audio_support(7I) Ioctl Requests audio_support(7I)NAMEaudio_support - audio driver support routines and interface
SYNOPSIS
#include <sys/audio.h>
DESCRIPTION
The audio support module supports audio drivers that use the new audio
driver architecture. It also provides a limited number of ioctl(2)
functions for application programmers.
DATA STRUCTURES
The following data structures are defined to manage the different audio
device types and 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;
Currently, the Solaris audio mixer implements only the AUDIO and
AUDIOCTL audio device types. See the mixer(7I) manual page 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 process ID */
uint_t ch_number; /* device channel */
audio_device_type_e dev_type; /* device type */
uint_t info_size; /* size of channel's */
/* info structure */
void *info; /* channel state information */
;
typedef struct audio_channel audio_channel_t;
The ch_number must specify the specific channel number to get or set.
When the ioctl() returns, the pid contains the process ID of the
process that has that channel open and dev_type will contain the device
type. 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 that may be returned. Currently, only
the audio_info_t structure is returned. See the audio(7I) and mixer(7I)
man pages for more information.
IOCTLS
The audio support driver provides the following ioctls():
AUDIO_GET_CH_NUMBER This ioctl() returns the channel number pointed
to by the file descriptor. It is returned in the
integer pointer of the ioctl() argument.
AUDIO_GET_CH_TYPE This ioctl() returns the type of channel the
process has open. It is returned in the
audio_device_type_e enumeration pointer of the
ioctl() argument.
AUDIO_GET_NUM_CHS This ioctl() returns the number of channels the
device supports. It is returned in the integer
pointer of the ioctl() argument.
MACROS
The following macro can be used to initialize data structures. 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 = ioctl(audio_fd, AUDIO_SETINFO, &info);
ERRORS
EINVAL The ioctl() is invalid for this file descriptor. The
audio_channel_t structure's info pointer does not point to a
buffer, or the ch_number is bad.
ENOMEM The ioctl() failed due to lack of memory.
FILES
/usr/share/audio/samples Audio sample files
ATTRIBUTES
See attributes(5) for a description of the following attributes:
┌────────────────────────────────────────────────────────────┐
│ATTRIBUTE TYPE ATTRIBUTE VALUE │
│Architecture SPARC, x86 │
│Availability SUNWaudd, SUNWauddx, SUNWaudh │
│Stability Level Evolving │
└────────────────────────────────────────────────────────────┘
SEE ALSOioctl(2), attributes(5), audio(7I), mixer(7I), streamio(7I)FUTURE DIRECTIONS
Over time, additional audio personality modules will be added. Audio
application programmers are encouraged to review this man page with
each Solaris release for new audio personality modules.
SunOS 5.10 16 May 2011 audio_support(7I)
