Ioctl Requests                                  audio_support(7I)

NAME
     audio_support - audio driver support routines and interface

SYNOPSIS
     #include <sys/audio.h>

DESCRIPTION
     The audio support driver supports audio drivers that use the
     new audio driver audio driver architecture. It also provides
     a limited number of ioctl(2)s for application programmers.

DATA STRUCTURES
     The following data structures are defined to manage the dif-
     ferent audio devices types and their channels.

  Device Types
     The following enumeration lists a number of  generic  device
     types.

          typedef enum {
               UNDEFINED, AUDIO, AUDIOCTL, USER1, USER2, USER3
          } audio_device_type_e;

     At this time, Solaris implements only the AUDIO and AUDIOCTL
     audio device types, using the audio mixer, see mixer(7I) for
     details. The USER1, USER2,  and  USER3  device  types  allow
     third  parties  to  write audio personality modules of their
     own.

  Channel Structure
     This structure is used to get and set state  information  on
     individual channels.

          struct audio_channel {
               pid_t     pid; /* application's porcess ID */
               uint_t    ch_number;     /* channel this device is using */
               audio_device_type_e dev_type; /* the device type */
               uint_t    info_size;     /* size of the channel's info structure */
               void *info;    /* the channel's state information */
          } audio_channel_t;

     The ch_number must be set to the specific channel number  to
     get  or  set.  When the ioctl() returns the pid will contain
     the process ID of the process that has the channel open  and
     dev_type  will  contain  the type of the device. If pid is 0
     (zero), then the channel is not open. The pointer info  must
     point to a buffer large enough to hold whatever audio device
     related state structure may be returned. At this time  there
     is  only  the  audio_info_t structure, see the audio(7I) and
     mixer(7I) man pages.

SunOS 5.8         Last change: 21 January 1999                  1

Ioctl Requests                                  audio_support(7I)

IOCTLS
     The audio support driver provides the following ioctls():

     AUDIO_GET_CH_NUMBER
           This ioctl()  returns  the  channel  number  the  file
           descriptor represents in the integer pointed to by the
           ioctl() argument.

     AUDIO_GET_CH_TYPE
           This ioctl() returns the type of channel  the  process
           has   open  via  the  audio_device_type_e  enumeration
           pointed to by the ioctl() argument.

     AUDIO_GET_NUM_CHS
           This ioctl() returns the number of channels the device
           supports  in  the  integer  pointed  to by the ioctl()
           argument.

MACROS
     The following macro can be used to  initialize  data  struc-
     tures.   The   established  convention  is  that  the  state
     corresponding to a field set to -1 will not be modified.

          AUDIO_INIT(I, S)

     Where I is a pointer to an info structure and S is the  size
     of that structure.

     The following code segment  demonstrates  how  to  use  this
     macro:

          audio_info_t    info;
          AUDIO_INIT(&info, sizeof(info));
          info.play.port = AUDIO_HEADPHONE;
          err = ioct(audio_fd, AUDIO_SETINFO, &info);

ERRORS
     EINVAL
           The ioctl() is invalid for this file  descriptor,  the
           audio_channel_t structure's info pointer doesn't point
           to a buffer or the ch_number is bad.

     ENOMEM
           The ioctl() failed due to lack of memory.

FILES
     /usr/demo/SOUND
           audio demonstration programs and other files

ATTRIBUTES

SunOS 5.8         Last change: 21 January 1999                  2

Ioctl Requests                                  audio_support(7I)

     See attributes(5) for a description of the following  attri-
     butes:

     _____________________________________________________________
    |       ATTRIBUTE TYPE        |        ATTRIBUTE VALUE       |
    | Architecture                | SPARC                        |
    | Availability                | SUNWaudd, SUNWauddx, SUNWaudh|
    | Stability Level             | Evolving                     |
    |_____________________________|______________________________|

SEE ALSO
     ioctl(2), open(2), audio(7I) mixer(7I) streamio(7I)

FUTURE DIRECTIONS
     Over time additional  audio  personallity  modules  will  be
     added.  The  audio  application  programmer is encouraged to
     review this man page on each Solaris release for  new  audio
     personality modules.

SunOS 5.8         Last change: 21 January 1999                  3