4.5

51Compressor User Guide
• Sample rate: Use this pop-up menu to set the number of times per second that music
waveforms (samples) are captured digitally. The higher the sample rate, the higher the
audio quality and the larger the file size.
• Data rate: Use the slider to set the number of kilobits per second (kbps) required to
deliver your audio file. Using a higher rate will produce a higher-quality audio file.
• Use variable bit rate encoding: Select the checkbox to vary the number of bits used to
store the music depending on the complexity of the music. Variable bit rate encoding
can reduce the size of the output file.
• Joint stereo: Select the checkbox to have one channel carry the information that’s
identical on both channels, and another channel carry unique information. At bit rates of
160 kbps and below, this setting can improve the sound quality of your converted audio.
• Smart encoding adjustments: Select the checkbox to have Compressor analyze
the source file and the setting’s encoding properties to maximize the quality of the
output file.
• Filter frequencies below 10 Hz: Select the checkbox to have Compressor remove
inaudible frequencies from the source file and output a smaller and more efficient file
without perceptible loss of quality.
Audio effects
For a list of available audio effects in Compressor, and instructions on how to add an audio
effect to a setting, see Add and remove effects in Compressor.
MPEG-2 setting in Compressor
The built-in MPEG Files settings in Compressor use the MPEG-2 transcoding format. (The
MPEG-2 for DVD setting in the Create DVD destination also uses this format.) Use this
format to encode MPEG-2 stream files for DVD and Blu-ray authoring.
Note: You can also create custom settings that use the MPEG-2 transcoding format.
However, the built-in MPEG-2 settings (in the Settings pane) analyze your source media
and assign optimal properties to ensure the best possible transcoding results.
The built-in MPEG-2 for DVD setting encodes only a video file. To encode the
accompanying audio, use the Dolby Digital audio setting. The easiest way to do this is to
apply the Create DVD destination to your source file, which adds both the MPEG-2 for DVD
setting and the Dolby Digital setting to your job. For more information, see Dolby Digital
settings in Compressor.
The properties of built-in and custom settings that use this transcoding format are located
in the General, Video, and Audio inspectors (described below).
Setting summary
Displays the setting name and transcoding format used by Compressor, as well as an
estimated output file size. When you add a setting to a job or change the setting’s
properties, this summary is automatically updated.