uaudio(4) - NetBSD Manual Pages

UAUDIO(4)                 NetBSD Programmer's Manual                 UAUDIO(4)


NAME

     uaudio - USB audio device driver


SYNOPSIS

     uaudio* at uhub?
     audio*  at uaudio?


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 an 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
                 Not implemented yet.
        feature  A feature unit changes the sound in some way, like bass, tre-
                 ble, or volume.  The name of the control is feaN-S-F, where N
                 is a number that identifies which feature unit it is, S which
                 input, and F which feature is affected.
        processing
                 A processing unit does one of a number of audio processing
                 functions (e.g., channel up-down mixing, Dolby ProLogic, or
                 chorus 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 pro-
                 cessing 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.


BUGS

     The mixer interface is really incomplete.

     There should be some heuristics that allows important controls, e.g.,
     volume, to be identified and given its traditional name.


SEE ALSO

     The USB specifications can be found at
     http://www.usb.org/developers/docs.htm.

     audio(4), usb(4)


HISTORY

     The uaudio driver appeared in NetBSD 1.5.

NetBSD 1.5                       July 12, 1998                               1