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waveOutGetPlaybackRate
The waveOutGetPlaybackRate function retrieves the current playback rate for the specified waveform-audio
output device.
MMRESULT waveOutGetPlaybackRate(
HWAVEOUT hwo,
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| LPDWORD pdwRate
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| );
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Parameters
hwo
Handle of the waveform-audio output device.
pdwRate
Address of a variable to be filled with the current playback rate. The
playback rate 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 of the
variable 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.
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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
WAVEOUTCAPS, waveOutGetDevCaps
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