View source for MCI MIXSETUP

{{DISPLAYTITLE:MCI_MIXSETUP}}
This message informs the mixer device that the application wishes to read or write buffers directly and sets up the device in the correct mode (for example, PCM, MPEG audio or MIDI).

==Syntax==
<PRE>
param1
ULONG ulParam1; /* Flags for mixer setup operation. */

param2
PMCI_MIXSETUP_PARMS pParam2; /* Pointer to the MCI_MIXSETUP_PARMS data structure. */
</PRE>

==Parameters==
;''ulParam1'' ([[ULONG]]) - input
:This parameter can contain any of the following flags:
:* '''MCI_NOTIFY''' A notification message is posted to the window specified in the ''hwndCallback'' field of the data structure identified by ''pParam2'' when the action indicated by this message is completed.
:* '''MCI_WAIT''' Control is not returned until the action indicated by this message is completed.
:* '''MCI_MIXSETUP_INIT''' Initializes the mixer for the correct mode according to the value specified in the ''ulFormatMode'' field of [[MCI_MIXSETUP_PARMS]].
:* '''MCI_MIXSETUP_DEINIT''' Deinitializes the mixer.
:* '''MCI_MIXSETUP_QUERYMODE''' Queries a device to see if a specific mode is supported.

;''pParam2'' ([[PMCI_MIXSETUP_PARMS]]) - input
:A pointer to the [[MCI_MIXSETUP_PARMS]] data structure.

==Returns==
;''rc'' ([[ULONG]]) - returns
:Return codes indicating success or type of failure:
:* '''MCIERR_SUCCESS''' Command completed successfully.
:* '''MCIERR_INVALID_DEVICE_ID''' Invalid device ID given.
:* '''MCIERR_MISSING_PARAMETER''' Required parameter is missing.
:* '''MCIERR_INVALID_MODE''' Device mode invalid for this command.
:* '''MCIERR_INVALID_DEVICE_TYPE''' Mixer does not support the requested device type.
:* '''MCIERR_INVALID_FLAG''' Invalid flag specified for this command.

==Remarks==
On input, the application must fill in the ''ulDeviceType'' field of the [[MCI_MIXSETUP_PARMS]] structure to inform the mixer of the media type it will be sending. The application must also fill in the ''pmixEvent'' field of the [[MCI_MIXSETUP_PARMS]] structure with a callback function for the mixer to call when it is finished writing or reading a buffer.

If the call is successful, the mixer will update the ''pmixWrite'' and ''pmixRead'' fields so that the application can write or read buffers to or from the mixer. In addition, the mixer will update the ''ulBufferSize'' and ''ulNumBuffers'' fields with the **suggested** buffer size and number of buffers to use with the requested setup. The application does not have to use these suggested values as they are simply recommendations.

If the mixer has already been initialized with **MCI_MIXSETUP** and **MCI_MIXSETUP** is called again, **MCIERR_INVALID_MODE** will be returned.

After **MCI_MIXSETUP** has been successfully called, you can use [[MCI_BUFFER]] to allocate or deallocate memory for communcation with the audio device.

==Example Code==
<PRE>
    memset( &MixSetupParms, '\0', sizeof( MCI_MIXSETUP_PARMS ) );

    MixSetupParms.ulBitsPerSample = 16;
    MixSetupParms.ulFormatTag = MCI_WAVE_FORMAT_PCM;
    MixSetupParms.ulSamplesPerSec = 22050;
    MixSetupParms.ulChannels = 2;  /* Stereo */
    MixSetupParms.ulBitsPerSample = 16;
    MixSetupParms.ulFormatMode = MCI_PLAY;
    MixSetupParms.ulDeviceType = MCI_DEVTYPE_WAVEFORM_AUDIO;

    /* The mixer will inform us of entry points to */
    /* read/write buffers to and also give us a    */
    /* handle to use with these entry points.      */

    MixSetupParms.pmixEvent = MyEvent;

    rc = mciSendCommand( usDeviceID,
                         MCI_MIXSETUP,
                         MCI_WAIT | MCI_MIXSETUP_INIT,
                         ( PVOID ) &MixSetupParms,
                         0 );
</PRE>

== Related Methods==
* [[MCI_BUFFER]]

[[Category:MCI]]