Workaround for 23.96 Frame Rate

I ran into this problem a while back and wasn't able to work it out at the time, but I think I found a solution later on. I never tried it out, but it looked like it would work. Unfortunately I found the solution in another DAW:

(First of all, I hope this thread doesn't get pulled for me saying this)--but in pro tools, there is a pull-up/pull down setting in the bounce dialogue, so you can do your mix within logic, then import it into Tools and do the pull-down there.

Hope that helps. If I understood your question correctly, you are working audio in Logic, but when you take the audio back to your video app, the synch drifts, is that correct?

Working in 23.976 in Logic is a PITA mainly because you can't reference Logic's own timecode counter for things such as hit points and tempo operations. However, working at 24 won't cause drift of your music against picture, even over a 6 minute cue.

The timecode burn added to a picture is (literally) a video overdub. An image of a number is overlaid on each frame of the film or video, and each number is unique. That's then rendered out. Sort of like bouncing two tracks.

While the update to Logic 8 (or 9) is a drastic one, being able to work at 23.976 is one reason why it might be worthwhile to update. Honestly, if I had my druthers I'd still be working in Logic 7.1.1; despite the huge bugs it was the best version they ever made. Making the leap from L7 to L8 was like they moved all the furniture around in your house while you were sleeping. But if you were to do so you'd at least have the ability to work at 23.976.

Regarding sync, give your editor timecode from picture and ignore Logic's t/c counter entirely when working in this situation. Trust me, you won't have any sync problems if you take that approach, even over a feature-length film.

Post back if you want details of why this is the case.

Regards!

Hi Dee,

I just happened to run into a thread on LPH where I posted about this back in 2007. Quoted below, slightly abridged from my original posting.

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You can work on a film at the 23.976 frame rate in Logic (7) to the following extent:

1. You will not be able to get Logic's timecode counter and the movie's timecode burn to match for more than 43 seconds (approximately) from any point where you attempt to get Logic's t/c counter to agree with picture's timecode burn. This assumes that Logic's frame rate is set to 24 fps.

2. When you deliver cues, you will not be able to use Logic's timecode counter to provide accurate information as to where to trim audio files with respect to picture, or for providing the music editor with in/out points for each cue you write. Instead, you will have to trim your cues (and/or pop your files) according to the picture's timecode burn, ignoring Logic's t/c counter entirely.

There is one exception: when trimming audio files, or setting points to pop cues, you need to make adjustments to Logic's SMPTE bits counter to position the SPL to the +leading edge+ of whatever frame you're targeting in the picture. Otherwise your audio can be as much as 1 frame off from where it should be. (Post back if you want details)

3. All of Logic's tempo based functions will work as usual, but you will not be able to go by any timecode numbers that Logic displays with respect to these tempo functions (tempo list, tempo interpreter, SMPTE display of note position, etc.).

Ultimately, Logic's frame rate setting does not influence sync, i.e., having Logic set to the "wrong" frame rate will not affect your sync to picture. This is because Logic doesn't "drive" the playback speed of the QT movie.

I scored my last 23.976 film where some of my song files were set to 24 fps and others at 29.97 nd, and neither one offered me any advantage in terms of working with timecode. I had to do everything referencing the picture's timecode burn. In some respects...it made life absolutely miserable that I couldn't perform certain operations based on Logic's t/c display.

Depending on your method of working to picture, the lack of 23.976 frame rate may or may not get in your way. One thing is for sure... it should not prevent you from composing to picture or have to worry about sync. The sync you see/hear is the sync you get when you deliver cues.

One last word: in general, but particularly with 23.976 footage, I'd strongly suggest working with Contiguous Sync switched off.

Cool!

Just a little postlude. Having contiguous sync on does in fact cause Logic to vary the playback rate of (thinking... it's been a while) the sample rate of the audio embedded in the video. But I remember (much more distinctly) that having it turned on seemed to cause irregularities in the video sync. I just always worked with it off and found that I never had to worry about video playback inconsistencies. BTW, that option has been removed in L8 (and L9) so that probably says something.

Logic 7 vs a more recent version. Yes, it'll be a big change in workflow should you ever decide to go for it. There are many great features (particularly in L9, i.e. flex) and bug fixes (though not as many as you might expect). Beatmapping is severely improved (yay). Notehead display in regions removed (nay!). With L9 you lose the ability to recall your undo history when you re-load a session (boo!!!) but the score editor has many improvements (new!!) But lest I start to get more Dr. Seuss about it any longer...

With Logic 8 you have to do a helluva lot more mousing (or keystroking) to achieve an equivalent workflow as you have with 7. Actually, I take that back. You can't achieve an equivalent workflow; you have to do more work to achieve the same results. This mainly has to do with a change in window focus behavior. With L8 and L9 you have to literally point Logic in the direction of what you want to edit by clicking on various windows. Hey, some people don't mind the change from L7 so maybe it'll work for you. And some people haven't ever known L7 so they don't know what they're missing. Me? I haven't learned to love it yet. Prolly never will.

Finally, you mentioned Logic getting bogged down by the film. Aside from the contiguous sync thing... by chance are you playing back an MP4 or other movie file not encoded with DV?

Open the movie directly in QT and hit CMD-I. That'll tell you what codec it's encoded with.

Prolly not a good idea to take a 23.976 movie and re-encode it as 24. At face value the difference in frame rate may seem slight, but it's definitely going to throw off your sync if any of your cues are longer than 43 seconds in length. And any sync points you communicate to the director about will be off on the tails. So let's say you have a 3 minute cue that starts on (picture) 01:10:00:00 on an edit (an important hit point) and ends on another important hit at 01:13:00:00. Those are time timecodes you're seeing on picture, and you hit them spot on. Now, send that to the editor. When he lays that up in his system, your first hit will line up, but the last one will be off by several frames.

DV is the best encoding to use with Logic. That's not to say that other codecs won't work well, but it seems like macs are happiest playing back DV under Logic.

Don't re-convert, just use the original.

Sorenson 3 should be fine.

Big picture size there, though. Could (possibly) be bogging things down. Are you running this video from a dedicated drive?

Logic's sync settings ("validate MTC" and so on) have no bearing on picture playback. Here's how it works:

Logic "hosts" the movie. Then, in terms of getting the QT movie to play from any particular position...

The movie start time (MST) setting is a starting point for timecode calculations. The difference between that value and the one set for the first tempo event at 1 1 1 1 (see the tempo window) determines an offset into the movie file, i.e., what frame you see when the SPL is parked at 1 1 1 1. So...

If the MST is at 1 hour and the first tempo event at 1 1 1 1 is at 1 hour, when the SPL is positioned at 1 1 1 1 you see the very first frame of the entire movie file (likely the first frame of leader).

Let's say you're working on a cue 1/2-way into the film. With your MST still set at 1 hour, you've set the tempo event at 1 1 1 1 to be 01:30:00:00. The difference is 30 minutes. Thus, when the SPL is positioned at 1 1 1 1 you're seeing the picture 30 minutes into the film.

So all Logic's doing there is providing the QT driver with an offset into the film. When you hit play from 1 1 1 1, Logic sends "play" to QT. From that point on, the QT player freewheels playback of the movie file. There is no actual sync between Logic and QT.

If you started playback from bar 27, Logic calculates that 30 minute offset plus the additional time from 1 1 1 1 to bar 27 and sends that positioning info to QT. And so on.

Message was edited by: iSchwartz

Not to put too fine a point on it, but Logic isn't generating SMPTE code internally that's then driving playback of the movie. There is no connection between Logic and QT, or even the other way around, other than Logic sending "play", "stop", and offset-into-the-movie positioning information to QT as I explained above. That's why the MTC settings and all that have no bearing on sync.

And remember, the timecode shown in the picture is purely a visual thing. It's not connected in any way to some kind of digital timecode reader or driver. It's nothing more than an image of a number overlaid on each frame.