WODM_GETPLAYBACKRATE (Windows Embedded CE 6.0)

1/6/2010

This message is used in an MMDRV_MESSAGE_PARAMS structure passed to the WAV_IOControl function to request a waveform output driver to return the current playback rate multiplier value for the specified device.

Parameters

• uDeviceId
  Device identifier — 0, 1, 2, and so on — for the target device.

• uMsg
  Specifies this message.

• dwUser
  Specifies a device instance identifier.

• dwParam1
  Specifies a pointer to a DWORD location used to return the current playback rate multiplier value. This is specified as a fixed-point value, where 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 consists of a WORD value, for which 0x8000 represents one-half and 0x4000 represents one-fourth. For example, the value 0x00010000 specifies a multiplier of 1.0, with no pitch change, and a value of 0x000F8000 specifies a multiplier of 15.5.

• dwParam2
  Not used.

Return Values

MMSYSERR_NOERROR indicates success. Otherwise, the driver returns one of the MMSYSERR or WAVERR error values declared in the Mmsystem.h header file.

Remarks

The waveform API manager sends this message by calling the audio driver's WAV_IOControl entry point through the DeviceIoControl function.

Support for this message by drivers is optional. However, if a driver supports the WODM_SETPLAYBACKRATE message, it must support this message.

Requirements

See Also

Reference

Waveform Output Driver Messages
WAV_IOControl
MMDRV_MESSAGE_PARAMS

Concepts

Audio Device Instances