About Multitrack and Audio File Projects

Soundtrack Pro has two native project file formats to support state-of-the-art multitrack audio editing and powerful nondestructive audio waveform editing:

Multitrack Projects

Multitrack projects contain multiple audio tracks in the Timeline. As in a Final Cut Pro project, importing a media file creates a clip in Soundtrack Pro that then refers to the original media file. You can arrange audio clips within tracks and synchronize them to a single video clip in the video track.

You can mix a multitrack project using track controls for volume, pan, mute, solo, effects, and effect parameters. These controls are available both in the Timeline and in channel strips in the Mixer. You can create additional audio busses for effect sends. You can group audio track outputs together with submixes. Tracks, busses, and submixes can be exported to individual audio files, or a mixdown of all the tracks can be exported to a stereo or multichannel audio file. These exported files can then be imported into Final Cut Pro.

Audio File Projects

Soundtrack Pro allows you to edit individual audio files (sometimes known as waveform editing) using Soundtrack Pro audio file projects. However, unlike most waveform editing applications, Soundtrack Pro allows you to edit your audio files nondestructively by keeping track of the actions you have performed on your audio file. For more information about Soundtrack Pro audio file projects, see Working in the File Editor.

You can remove, disable, or reorder past actions at any time or save actions as AppleScript documents that you can use to batch process other audio files. Actions you can perform include trimming audio, copying and pasting parts of the waveform, normalizing or amplifying levels, applying effects, and applying noise, pop, and click reduction.

Soundtrack Pro audio file projects are stored in Mac OS X packages (or bundles). A package appears to be a single file in the Finder but actually contains a collection of files such as the original audio file, temporary render files, and the list of actions applied to your audio file.

Important: So that you benefit from nondestructive editing, the default option for saving edited audio files is as a Soundtrack Pro audio file project. Soundtrack Pro usually does this automatically any time you apply any command or effect from the Process menu to a clip in the Timeline. For more information on when Soundtrack Pro automatically creates audio file projects, see How Source Audio File Editing Works in a Multitrack Project.

Supported Audio File Formats

You can open and add audio files in the following formats:

  • AIFF

  • WAVE

  • Broadcast WAVE

  • Sound Designer II

  • NeXT

  • QuickTime (.mov) audio files

  • CAF (Apple Core Audio Format)

  • Soundtrack Pro audio file project

Compressed formats such as MP3 and AAC (except protected AAC) files are also supported, although these must be internally decompressed to a linear PCM format.

Soundtrack Pro supports audio files with any sample rate between 8 kHz and 192 kHz and any of the following bit depths: 8, 16, 24, 32, and 32-bit floating point. Up to 24 audio channels are supported in a single file.

When you set a sample rate and play a file, Soundtrack Pro plays at the nearest sample rate your hardware can support.

Note: Files with lower bit depths or sample rates do not have the same playback quality as formats with higher bit depths or sample rates.

You can also open and add the following types of multichannel files:

  • AIFF

  • WAVE

  • Broadcast WAVE

  • QuickTime

  • Single Folder Multi-mono AIFF and WAV

Supported Video File Formats

Soundtrack Pro supports the following file formats:

  • Standard QuickTime-compatible file formats. You can import a QuickTime movie (.mov) file into a Soundtrack Pro project, and you can import an MPEG-2 (.m2v) file if you have installed the QuickTime MPEG-2 Playback Component.

  • Video files using NTSC, PAL, HD, and other formats supported by QuickTime

For more information about importing video files, see Working with Video in Soundtrack Pro.

About Looping and Non-Looping Files

Soundtrack Pro supports two types of audio files: looping and non-looping files. Most audio files are non-looping files unless they contain tags for tempo, key, and other information.

Many of the Apple Loops that come with Soundtrack Pro, as well as other tagged audio files, can be looping files. Looping files may contain music, rhythmic sounds, or other repeating patterns. You can resize a looping file to fill any amount of time. Looping files adjust to the project tempo and key, letting you use loops recorded in different keys and at different tempos in the same project.

Non-looping files do not adjust to the project tempo and key. You can shorten or lengthen a non-looping file, but lengthening it beyond the size of the original file adds only silence to the lengthened part. You can search for non-looping files in the Search tab using the Search text field.

Both looping and non-looping files can contain tags with information about the file, including mood, genre, and musical instrument. Soundtrack Pro recognizes tags in audio files intended for use with loop-based music applications. You can open an audio file in Apple Loops Utility and add tags, and can convert a looping file to a non-looping file, or convert a non-looping file to a looping file. For information about tagging audio files using Apple Loops Utility, see the Apple Loops Utility User Manual.