User Guide

Sound Forge XP does not come with any ACM Filters; you must obtain them
from other sources. However, since the ACM Filter architecture is fully
documented by Microsoft, it is possible that many types of filters will become
available on BBSs and other places for use with Sound Forge XP. If any ACM
Filters are installed in your computer, you will see the ACM Filter option under
the Tools menu.
Sound Forge XP allows you to use any ACM Filter installed and enabled on your
computer to process sound files. Select the ACM Filter option under the Tools
menu to choose the filter and its attributes that you wish to apply to your
sound data.The ACM Filter tool works exactly like all other Sound Forge XP DSP
functions, including the option to save presets and set custom selections.
TRANSPARENT PLAYBACK AND RECORDING OF
NON-HARDWARE SUPPORTED AUDIO FILES
The third part of the ACM is probably the most significant. It is called the Sound
Mapper and allows audio data formats that are not directly supported by your
sound card to be played and recorded. Sound Forge XP lets you use the Sound
Mapper by selecting it for Playback and Record in the Wave page of the Preferences
folder (Options menu). Additional configuration of the Sound Mapper for your
system can be done using the Windows Control Panel.
If the ACM is not installed on your computer, the Sound Mapper option will be
called the Wave Mapper instead. The Wave Mapper and Sound Mapper can be thought
of as the same device (to a computer program, they are one and the same).
However, the Sound Mapper, which requires the ACM to be installed, is much
more powerful than the Wave Mapper. Keep this in mind when you hear people
talk about the Wave Mapper and Sound Mapper.
So, what, for example, can Sound Mapper do? If you have a sound file that is
recorded at an unusual sample rate like 22,257 Hz (perhaps a file that came
from an external sampler), and the closest sample rate that your sound card
supports is 22,050 Hz, then the sound file normally could not be played.You
would have to change the sample rate of the file to 22,050 Hz before you
could play it. However, changing the sample rate (without resampling) would
cause the sound to play at a lower pitch. The Sound Mapper can play this sound
file correctly without forcing you to resample the file first. The Sound Mapper
will map the sound to the best format possible and perform the resampling in
real time.
APPENDIX E
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