class FMOD::Effects::PitchShift

This unit bends the pitch of a sound without changing the speed of playback.

This pitch shifting unit can be used to change the pitch of a sound without speeding it up or slowing it down.

It can also be used for time stretching or scaling, for example if the pitch was doubled, and the frequency of the sound was halved, the pitch of the sound would sound correct but it would be twice as slow.

@note This filter is very computationally expensive! Similar to a vocoder,

it requires several overlapping FFT and IFFT's to produce smooth output,
and can require around 440mhz for 1 stereo 48khz signal using the
default settings.

Reducing the signal to mono will half the CPU usage.

Reducing this will lower audio quality, but what settings to use are
largely dependant on the sound being played. A noisy polyphonic signal
will need higher FFT size compared to a speaking voice for example.

@attr pitch [Float] Pitch value.

* *Minimum:* 0.5 (one octave lower)
* *Maximum:* 2.0 (one octave higher)
* *Default:* 1.0 (normal)

@attr window_size [Float] FFT window size. Increase this to reduce

"smearing". This effect is a warbling sound similar to when an MP3 is
encoded at very low bit-rates.
* *Minimum:* 256
* *Maximum:* 4096
* *Default:* 1024
* *Valid:* 256, 512, 1024, 2048, 4096

@attr max_channels [Float] Maximum channels supported. 0 = same

as FMOD's default output polyphony, 1 = mono, 2 = stereo etc.
* *Minimum:* 0
* *Maximum:* 16
* *Default:* 0 (strongly recommended to leave at 0!)