User Manual

Chapter 2: Pro Tools Concepts 25
Metadata
Metadata is used to describe the following:
• Information embedded in a media file. This
may include scene, take, sample rate, bit
depth, region names, the name of the video-
tape from which the media file was captured,
and even time code values.
• Information embedded in Pro Tools sessions
or other sequences, including what files are
used, where they appear in a timeline, and au-
tomation.
• For AAF or OMF sequences, metadata also in-
cludes information embedded in unrendered
AudioSuite™ effects (such as real-time EQ) on
Avid workstations. Pro Tools skips unrendered
effects on import. Rendered effects are media
files that can be imported into Pro Tools.
• For AAF or OMF sequences, information
about automation (clip-based gain or key-
frame gain).
AAF, OMF, and MXF Basics
AAF and OMF files are mechanisms for storing
and retrieving media files and metadata so that
projects can be freely exchanged between differ-
ent applications and platforms. MXF is a media
file format that can be used with AAF (but not
OMF) files.
Media data and metadata enable an application
that receives AAF and OMF sequence files (such
as Pro Tools) to automatically and quickly reas-
semble the composition. A simple metaphor for
this approach is that media data files are the
pieces of a puzzle and metadata is the set of in-
structions for assembling the puzzle.
In the simplest case, only an AAF or OMF se-
quence is exchanged. If this sequence points to
existing media files, the size of the sequence file
is relatively small and the export/import process
is relatively fast.
AAF and OMF sequences can also have media
data embedded in them. This creates a single,
larger file that is slower to export and import,
but which may be easier to manage than thou-
sands of files stored on different volumes.
AAF
AAF is a sequence file format. AAF sequences are
the best way to exchange projects and maintain
valuable metadata. An AAF sequence can refer to
OMF or MXF media files, or have OMF and MXF
media files embedded within them. There is no
such thing as an AAF audio or video media file.
Pro Tools will import, play back, and export an
AAF sequence that either links to media files or
has audio embedded within it.
When you import an AAF sequence with em-
bedded audio into Pro Tools, the audio will be
extracted into mono tracks using the current
session’s audio file format.