Why OMF?

A popular, cost-saving method for submitting audio materials to RocketWerks is to create an OMF file. This procedure allows us to open your project in Pro Tools and start work immediately. Without an OMF output, we typically spend a day or more autoconforming location sound materials from 1/4" Nagra or DAT tapes. An OMF can save time and money as we begin work on your project.

In short, the OMF project file contains all of your file information, generally with head and tail handles (we prefer 8 seconds or more), as well as all of the timecode data. When received from an Avid, all of your volume automation is maintained. Final Cut Pro currently does not translate volume automation information through an OMF.

Although we do not always recommend using OMF transfers for feature films (unless the audio is digitally transfered directly into the workstation), it may help you complete your short film, trailer or advertisement under budget. However, to use this method you need to plan ahead. The steps that follow will ensure a painless transfer and great-sounding audio materials.

First, the only editing systems which can create an OMF file are an Avid or Apple's Final Cut Pro (at least version 2.0). Earlier versions of Final Cut Pro, Adobe Premiere, EditDV, and most other non-linear video editing systems cannot create an OMF.

Second, in using an OMF, the dialog we edit and mix will be the same audio that you load into your Avid. This means that you need to take great care in recording your audio into the Avid. Preferably, the location recordings will be digitally transferred from a timecode DAT. The next best source is a high-quality transfer of the location 1/4" Nagra tapes. Short of that, audio can be loaded from your telecine videotapes, but this audio will already be second-generation. If you shot your film in HD or DV and used the camera tapes as your master or back-up audio format, your audio can be loaded digitally directly into the workstation and is absolutely ideal for creating an OMF.

If it must be an analog transfer, at the very least, use high-quality balanced connections and strong recording levels when loading audio into your system. Also, make sure that the audio is not distorted or noisy when you load it. In general, dialog should be digitized at -20dB or more on a digital full scale meter (where "0" is the highest peak on the meter) and should NEVER peak. Choose 48kHz as your sampling rate.

Creating an OMF File from an Avid

When you have a final cut, and you're ready to output an OMF file, follow these instructions.

Save the OMF file to a drive for transferring to Pro Tools

This method creates one large file for each reel. If you have several tracks of music and temporary effects, this file could easily be over 500MB for a 15 minute reel.

There is another method of outputting an OMF file. If you do not check the "Use Media" box, the OMF output creates a small file which references the audio files on your drives. However, we have had problems in the past opening OMF projects which have been prepared this way. We DO NOT RECOMMEND this method. Please check the "Use Media" box, even though the large file size can be seemingly difficult to deal with. If you must prepare this way, please be absolutely certain that the proper "OMFi Media Files" folder is copied over and delivered with the master OMF project file. Sorting the folder by "Date created" can help you pinpoint the necessary files that should accompany the master OMF project file.

If you have any questions when creating an OMF file, refer to the Avid Collaboration Guide (requires Adobe Acrobat Reader) or contact RocketWerks.

Creating an OMF file from Apple's Final Cut Pro

Final Cut Pro makes it easy for us to begin working on your project, and if you transfered the audio digitally into the workstation, we will be using the original first-generation recordings you made on-set.

When you have finished editing ("locked picture"), this is how you export an OMF file:

1. Under the File menu, select Export > Audio to OMF...




2. In the window that pops up, select the sampling rate of your project. This should have been decided during digitizing, and should be either 44.1K or 48K. Also, select 00:00:08:00 as your handle length. Make sure that "Include Crossfade Transitions" is checked.




3. Save your OMF file on a drive. This file is usually around 500MB for a 20 minute reel.

Delivering the OMF file: Media or FTP

The final step is to transport this file to RocketWerks; we can take a DVD, CD, or firewire drive. You can also upload to our ftp site; please contact RocketWerks regarding this option.

As we mentioned above, we prefer not to use OMF files for feature films that are unable to capture a first generation digital transfer of audio. This ensures that your film's dialog will sound as good as it possibly can. However, an OMF output may suit your project. Please contact RocketWerks for more information about OMF transfers, and to find out if it's the right choice for your next project.