waveOutGetPlaybackRate
The waveOutGetPlaybackRate
function retrieves the current playback rate for the specified waveform-audio
output device.
MMRESULT waveOutGetPlaybackRate(
|
HWAVEOUT hwo, |
|
|
LPDWORD pdwRate |
|
|
); |
|
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. |
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