midiOutGetVolume
The midiOutGetVolume
function retrieves the current volume setting of a MIDI output device.
MMRESULT midiOutGetVolume(
|
HMIDIOUT hmo, |
|
|
LPDWORD lpdwVolume |
|
|
); |
|
Parameters
hmo
Handle of an
open MIDI output device. This parameter can also contain the handle of a MIDI
stream, as long as it is cast to HMIDIOUT. This parameter can also be a
device identifier.
lpdwVolume
Address of
the location to contain the current volume setting. The low-order word of this
location contains the left-channel volume setting, and the high-order word
contains the right-channel setting. A value of 0xFFFF represents full volume,
and a value of 0x0000 is silence.
If a device
does not support both left and right volume control, the low-order word of the
specified location contains the mono volume level.
Any value set
by using the midiOutSetVolume
function is returned, regardless of whether the device supports that value.
Return Values
Returns
MMSYSERR_NOERROR if successful or an error otherwise. Possible error values
include the following:
|
MMSYSERR_INVALHANDLE |
The
specified device handle is invalid. |
|
MMSYSERR_INVALPARAM |
The
specified pointer or structure is invalid. |
|
MMSYSERR_NOMEM |
The system
is unable to allocate or lock memory. |
|
MMSYSERR_NOTSUPPORTED |
The
function is not supported. |
Remarks
If a device
identifier is used, then the result of the midiOutGetVolume call and the
information returned in lpdwVolume applies to all instances of the
device. If a device handle is used, then the result and information returned
applies only to the instance of the device referenced by the device handle.
Not all
devices support volume control. You can determine whether a device supports
volume control by querying the device by using the midiOutGetDevCaps
function and specifying the MIDICAPS_VOLUME flag.
You can also
determine whether the device supports volume control on both the left and right
channels by querying the device by using the midiOutGetDevCaps function
and specifying the MIDICAPS_LRVOLUME flag.
See Also