uaudio(4) [netbsd man page]

UAUDIO(4)						   BSD Kernel Interfaces Manual 						 UAUDIO(4)

NAME

     uaudio -- USB audio device driver

SYNOPSIS

     uaudio* at uhub?
     audio*  at audiobus?

DESCRIPTION

     The uaudio driver provides support for USB audio class devices.

     A USB audio device consists of a number of components: input terminals (e.g. USB digital input), output terminals (e.g.  speakers), and a
     number of units in between (e.g. volume control).	The following types of units are handled by the uaudio driver and are accessible via the
     mixer (see audio(4)) interface:
	mixer	      A mixer has a number of inputs and one output.  Each input has a control that determines its volume in the output.  The name
		      of the control is mixN-S, where N is a number that identifies which mixer it is and S which input.
	selector      A selector unit selects one of multiple audio sources such as mic-in and line-in.  The name of the control is
		      selN-S1S2S3..., where N is a number that identifies which selector unit it is and the sequence of Sn indicates candidate
		      units for the audio source.
	feature       A feature unit changes the sound in some way, like bass, treble, mute, or volume.  The name of the control is determined in
		      a heuristic way.	If the unit changes the sound to a speaker output terminal, the names of the controls may be out-
		      puts.speaker.bass, outputs.speaker.treble, outputs.speaker.mute, outputs.speaker, or likewise.
	processing    A processing unit does one of a number of audio processing functions (e.g., channel up-down mixing, Dolby ProLogic, or cho-
		      rus effects).  The name of the on-off control is proN.M-enable, where N is a number that identifies which processing unit it
		      is and M which kind.  Depending on the type of processing unit there may be other controls as well.
	extension     An extension unit performs some unspecified audio processing The name of the on-off control is extN-enable, where N is a
		      number that identifies which processing unit it is.

     For more information the USB Audio class specification is indispensable reading.

SEE ALSO

     audio(4), usb(4)

     USB Approved Class Specification Documents, http://www.usb.org/developers/devclass_docs/.

HISTORY

     The uaudio driver appeared in NetBSD 1.5.

BUGS

     There is no support for multiple-endpoints audio stream, adaptive recording, async playback, and TYPE-II/III formats.

     There is the possibility that a device has multiple mixer items which have the same name.

BSD
								September 20, 2011							       BSD

mixerctl(1)							   User Commands						       mixerctl(1)

NAME

       mixerctl - audio mixer control command line application

SYNOPSIS

       /usr/sbin/mixerctl [-a | -d dev]  [-iv] [-e | -o]

DESCRIPTION

       Some audio devices support the audio mixer functionality. See mixer(7I) for a complete description of the audio mixer. The mixerctl command
       is used to control the mode of the audio mixer and to get information about the audio  mixer  and  the  audio  device.  See  audio(7I)  for
       details.

OPTIONS

       The following options are supported. If none are specified, option -i is assumed:

       -a	       The command applies to all audio devices.

       -d dev	       The dev argument specifies an alternate audio control device for the command to use.

       -e	       Enables the audio mixer function if the audio device supports it. If supported, the audio mixer may be enabled at any time.
		       The command silently ignores the enable option if the audio mixer is already enabled.

       -i	       Prints the audio device type information for the device and indicates whether the audio device uses the audio mixer. If the
		       device does use the audio mixer, this option displays the audio mixer's mode.

       -o	       Turns off the audio mixer function if the audio device supports it. If supported, the audio mixer may be turned off if only
		       one process has the device opened with the O_RDWR flag, or, if two different processes have the device opened, one with the
		       O_RDONLY  flag  and the other with the O_WRONLY flag. (See open(2).) The command silently ignores the disable option if the
		       audio mixer function is already disabled.

       -v	       Verbose mode. Prints the audio_info_t structure for the device, along with the device type information. This option implies
		       the -i option.

ENVIRONMENT VARIABLES

       AUDIODEV        If  the	-d and -a options are not specified, the AUDIODEV environment variable is consulted. If set, AUDIODEV will contain
		       the full path name of the user's default audio device. The default audio device will be converted into  a  control  device,
		       and then used. If the AUDIODEV variable is not set, /dev/audioctl is used.

FILES

       /dev/audioctl

       /dev/sound/{0...n}ctl

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |SPARC, x86		   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWauda			   |
       +-----------------------------+-----------------------------+
       |Stability Level 	     |Evolving			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       audioconvert(1), audioplay(1), audiorecord(1), open(2), attributes(5), usb_ac(7D), audio(7I), audio_support(7I), mixer(7I)

SunOS 5.10							    12 Mar 2001 						       mixerctl(1)