Apple DVD Studio Pro 4 - Manual (Page 89)

There are two common PCM audio formats:
• AIFF audio (Audio Interchange File Format-uncompressed PCM audio; the most common
Macintosh audio format)
• WAVE audio (Windows uncompressed PCM audio; the most common Windows audio
format, also referred to as WAV)
The DVD Studio Pro integrated MPEG encoder creates AIFF format files. In most cases,
DVD Studio Pro converts WAVE files into AIFF files.
Compressed Audio Formats
The DVD medium uses data-compressed (as opposed to sonically compressed) audio for
two purposes:
• To deliver discrete surround audio (5.1)
• To conserve bandwidth and disc space, allowing more room for video. This is especially
applicable in long-form material such as feature films, notably when the smaller DVD-5
medium is the target.
Data-compressed audio for DVD comes in a few forms, described next.
MPEG-1 Layer 2 Audio
For DVD products in PAL, MPEG-1 Layer 2 audio is compatible with all players. For NTSC
markets (North America, Japan), most (but not all) DVD players support playback of
MPEG-1 Layer 2 audio. If you create NTSC titles using MPEG audio, be aware that there
may be problems in playback on some players.
If you want to ensure that your data-compressed audio is compatible with all players for
NTSC, using the AC-3 format is recommended. See the next section for information on
encoding and authoring with AC-3 format audio.
Dolby Digital AC-3 Audio
There are two good reasons to use AC-3 format audio in your DVD production:
• To take advantage of 5.1 surround audio (five main speakers and a subwoofer—six
channels of audio total), which is supported by AC-3 but not by MPEG-1 Layer 2
• To produce stereo data-compressed audio that is fully compatible with every DVD
player in the NTSC markets of North America and Japan. You may run into some
compatibility issues with older DVD players in PAL countries.
You can use the AC-3 encoder in Compressor to encode everything from stereo to 5.1
surround audio. See
Previewing AC-3 and DTS Audio for information on listening to
surround audio.
89 Chapter 5 Preparing Audio Assets