Microsoft Windows CE 3.0  

WODM_SETPLAYBACKRATE

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This message is used in an MMDRV_MESSAGE_PARAMSstructure passed to the WAV_IOControlfunction to request a waveform output driver to set the 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
A DWORDcontaining the playback rate multiplier value. This is specified as a fixed-point value, where the high-order WORDof the DWORDcontains the signed integer part of the number and the low-order WORDcontains the fractional part. The fraction consists of a WORDvalue, for which 0x8000 represents one-half and 0x4000 represents one-fourth. For example, the value 0x00010000 specifies a multiplier of 1.0, with no rate 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 WAVEERR error values declared in the Mmsystem.h header file.

Remarks

The ACM sends this message by calling the audio driver's WAV_IOControlentry point through the DeviceIoControlfunction.

Support for this message by drivers is optional. However, if a driver supports this message, it must support WODM_GETPLAYBACKRATE. Additionally, in response to the WODM_GETDEVCAPS message, it must set WAVECAPS_PLAYBACKRATE in the dwSupportmember of the WAVEOUTCAPSstructure.

Requirements

Runs on Versions Defined in Include Link to
Windows CE OS 1.0 and later      
Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.


 Last updated on Tuesday, July 13, 2004

© 2004 Microsoft Corporation. All rights reserved.