Adobe AUDITION 1.5 - Manual (Page 247)

239 ADOBE AUDITION 1.5
User Guide
Windows Media Audio (.wma)
The WMA format utilizes a perceptual compression scheme and lets you select from three
different encoding options:
• Constant Bit Rate Encoding varies the quality level as needed to ensure that the bit rate
stays the same. This method makes a consistently sized file, although the quality may
not be as high as with Variable Bit Rate encoding.
• Variable Bit Rate Encoding maintains the audio quality by varying the bit rate
depending on the complexity of the audio passage being encoded. This method can
maintain higher quality audio in the file, although the file size is not as predictable as
with Constant Bit Rate encoding.
• Mathematically Lossless Encoding compresses to a smaller file size than WAV, but
results in no fidelity loss.
After you select an encoding option, you can set the desired quality. Just as with stereo
WMA files, the higher quality setting you select, the larger the file size, and vice versa.
Windows PCM (.wav)
The Microsoft Windows PCM format supports both mono and stereo files at a variety
of resolutions and sample rates. It follows the RIFF (Resource Information File Format)
specification and allows for extra user-information to be embedded and saved with the
file. The WAV format reproduces digital audio by using PCM (Pulse Code Modulation)—
PCM doesn’t require compression and is considered a lossless format.
Options The following options are available for 32-bit files; no options are available for
8- or 16-bit files:
• 32-bit Normalized Float (type 3) – Default is the internal format for Adobe Audition
and the standard floating point format for type 3 .wav files. Values are normalized to the
range of +/–1.0, and although values beyond this range are saved, clipping may occur
in some programs that read them back in. (Adobe Audition won’t clip audio but will
instead read the same value back if it’s beyond this range.)
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