waveInOpen

The waveInOpen function opens the given waveform-audio input device for
recording.
MMRESULT waveInOpen(
LPHWAVEIN phwi,
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UINT uDeviceID,
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LPWAVEFORMATEX pwfx,
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DWORD dwCallback,
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DWORD dwCallbackInstance,
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DWORD fdwOpen
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);
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Parameters
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phwi
-
Address filled with a handle identifying the open waveform-audio input device.
Use this handle to identify the device when calling other waveform-audio input
functions. This parameter can be NULL if WAVE_FORMAT_QUERY is specified for fdwOpen.
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uDeviceID
-
Identifier of the waveform-audio input device to open. It can be either a
device identifier or a handle of an open waveform-audio input device.You can
use the following flag instead of a device identifier:
-
WAVE_MAPPER
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The function selects a waveform-audio input device capable of recording in the
specified format.
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pwfx
-
Address of a WAVEFORMATEX structure
that identifies the desired format for recording waveform-audio data. You can
free this structure immediately after waveInOpen returns.
-
dwCallback
-
Address of a fixed callback function, an event handle, a handle to a window,
or the identifier of a thread to be called during waveform-audio recording to
process messages related to the progress of recording. If no callback function
is required, this value can be zero. For more information on the callback
function, see waveInProc.
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dwCallbackInstance
-
User-instance data passed to the callback mechanism. This parameter is not
used with the window callback mechanism.
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fdwOpen
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Flags for opening the device. The following values are defined:
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CALLBACK_EVENT
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The dwCallback parameter is an event handle.
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CALLBACK_FUNCTION
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The dwCallback parameter is a callback procedure address.
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CALLBACK_NULL
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No callback mechanism. This is the default setting.
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CALLBACK_THREAD
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The dwCallback parameter is a thread identifier.
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CALLBACK_WINDOW
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The dwCallback parameter is a window handle.
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WAVE_FORMAT_DIRECT
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If this flag is specified, the ACM driver does not perform conversions on the
audio data.
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WAVE_FORMAT_QUERY
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The function queries the device to determine whether it supports the given
format, but it does not open the device.
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WAVE_MAPPED
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The uDeviceID parameter specifies a waveform-audio device to be mapped
to by the wave mapper.
Return Values
Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error
values include the following:
MMSYSERR_ALLOCATED
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Specified resource is already allocated.
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MMSYSERR_BADDEVICEID
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Specified device identifier is out of range.
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MMSYSERR_NODRIVER
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No device driver is present.
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MMSYSERR_NOMEM
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Unable to allocate or lock memory.
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WAVERR_BADFORMAT
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Attempted to open with an unsupported waveform-audio format.
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Remarks
Use the waveInGetNumDevs function to
determine the number of waveform-audio input devices present on the system.
The device identifier specified by uDeviceID varies from zero to one
less than the number of devices present. The WAVE_MAPPER constant can also be
used as a device identifier.
If you choose to have a window or thread receive callback information, the
following messages are sent to the window procedure or thread to indicate the
progress of waveform-audio input: MM_WIM_OPEN, MM_WIM_CLOSE, and MM_WIM_DATA.
If you choose to have a function receive callback information, the following
messages are sent to the function to indicate the progress of waveform-audio
input: WIM_OPEN, WIM_CLOSE, and WIM_DATA.
See Also
WAVEFORMATEX, waveInGetNumDevs,
waveInProc, MM_WIM_OPEN,
MM_WIM_CLOSE, MM_WIM_DATA
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