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ALqueryparams(3dm)					    ALqueryparams(3dm)

NAME    [Toc]    [Back]

     ALqueryparams - (obsolete)	get descriptor/description pairs for audio
     device state variables

SYNOPSIS    [Toc]    [Back]

     #include <dmedia/audio.h>

     long ALqueryparams(long device, long *PVbuffer, long bufferlength)

PARAMETER    [Toc]    [Back]

     device	    expects a device.  Currently, there	is only	one device,

     PVbuffer	    expects an array of	longs into which ALqueryparams(3dm)
		    can	write descriptor/description pairs for each state
		    variable associated	with device.  The even (0,2,4, ...)
		    entries receive the	descriptors. The odd entries (1,3,5,
		    ...) receive the descriptions.  These descriptions take on
		    one	of four	values:

		    +/-AL_RANGE_VALUE if this device state variable can	assume
		    a range of values, and the range has some meaning, i.e.
		    larger values mean more of whatever	this parameter
		    controls.  A value of -AL_RANGE_VALUE indicates that the
		    parameter is read-only.

		    +/-AL_ENUM_VALUE  if this device state variable assumes
		    values from	an enumerated type.  They still	have a limited
		    range, but there is	no inherent relationship between them.
		    A value of -AL_ENUM_VALUE indicates	that the parameter is

     bufferlength   expects the	length of the buffer, in longs,	pointed	to by

DESCRIPTION    [Toc]    [Back]

     ALqueryparams is obsolete and is provided for backward compatibility. The
     preferred method is to use	alQueryValues(3dm) with	the AL_PARAMS
     parameter to list the supported parameters, followed by
     alGetParamInfo(3dm) to get	information about each supported parameter.

     ALqueryparams(3dm)	lets you get a list of descriptors for all the state
     variables associated with the specified device.

     ALqueryparams(3dm)	also tells you whether the value of a state variable
     must be one of a set of enumerated	types or any number within a specific
     range.  In	both cases the values are numbers within the range returned by
     ALgetminmax(3dm) and have the default value returned by

									Page 1

ALqueryparams(3dm)					    ALqueryparams(3dm)

     Typical device parameters are expected to be things like volume and
     sample rate. You can find a list of parameters and	their descriptions in

     ALqueryparams(3dm)	returns	the length of the buffer (number of longs)
     that is required to hold all pairs	of descriptors/descriptions. If
     PVbuffer is smaller than this value, you have not acquired	a complete
     list of descriptor/description pairs and should increase your PVbuffer
     and try again.

     To	simply determine the size of the buffer	needed to hold the parameters
     and descriptions, call ALqueryparams(3dm) with bufferlength set to	zero.

     ALqueryparams(3dm)	can fail for the following reasons:

     AL_BAD_DEVICE	       device is not valid.

     AL_BAD_PVBUFFER	       PVbuffer	is null	valued.

     AL_BAD_BUFFERLENGTH_ODD   bufferlength is odd.

     AL_BAD_BUFFERLENGTH_NEG   bufferlength is negative.

     AL_BAD_DEVICE_ACCESS      audio hardware is inaccessible.

EXAMPLE    [Toc]    [Back]

	       #include	<dmedia/audio.h>
	       #include	<malloc.h>
	       /* Get a	buffer containing all the device parameters. */
	       long *buf,buflen;
	       buf=(long *)malloc(buflen*sizeof(long));

DIAGNOSTICS    [Toc]    [Back]

     Upon successful completion	ALqueryparams(3dm) returns the size of the
     buffer, in	longs, needed to hold all the descriptor/description pairs for
     device. Otherwise,	ALqueryparams(3dm) returns -1 and sets an error	number
     which can be retrieved with oserror(3C).

SEE ALSO    [Toc]    [Back]

     ALgetparams(3dm), ALsetparams(3dm), ALgetminmax(3dm), ALgetname(3dm),
     ALgetdefault(3dm),	ALsetdevice(3dm), oserror(3C)

									PPPPaaaaggggeeee 2222
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 Similar pages
Name OS Title
ALgetname IRIX (obsolete) returns a name for an audio device state variable
ALgetdefault IRIX (obsolete) returns the default value for an audio device state variable
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ALgetparams IRIX (obsolete) get/set the value of the specified audio device states
ALopenport IRIX (obsolete) open an audio port
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ALwritesamps IRIX (obsolete) write samples to an audio port
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