24 Mar Prepping and Exporting for Post Audio in Final Cut Pro
Beginning the audio edit of the post production sound process requires receiving the correct files and media from the editorial facility. I’ve always had my standard “list of deliverables”, but over the past few years I’ve found that quite often the export of these files from Final Cut is not done properly. Thus, I’ve created a document (as well as explanations) outlining what a sound editor might need, why, and how to do it.
We need 3 main things in Post Audio: The media, the file which points to the media, and a video copy of the project to use as reference. The project file and media are pretty self explanatory, however, the video can complicate things. Audio needs the video file so they can:
- Match the old / original audio and new audio against the picture.
- Check sync of all dialogue, music, and effects.
- Place foley and sound effects at specific points in time.
As I’m sure you can understand, all of these go on the assumption there is “picture lock”. A more appropriate would be “picture timing lock”, as every edit and decision a sound editor and mixer makes is dependent on the timing of what is on screen. If the timing of the picture is changed during post audio, the sound will fall out of sync instantly – like dominoes. That is why it is paramount to have complete picture lock before starting audio. Unfortunately, due to timing constraints on some pieces, the audio edit has to happen while picture is still being edited. This can be the most grueling part of being an audio editor. Products like Virtual Katy help bridge the gap by comparing old edits to new edits and moving audio appropriately. However, there is no one click fix, and I cannot stress enough: if at ALL possible, only work with a cut with picture timing lock.
Next, editorial has to provide post audio with a video with a visible timecode marker on the video. This is referred to as a “Time Code Window Burn“.
Now that we have that clarified, let’s move into the specific requirements.
I. Quicktime movie with Academy Leader, 2-pop, and tail pop and embedded audio guide track. (see below for EXPORT settings)
Academy Leader is that familiar 8, 7, 6, 5, 4, 3, 2 countdown you see before some older films. Each number is on the screen for 1 second, except the “2”, which is on for 1 frame (this is where you hear a beep – also 1 frame in length). This is what’s known as a 2-pop. The Academy Leader is a carryover from mechanical film projector days. The machines had to have time to “slew” – that is, ramp up to speed so the film projector and audio system could get up to speed and be in sync. The 2 Pop was an audible indicator that things were in sync, because it lasted just as long as the visible “2” – and at the same moment. A tail pop is analogous to the 2-pop – only at the end of the film. This is used to ensure that sync is retained through the entire piece. If the 2 Pop is in sync, but the tail pop is not – then there is a sync issue somewhere within the piece. I use this as a simple check. I also like to have the picture editors audio “mix” as a reference / guide – not only for yet another way to check sync, but because many directors & producers fall in love with audio work the picture editors do – and may want to use those in the final mix. (Ed. Note: See comments below for a correction to this explanation when dealing with film and feet)
II. OMF export that includes all audio data and NO video (see OMF export details below)
OMF (Open Media Format) is a “container” of media, along with instructions for your audio editing system as to where to place these media files in the timeline. If your audio editor is using Pro Tools – you’re in luck – Pro Tools can understand OMFs, provided they have that option purchased & enabled. Pro Tools can read OMFs with audio – but not video. Thus, the video must be generated separately.
Details for Final Cut Pro Media Export
- If for TV, divide your program into reels that span commercial break to commercial break.
- If for film, divide your program into reels, corresponding to the same length as your picture reels.
(these above two allow for smaller segments of media to be transferred from the editorial house to post audio, and is easier on the editing systems to generate and work with, plus the opportunity to not screw up the entire piece, if just one reel’s timing has to be changed)
- Quicktime .mov**
- Timecode window burn (SMPTE timecode – HH:MM:SS:FF)
- Insert Academy Leader, 2-pop, and tail pop into your sequence
- If academy leader is not used, then a black slug with a one-frame visual pop 2 seconds before FFOA (first frame of action) and 2 seconds after the LFOA (last frame of action) must be added. Additionally, an audio pop (1kHz one-frame beep) must be added to match sync with the visual pop.
TIME CODE BURN:
Make a new sequence in FCP, maintaining same sequence settings as your master project. Name it same as the original locked sequence plus “_TC”. Nest your entire master project sequence into the new sequence (you can do this by dragging your master project sequence onto the time line of the new sequence). If you don’t nest the sequence, the timecode print will not print continuous timecode from HeadStart to tail sync. Be sure the PICTURE START mark is the very first frame of the timeline.
In the Browser, (important–NOT from the Effects menu) click the Effects tab. Open the Video Filters folder. Then open the Video folder. Click the Timecode Reader effect, and drag it down onto the new _TC sequence. This puts a Time Code window burn on the picture. It is imperitive that when you do this, you place the nested clip in the new _TC sequence at the exact same Timecode it resided at in the original sequence. Why? Because if you don’t, the Timecode reader effect will burn the wrong code into the exported movie, and will ruin any kind of obvious sync point. The OMF you will export for me will not match the video Time Code window burn, and there will be many sync issues.
Next, in the CENTER box click the circle with the crosshairs. The crosshairs will appear in the Canvas. If you click and drag the crosshairs in the canvas, that will adjust the placement of the timecode window. When you have placed the crosshairs where you want the window, release the mouse. Place timecode window to obscure least important pix area, usually bottom-center, within title and action safe.
You can export a QuickTime movie from either the Browser or from the Timeline. Make sure you have an IN and OUT marked in your sequence so the QT movie will be limited by the marks. To export a QT, make sure the sequence with the window burn (see instructions above) is selected in whichever window you’ve clicked in (Browser or Timeline). Then go to File>Export>Using Quicktime Conversion. When the dialog box comes up, name the sequence so you recognize it as your sequence with time code burn (i.e. “your project name_TC.”) Direct it to the folder on your drive where you want to save it. Under Options (where it may say “Current Settings”) navigate to the codec of choice. Click settings and make sure both AUDIO and VIDEO are checked, and that FRAME RATE is set to CURRENT.
Once the QT movie is exported, go back into FCP to export an OMF. Select the MASTER sequence you made earlier (not the _TC), prior to the timecode window sequence. File>Export>Audio to OMF. Make sure your IN and OUT points are the same as your QUICKTIME export, listed above. Change the default Handle Length to AT LEAST 5 seconds (00:00:5:00 – but more is better!). Include Crossfade Transitions should be checked. Click OK and navigate for a place to save the OMF – in the same folder as the Quicktime export. Name it “your project name_OMF” and click Save. This allows the audio editor to get your audio with the same timecode (in the metadata) as the picture you just exported.
- Nested sequences are NOT allowed to be used in your OMF export for audio. If your project contains nested sequences (i.e. your timecode sequence) your OMF will export, but will not be completely usable – your audio files within the nested sequence will be mixed together, and therefore practically unusable in post. Therefore, you MUST un-nest all nested sequences, and place them in your master project before performing the OMF Export.
- OMF files have a 2GB limit. This is due to OMF being created back when 2GB was a huge size! Because this may cause a limitation in long form and audio heavy FCP projects, you may need to export several OMFs. A common practice is an OMF with tracks 1 & 2, an OMF with tracks 3 & 4, etc. Project length and audio density will dictate how many tracks you can export in 1 OMF – and still be under 2GB. It’s good practice to name the OMF with the track names, and what kind of audio is on them: dialogue, music, effects, etc.
**This can be any time of MOV file. The type of file will be dictated by what the sound editor’s computer(s) can playback and use. Often, this will be a DV file (for SD) or DVCProHD (for HD). If the audio facility will be projecting the image, they may require a higher quality MOV file. If a second computer is used for video playback – like Digidesign’s Video Satellite, an even high res file may be requested. Always check with the audio editor for their desired MOV file format.
*My thanks to users of the DUC (http://duc.digidesign.com) for their input on this document!