waveOutSetPlaybackRate
The waveOutSetPlaybackRate
function sets the playback rate for the specified waveform-audio output device.
MMRESULT waveOutSetPlaybackRate(
|
HWAVEOUT hwo, |
|
|
DWORD dwRate |
|
|
); |
|
Parameters
hwo
Handle of the
waveform-audio output device.
dwRate
New playback
rate setting. This setting is a multiplier indicating the current change in
playback rate from the original authored setting. The playback rate multiplier
must be a positive value.
The rate is
specified as a fixed-point value. The high-order word contains the signed
integer part of the number, and the low-order word contains the fractional
part. A value of 0x8000 in the low-order word represents one-half, and 0x4000
represents one-quarter. For example, the value 0x00010000 specifies a
multiplier of 1.0 (no playback rate change), and a value of 0x000F8000
specifies a multiplier of 15.5.
Return Values
Returns
MMSYSERR_NOERROR if successful or an error otherwise. Possible error values
include the following:
|
MMSYSERR_INVALHANDLE |
Specified
device handle is invalid. |
|
MMSYSERR_NODRIVER |
No device
driver is present. |
|
MMSYSERR_NOMEM |
Unable to
allocate or lock memory. |
|
MMSYSERR_NOTSUPPORTED |
Function
isn t supported. |
Remarks
Changing the
playback rate does not change the sample rate but does change the playback
time. Not all devices support playback rate changes. To determine whether a
device supports playback rate changes, use the WAVECAPS_PLAYBACKRATE flag to
test the dwSupport member of the WAVEOUTCAPS structure (filled by
the waveOutGetDevCaps function).
See Also