in step 4 – when using compressor, do you just use the default settings for DV PAL?

[Nick Meyers]

there aren’t specific PAL or NTSC settings for DVDs in Compressor.

i *think* it looks at the frame rate and figures out which one it is.

this has been working for me going the opposite way,from PAL to NTSC.
i was working on a feature where my rushes were PAL, but the frame rate “Conformed” to 24.
if we wanted an NTSC DVD, we just dropped our 24fps files into Compressor, and it made an NTSC Mpeg,
even though the frame size was still a PAL size.

nick

[Michael Gissing]

MPEX3 (which can be licensed in Pyramix or Nuendo or as a stand alone)does a great job of changing speed without pitch etc. 23.976 to 25 is 4.1%. 24 to 25 is 4%.

If you want a result that is best then send the aiff file to a sound pro with either MPEX3 or Pitch n’ Time. Audacity might do an OK job but us audio pros will hear it. If your show has music then not changing pitch will shift everything approx 3/4 semi tone sharp. Ouch!

[Tim Mclaughlin]

FWIW – Audacity did a fairly good job. But I’ll have to check on those plug ins.

And yeah – if you don’t pitch-shift, everyone sounds like Alvin-chipmunk’s little step-cousin. Slightly faster, and the music is a much quicker tempo.