About Offline and Online Editing

The offline/online workflow allows you to use temporary, reduced-quality copies of your footage to edit with, and then finish your project with full-quality media. Reduced-quality media files require less hard disk space and less computing power to process transitions and effects. This means you can edit on an inexpensive computer or a portable computer and then finish at full quality on another system. Once the creative cutting is complete, the online editing phase (also referred to as the finishing phase) focuses on image quality, color correction, proper broadcast video levels, and so on.

The two phases—offline and online editing—are connected via an Edit Decision List (EDL), or other project interchange file, which is used to transfer all of your editing choices from the finished reduced-quality session to the final high-quality session.

Offline Editing

Editing with reduced-quality copies of your media files allows you to fit more media on your scratch disks and improve playback and real-time effects performance (especially when using slower hard disks, such as in portable computers). This phase can last from a few days to several years, depending on the scope of the project, the amount of footage, and so on.

Edit Decision List or Other Project Interchange File

When the edit is complete, you can export all of your edit decisions for use on another editing system. Older editing systems use a relatively simple text format called an EDL, while newer interchange formats, such as OMF, AAF, and the Final Cut Pro XML Interchange Format, describe many more details of your original sequence.

Online Editing

Online editing, now better known as finishing, starts with an offline project file or a project interchange file, which describes the media you need to reingest at full quality. Online editing actually has very little to do with editing in the traditional sense. Timing, storytelling, and fine-tuning your edits should be complete in the offline editing phase. Online editing focuses on image quality, color correction, maintaining broadcast video specifications, detailed effects work, titles, audio levels, and so on. Compared to the offline editing phase, an online edit session goes very quickly (anywhere from a day to a week), and generally requires more expensive equipment.

Important: It is critical that you maintain accurate timecode, reel names, and file metadata for keeping track of where footage is located in both tape-based and file-based media. Make sure you log clips and label tapes and other media carefully so that you can reingest footage at any quality at a later time.

How Audio Is Handled in the Offline/Online Editing Process

The offline/online workflow tends to focus on video, but how is audio handled? Audio has much lower data requirements than video, so audio is almost always ingested at its native sampling rate and bit depth, even for offline editing. This means the audio is ready for a final audio mix without reingesting.

During the offline editing phase, audio clips are synchronized with video and placed in the sequence, and basic level adjustments are made. Once editing is finished and the picture is locked, audio is mixed in the audio mixing and sweetening phase. You can mix your audio in Final Cut Pro, or transfer your audio files and audio edit decisions to an audio post-production application.

The audio mixing phase is analogous to the video online edit session: the goal is to produce a continuous, natural-sounding mix by setting proper levels, setting panning (locating sounds in different speakers, either for stereo or surround sound), and using any necessary audio filters. When the audio mix is complete, you bring it to the online edit session for an audio layback into the finished sequence (or directly onto the finished master tape). For more information about audio mixing in Final Cut Pro, see Audio Fundamentals.

To transfer your sequence audio to an audio post-production application, you need to export two things.

  • Audio clip information: In and Out points, location in sequence, and audio levels. Some people may simply call this an audio Edit Decision List. The audio media itself is not included.
  • Audio media files: These are the actual media files referred to by clips in your sequence.

You can export your audio edit decisions to project interchange formats such as OMF, AAF, or the Final Cut Pro XML Interchange Format. Some audio applications can also recognize EDLs.

Audio media files can be exported as AIFF, WAVE, Sound Designer II (SD2), or any other QuickTime-supported audio file format.

Important: Using the OMF and AAF formats, you can export both sequence information and media files in a single file. Although this file can be quite large, it can be convenient to have all the audio data you need in one self-contained file. Both an EDL and a file in Final Cut Pro XML Interchange Format contain only sequence information, not audio media. This means that in addition to the project interchange file, you need to transfer your audio media to the facility doing your mix.

The interchange format you choose depends on which formats your audio application recognizes. For more information, see Exporting Audio for Mixing in Other Applications.