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mixerOpen The mixerOpen function opens a specified mixer device and ensures that the device will not be removed until the application closes the handle.
VB4-32,5,6
Declare Function mixerOpen Lib "winmm.dll" Alias "mixerOpen" (phmx As Long, ByVal uMxId As Long, ByVal dwCallback As Long, ByVal dwInstance As Long, ByVal fdwOpen As Long) As Long |
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Operating Systems Supported |
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Requires Windows NT 3.1 or later; Requires Windows 95 or later |
- phmx
Address of a variable that will receive a handle identifying the opened mixer device. Use this handle to identify the device when calling other audio mixer functions. This parameter cannot be NULL.
- uMxId
Identifier of the mixer device to open. Use a valid device identifier or any HMIXEROBJ (see the mixerGetID function for a description of mixer object handles). A “mapper” for audio mixer devices does not currently exist, so a mixer device identifier of - 1 is not valid.
- dwCallback
Handle of a window called when the state of an audio line and/or control associated with the device being opened is changed. Specify zero for this parameter if no callback mechanism is to be used.
- dwInstance
User instance data passed to the callback function. This parameter is not used with window callback functions.
- fdwOpen
Flags for opening the device. The following values are defined:
CALLBACK_WINDOW
The dwCallback parameter is assumed to be a window handle.
MIXER_OBJECTF_AUX
The uMxId parameter is an auxiliary device identifier in the range of zero to one less than the number of devices returned by the auxGetNumDevs function.
MIXER_OBJECTF_HMIDIIN
The uMxId parameter is the handle of a MIDI input device. This handle must have been returned by the midiInOpen function.
MIXER_OBJECTF_HMIDIOUT
The uMxId parameter is the handle of a MIDI output device. This handle must have been returned by the midiOutOpen function.
MIXER_OBJECTF_HMIXER
The uMxId parameter is a mixer device handle returned by the mixerOpen function. This flag is optional.
MIXER_OBJECTF_HWAVEIN
The uMxId parameter is a waveform-audio input handle returned by the waveInOpen function.
MIXER_OBJECTF_HWAVEOUT
The uMxId parameter is a waveform-audio output handle returned by the waveOutOpen function.
MIXER_OBJECTF_MIDIIN
The uMxId parameter is the identifier of a MIDI input device. This identifier must be in the range of zero to one less than the number of devices returned by the midiInGetNumDevs function.
MIXER_OBJECTF_MIDIOUT
The uMxId parameter is the identifier of a MIDI output device. This identifier must be in the range of zero to one less than the number of devices returned by the midiOutGetNumDevs function.
MIXER_OBJECTF_MIXER
The uMxId parameter is a mixer device identifier in the range of zero to one less than the number of devices returned by the mixerGetNumDevs function. This flag is optional.
MIXER_OBJECTF_WAVEIN
The uMxId parameter is the identifier of a waveform-audio input device in the range of zero to one less than the number of devices returned by the waveInGetNumDevs function.
MIXER_OBJECTF_WAVEOUT
The uMxId parameter is the identifier of a waveform-audio output device in the range of zero to one less than the number of devices returned by the waveOutGetNumDevs function. |
Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error values include the following:
MMSYSERR_ALLOCATED
The specified resource is already allocated by the maximum number of clients possible.
MMSYSERR_BADDEVICEID
The uMxId parameter specifies an invalid device identifier.
MMSYSERR_INVALFLAG
One or more flags are invalid.
MMSYSERR_INVALHANDLE
The uMxId parameter specifies an invalid handle.
MMSYSERR_INVALPARAM
One or more parameters are invalid.
MMSYSERR_NODRIVER
No mixer device is available for the object specified by uMxId. Note that the location referenced by uMxId will also contain the value - 1.
MMSYSERR_NOMEM
Unable to allocate resources. |
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