Miles Sound System SDK 7.2a

AIL_sample_low_pass_cut_off

The function AIL_sample_low_pass_cut_off retrieves the current low-pass cutoff setting.

F32 AIL_sample_low_pass_cut_off(
  HSAMPLE sample
);

In Parameters

sample: specifies the digital sample that you wish to query.

Returns

returns the current low-pass filter cutoff frequency. The range is 0.0 to 1.0, given as a fraction of the sample's Nyquist rate.

Discussion

A low-pass filter attenuates frequencies above the cutoff frequency.

The default low-pass cutoff is 1.0 (allowing all frequencies to pass).

The range is 0.0 to 1.0, given as a fraction of the sample's Nyquist rate (which is half the sample rate). For example, if you have a 44100 Hz sample, then the Nyquist rate is 22050 Hz. If you then set a 0.5 cutoff factor, only frequencies under 11025 Hz will be perceived near their original amplitude.

There is almost no CPU hit at all with this filter. There is no CPU hit at all on the original Xbox, but the hardware low-pass filter only supports frequencies from 30 to 8000 Hz.

Group: Digital Audio Services
Related Functions: AIL_sample_volume_levels, AIL_sample_volume_pan, AIL_set_sample_low_pass_cut_off
Related Basic Types: F32, HSAMPLE