FCP "bug" to watch out for...

[Sonsey]

This is one that just came up and got me... I know Nathan had some issues with this, as did gsteiner (who's posts on CreativeCow and Apple helped me lick this one...).

If you are working on a project cut in FCP at TRUE 24fps (i.e Animation, or for finishing on Film via Cinema Tools) and you have exported you mix as a .WAV or .aif at that framerate... FCP puts a timecode value on audio it has imported. This value is the fps in the default capture settings -regardless of the fps of the Sequence. On most systems this will be either 29.97 or 23.976. However when you add this to a 24fps sequence FCP decides "Oh this audio has been pulled down, therefore I must pull it up to match with the 24fps timeline" - even if the audio is synced to a 24fps timeline originally. Yes, this includes BWAV files output from PT. The result is that the audio, which matches perfectly your QT movie in PT, and even in QTPro will play out of sync in FCP. Yes you read that right... FCP WILL pull up your audio without asking! So how do we work around this?

1. Have your editor make sure his default capture setting is the same framerate as his Sequence (good luck with this one...)

or

2. In QTPro, export your .aif as a .mov with the correct frame rate.

or

3. Use the Sebsky tools bwf2qt function to export an FCP movie with the correct framerate.

Gotta love that technology! Just thought I'd share this for those who may have had these weird sync issues in the past. You are NOT going crazy...

[Sonsey]

As an addendum, this ONLY happens with 24fps material so it may not directly be related to framerate, but a "pulldown" tag (for lack of a better word). With 25fps material the audio remains in sync, even if the capture preset is 29.97. This MAY be related to the Cinema tools functions which allow you to resync telecine'd material back to true 24fps. The only reason I was able to track this down was because I had laid the audio back into FCP to make a change in the video (20s were cut and the bounce to QT function is always a bit buggy).

[Starcrash]

Are you sure this occurs with AIFF files, too? I thought that the cause of this problem was embedded metadata in BWF files. Maybe this is a separate issue? This is why I've tended to use AIFF only when working on FCP shows.

[Sonsey]

Hey Pascal,

Absolutely... that's the reason I always used .aif, and sure enough, this came up a bit me late last night (the last time you want to be dealing with this...). You can see it yourself. Create a 24fps timeline in FCP. Put bars and tone at a regular interval. Export your movie. Import the movie and audio into PT on a 24fps timeline. Now export the audio using .aif. Put it back in FCP and look for yourself... the audio will now be shorter. It does happen ONLY on 24fps timelines, and I'm using FCP6 so it might be new to that..

[KK Proffitt]

Thanks for the info. FCP has a warning about sequences not matching capture settings, but I think you can turn it off. I guess I'm lucky that I always ASSume AIFF when dealing with Apple apps. I've seen some killer bugs with WAVs earlier.

I've done 24p with advanced pulldown and it's worked well so far. I don't have the very latest rev of FCP6 because I read that they broke P2 capture.

[Sonsey]

Hey KK...

24p with advanced pulldown won't cause a problem, because it's actually running at 23.976. It's ONLY on true 24fps timelines. Of course the most standard reason for doing that is when you're working on a Film Finish using the Cinema Tools Reverse Telecine Process, so it's just Apple assuming that anything coming in will have to matched to the video, which I'm sure is helpful for folks who aren't familiar with the process but a royal PITA when workflow has already been established, or when working in traditional animation (my case).

[KK Proffitt]

Hey KK...

24p with advanced pulldown won't cause a problem, because it's actually running at 23.976. It's ONLY on true 24fps timelines. Of course the most standard reason for doing that is when you're working on a Film Finish using the Cinema Tools Reverse Telecine Process, so it's just Apple assuming that anything coming in will have to matched to the video, which I'm sure is helpful for folks who aren't familiar with the process but a royal PITA when workflow has already been established, or when working in traditional animation (my case).

Ick, ick, ick. Yet another thing to remember. Good to know.

[Starcrash]

Thanks, you guys. This is good stuff to know. It often seems like there's often a bit of voodoo when it comes to FCP-->PT-->FCP shows.

Since we're on the subject, does anyone care to briefly lay out how to avoid the most common bugaboos for this type of workflow? It's been trial and error for me and I'll admit I don't have a totally clear handle on it. Can anyone pinpoint what types of files, framerates, sample rates, etc tend to cause difficulty in FCP? This will be a bookmarker for me.

Sorry if this is a highjack, but I think it could be handy. Any FCP gurus want to chime in?

[Sonsey]

Okay, so this is becoming a MUCH more complicated bug that I first thought. It appears that FCP stamps the incoming audio as NTSC(.01% pulldown) or PAL(no pulldown), depending on what capture preset is being used as the default. SO...if for example in Peter Groom's case, the editor NORMALLY works with PAL and his DEFAULT capture setting is PAL, and then cuts an NTSC 29.97 sequence (even if he changed his capture setting on import), when the editor RE-IMPORTS the audio from PT, FCP stamps it as PAL... then when you add that to the 29.97fps sequence, it assumes it has to pull it down to match...and your audio comes out long. Conversely if the EDITOR starts NTSC as a default and then cuts a PAL sequence, the audio is marked on import as NTSC, FCP assumes it has to be pulled up to match and it comes out short. Just to make things interesting, it appears FCP actually WRITES this information to the audiofile, which means once it's been imported incorrectly once, it will ALWAYS bear that stamp, even if the FCP defaults are changed. Of course TRUE 24fps isn't a valid NTSC rate, so the same pullup will be applied in that sequence as well, which is the problem that got me started investigating all this...

So, to recap IF you are dealing with a framerate that is NOT normal for your country/continent, the BEST option is to either export a QT movie (via, PT, QTPro or the Sebsky Tools) that has the correct frame rate for import into FCP.

WHEW! A'int technology grand... kinda makes me miss the days of aligning DBX noise reduction units... no wait, it doesn't

[subwoof]

kinda makes me miss the days of aligning DBX noise reduction units... no wait, it doesn't

...Hang on....you mean there really WAS a way align DBX noise reduction units? I never found a way to do that, only SR...Maybe I should relive the 80's again and do it right...



Mike