Audio Specifications

Audio AAF/OMF
Audio should be turned over as an intermediary EDL and group of linked audio files. The current workable solution is known as an AAF and/or OMF audio export.

AAF and OMF export works from these common video editing systems:
Premier
Avid
Final Cut X -Requires extra software X2Pro
DaVinci Resolve V15 (there is no current working option to export from this edit system, though some work around options include exporting the project to FCPX then exporting to AAF but this has a limited success rate.
Final Cut Pro version 7 see below

Added Instructions for Final Cut 7
Final Cut 7 OMF export creates one large file with media and EDL info embedded in one file. Please note that the embedded OMF export from Final Cut 7 must be limited to under 2 gigabytes in size. This will require a large project to be split into manageable divisions before export. For example one export will include just audio track 1 and 2 a second export will include audio track 3 and 4 and so on until all tracks are exported.

These tracks will then be grouped together again in one session after import to the sound edit system.

The video does not need to be split into sections if the AAF/OMF is split due to size restrictions. There is no file size restriction on video. Though it is best reduce the size of a video file for internet transfer workflow.
Each split AAF/OMF section should start in the same spot in the time line so that it is in sync with the final complete video and matches the original timecode. Placing a single frame 2 pop on each track is a sensible sync check reference.

Please note that there are other options for exporting from edit systems that are not listed here.

Encapsulated OMF vs Encapsulated AAF

General rules are that there is a 2 gigabyte size limit to encapsulated or embedded OMF files. AAF files can be larger than 2 gigabytes. I have successfully opened a 17gigabyte encapsulated AAF file.

Encapsulated AAF vs Export AAF file with separate Audio Clips Folder

AAF Exports work well as encapsulated for projects under 20 minutes.
(Encapsulated means the export will create on file with meta data and audio files lumped together like a zip file but not compressed)

Larger projects will benefit from the separate audio files option. The result is the export creates a folder with all audio files from the project with one smaller sized AAF file that contains the timeline matching information for the audio files as clips referred to a meta data. A valid working option is to place the meta data AAF file in the folder with the audio files so is al together. Please note the meta data information in the AAF file is unique to each export. The result is the audio file names will only link to one exported meta data AAF file. A second export can not be used to match to audio files from a previous export (At least that is the case for Premier)

The AAF export is really slow - Try OMF

I have had video editors working in Premier complain that the AAF export on a long form project is taking a very long time. In that case use the OMF export option. Warning in that case the encapsulated option is best and you may need to export only 1 or 2 tracks at a time in separate exports due to the 2 gigabyte file limit.

The Preferred AAF/OMF Export Window Settings
  • 16 or 24 bit, whatever matches the current picture edit
  • 48khz sampling rate (Please advise if you are using Pull Down audio rate of 47.952 to perform some sync tests.)
  • Handle length of 240-480 frames
  • Include Crossfade Transitions
  • Include Levels
  • Include Pan

Leaders
The audio tracks in the AAF/OMF should contain the audio pop that matches the head leader. Placing a single frame 2 pop on each track is a sensible sync check reference. The sync pop is a 1khz (1000hz) tone that is 1 frame in duration. Recommended 2 pop level is -30db. Watch your ears if all tracks have full level 2 pop!

Edited Production Audio
The OMF/AAF export should include all usable production microphones. It is hugely beneficial that the audio tracks are organized so that the production mix track and split boom mic and isolated lav mics remain consistent through out a scene. For example: the top track is the mix track and the isolated lav mics per character are below with the boom options on the bottom. Arrangements may vary as long as they are consistent.


As a rule, a good boom track is better sounding than isolated lavs, but every project is different.

Larger projects that are afforded the time to complete a dialog edit
  • Please submit all the raw original production audio with sound reports.
We prefer to receive audio as audio files, if there was not a secondary sound system, as in audio direct to camera. We prefer not to receive any of the original video from production.

Edited Music and Effects

The basic rule is to group like sounds together on their own tracks. If possible organize the video edit audio tracks so that there are separate audio tracks keeping dialog, music and effects split in their own groups of tracks. Do the best you can here but if its not perfect its not a problem if few things overlap.

Some Known Premier Export Bugs!

When exporting media as AAF the file names of clips are lost. The result is song titles and other valuable clip information is changed to usually one random name form the video editors project. This is an issue when it is time to export the music cue list for legal.

When exporting OMF there is a plus frame or delay sync drift after some not all cross fades. This clip movement is limited to the clip after the cross fade only and does not move the entire track out of sync. The amount if sync offset is oddly half the frame length of the crossfade. (A work around is do not include crossfades on OMF export or delete cross fade in timeline before export)