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Film at 24fps, telecine at 29,97, audio at 30. No sync.
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It was a Cantar. Audio set at 30NDF.
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Sorry, Cantar Audio at 48.000 TC 30 NDF.
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Tha audio is already separate from the video. It syncs if I convert it without TC but doesn’t if it has TC.
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Since it was the Cantar, I wonder if the setting was “C” Compensated (F) Faux mode. In this mode, the assumption is that the sound will be syncing with film converted to video rate.
The sound is recorded at 48048 samples per second, but it is tagged as 48000. This causes a .1% slowdown, perfect for syncing against film transfers at 29.97 or 23.97. However, if the sound was recorded this way, and then you have used reverse telecine to 24, the film is not slowed down.
However, the sound is slowed down due the recording mode used in the Cantar. Here’s the rather confusing way this concept is explained from page 15 of the 2008 Oct. 02 manual:
“The ‘C’ mode is made for challenged post-machines. In a
file digitized at 48kHz, the Format stamp value indicates the
real number of samples per real-second, i.e. 48000, and
the Time stamp is the number of samples since midnight as
if the digitization was done at 48048!
Hence the ‘F’ name (for Fake or Faux) given by Fostex and
FCP to this mode. This is the mode selected by most US
productions. ”If this is the case, you should probably edit in a 23.976 sequence and conform your 24 reversed clips to that timebase with Cinema Tools, and all your film edit lists will still be fine.
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I’ve figured it out. The problem was the timecode at which the audio was imported. BWF audio has no info whether it’s 30 and 29,97, so FCP assumes the TC according to your sequence preset at launch. That means you have to change your sequence settings, quit FCP and restart. I read this at another forum, so I went to give it a try.
I used one setting that uses 30 fps (and not 29,97). Quit FCP and reentered. I created a new project to start from scratch and reimported all my audio and 24fps video. Created a 24fps sequence and put the video. This time it lets me sync without trying to change the speed. If I copy the audio from this project to the old one it doesn’t perform the speed change either, so I guess everything is fine.
I also tryed redoing the whole process with sequences presets of 29,97, 24 and 23,98 and none of them worked. Always got the audio out of sync because FCP sped it up. I also tryed the sequence preset think without quitting FCP and that didn’t work either, so I guess they were right when said that what counts is what’s set at launch.
Hope that helps anyone that ever encounters the same problem, since the solution is not very straightforward…
Thanks for all the help,
Alex
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Steven, thank you very much for all your help and effort. I checkd with the guy that captured the sound and he said that he never turnec the “C” on. He also said that if it was on it probrably wouldn’t have synched on the telecine. So far it sounds like I’ve found a solution and I posted it.
Thank you very much for your help again,
Alex
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Here’s an old link from Andreas Kiel that says about the same thing you found:
“BWF Timestamp is readable since FCP 5.1.2 – but this doesn’t mean that the timestamp is interpreted correctly, since it is interpreted based upon the setup FCP had at launch time.”
https://forums.creativecow.net/thread/30/856234
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[Alex Saggese] “Hope that helps anyone that ever encounters the same problem, since the solution is not very straightforward…
“No it is not. I have seen and heard about this problem when you receive and import audio recorded and intended for use in a PAL enivronment and your project is NTSC to start. It is an odd behavior for FCP as it seems to somehow tag the audio with an NTSC frame rate if that’s what your start the program with and after you change the setting, the tag does not get changed and there’s no way to change it unless you restart FCP and try again with the proper setup.
Nice sleuthing, Alex.
Jeremy
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Alex,
Thanks SO much for this explanation. The AT LAUNCH thing… and that AIF doesn’t have TC metadata. I suppose WAV is the same as BWF?
I think that’s why I’ve been more confused than ever about how Final Cut deals with audio after millions of tests. I read somewhere else before that once you’ve imported an audio file, Final Cut flags it and imports it the same way afterwards, but I have not been able to determine a consistent pattern. In fact, I’ll go through the same exact procedure twice using the same audio (quitting FCP, starting a new project, etc.) and get different results with some things. I think I’ll try it all again keeping the launch settings in mind and see if I can get consistent results this time!
This “feature” of Final Cut is absolutely maddening. How much easier it would be to just be able to set HOW you want your audio interpreted! It is so counterintuitive to have to set your sequence preset to how you want your AUDIO to import, as opposed to the rate of how you want your video.
*sigh*
Now, my question is… does this affect Cantar’s faux “C” mode? Because I’m editing a project reverse TKed to 23.98, and importing audio with that sequence setting at launch that was recorded in the C mode, which should give me sync, but it appears I do not. Final Cut is not applying pullup or pulldown (and those are perfectly acceptable terms in audio by the way–in other words, they are used professionally and understood) but the audio behaves as if it were recorded at regular 24fps/48000 instead of 48048 stamped at 48000.
Pulling hair out,
Nayeli
Nayeli
-Nayeli
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[Nayeli Garci-Crespo] “Now, my question is… does this affect Cantar’s faux “C” mode? Because I’m editing a project reverse TKed to 23.98, and importing audio with that sequence setting at launch that was recorded in the C mode, which should give me sync, but it appears I do not. “
make sure to start a new project, choose an easy setup, make a new sequence with that easy setup, then save and quit. Then relaunch FCP.
Jeremy
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