Apple Logic Express 8 - Manual (Page 266)

266 Chapter 11 Adding Pre-Recorded Media
Logic Express can also import Standard MIDI files (type 0 and 1), GarageBand, OMF
Interchange, AAF, OpenTL, and XML files. These file types are usually used to exchange
projects, however, and are therefore outside the scope of this chapter. Full details on
importing these file types can be found in Chapter 29, “
Project and File Interchange ,”
on page 649.
About Pre-Recorded Media Types Supported by Logic Express
The following section describes all media file types supported by Logic Express.
WAVE and AIFF Files
Wave (WAV) and Audio Interchange File Format (AIFF) audio files are very similar. They
can be stored at different bit depths (16 and 24 bit are supported by Logic Express), in
mono or stereo, and at sample rates up to 192 kHz.
Logic Express also supports Broadcast Wave files, which can contain time stamp
information. Files that provide time stamp information can be recognized by a clock
symbol, shown alongside the audio region name in the Audio Bin window.
The file extension of broadcast wave files is .wav, allowing them to be read by any
application that supports the standard wave file format. In such programs, the
additional Broadcast Wave file information is ignored.
Core Audio Format Files
Core Audio Format (CAF) files are containers that support integer and float PCM
formats, A-law, u-law, and a number of others including AAC and the Apple
Lossless Audio Codec (ALAC). Unrestricted file sizes are possible, at high sample rates
and bit depths.
Sound Designer
Sound Designer I and II (SDII) audio files are similar in structure to AIFF files, and can
contain time stamped region information. Use of Sound Designer format files can make
transfers between Logic Express and Digidesign Pro Tools software more convenient.
MP3, Apple Lossless, and AAC
MP3 and AAC files contain compressed audio information. They are usually far smaller
than equivalent WAV, AIFF, or SDII files. This reduction in file size is due to different
encoding techniques that “throw away” some of the audio information. As a result, MP3
and AAC files do not sound as good as their WAV, AIFF, or SDII audio counterparts,
dependent on the source audio material.
Apple Lossless files also contain compressed audio information. As the name suggests,
the compression used (ALAC) does not discard audio information in the same fashion
as MP3 files. The sound of the compressed audio file is identical to the original
recording.