The auxGetDevCaps function retrieves the capabilities of a given auxiliary output device.

MMRESULT auxGetDevCaps(
  UINT_PTR  uDeviceID, 
  LPAUXCAPS lpCaps,    
  UINT      cbCaps     



Identifier of the auxiliary output device to be queried. Specify a valid device identifier (see the following comments section), or use the following constant:

Value Meaning
AUX_MAPPER Auxiliary audio mapper. The function returns an error if no auxiliary audio mapper is installed.


Pointer to an AUXCAPS structure to be filled with information about the capabilities of the device.


Size, in bytes, of the AUXCAPS structure.

Return Values

Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error values include the following.

Value Description
MMSYSERR_BADDEVICEID Specified device identifier is out of range.


The device identifier in uDeviceID varies from zero to one less than the number of devices present. AUX_MAPPER may also be used. Use the auxGetNumDevs function to determine the number of auxiliary output devices present in the system.


**  Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
**  Windows 95/98/Me:** Included in Windows 95 and later.
**  Header:** Declared in Mmsystem.h; include Windows.h.
**  Library:** Use Winmm.lib.
**  Unicode:** Implemented as Unicode and ANSI versions on Windows NT/2000/XP.

See Also

Waveform Audio, Waveform Functions, AUXCAPS, auxGetNumDevs