This message is sent to a waveform output device driver to set the pitch rate for a device.
DWORD dwParam1
Specifies the new pitch rate setting. The rate is specified as a fixed-point value. The high-order word of the DWORD contains the signed integer part of the number, and the low-order word contains the fractional part. The fraction is expressed as a WORD in which a value of 0x8000 represents one half, and 0x4000 represents one quarter. For example, the value 0x00010000 specifies a multiplier of 1.0 (no pitch change), and a value of 0x000F8000 specifies a multiplier of 15.5.
DWORD dwParam2
Unused.
The return value is an error code, or zero (MMSYSERR_NOERROR) if the operation is successful. Possible error codes are:
MMSYSERR_NOTENABLED
The driver failed to load or initialize.
MMSYSERR_NOTSUPPORTED
The driver does not support changes to the pitch rate.
Driver support for pitch rate changes is optional. When a driver receives a WODM_GETDEVCAPS message, it should indicate support for pitch rate changes by setting or clearing the WAVECAPS_PITCH bit in the dwSupport field of the WAVEOUTCAPS data structure. If a driver supports the WODM_SETPITCH message, then it must also support WODM_GETPITCH.
Changes to the pitch rate alter the pitch of a waveform during playback and are usually performed by the waveform output hardware. If the hardware does not support this feature, the driver can choose to implement playback rate changes instead.