1.\" $NetBSD: uaudio.4,v 1.22 2005/06/22 04:30:08 kent Exp $ 2.\" 3.\" Copyright (c) 1999 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Lennart Augustsson. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd June 22, 2005 38.Dt UAUDIO 4 39.Os 40.Sh NAME 41.Nm uaudio 42.Nd USB audio device driver 43.Sh SYNOPSIS 44.Cd "uaudio* at uhub?" 45.Cd "audio* at audiobus?" 46.Sh DESCRIPTION 47The 48.Nm 49driver provides support for 50.Tn USB 51audio class devices. 52.Pp 53A 54.Tn USB 55audio device consists of a number of components: 56input terminals (e.g. USB digital input), output terminals (e.g. 57speakers), and a number of units in between (e.g. volume control). 58The following types of units are handled by the 59.Nm 60driver and are accessible via the mixer (see 61.Xr audio 4 ) 62interface: 63.Bl -tag -width Dv -offset 3n -compact 64.It mixer 65A mixer has a number of inputs and one output. Each input has a control 66that determines its volume in the output. 67The name of the control is 68.Ar mixN-S , 69where 70.Ar N 71is a number that identifies which mixer it is and 72.Ar S 73which input. 74.It selector 75A selector unit selects one of multiple audio sources such as mic-in 76and line-in. 77The name of the control is 78.Ar selN-S1S2S3... , 79where 80.Ar N 81is a number that identifies which selector unit it is and the sequence of 82.Ar Sn 83indicates candidate units for the audio source. 84.It feature 85A feature unit changes the sound in some way, like bass, treble, 86mute, or volume. 87The name of the control is determined in a heuristic way. 88If the unit changes the sound to a speaker output terminal, 89the names of the controls may be outputs.speaker.bass, outputs.speaker.treble, 90outputs.speaker.mute, outputs.speaker, or likewise. 91.It processing 92A processing unit does one of a number of audio processing functions 93(e.g., channel up-down mixing, Dolby ProLogic, or chorus effects). 94The name of the on-off control is 95.Ar proN.M-enable , 96where 97.Ar N 98is a number that identifies which processing unit it is and 99.Ar M 100which kind. 101Depending on the type of processing unit there may be other controls 102as well. 103.It extension 104An extension unit performs some unspecified audio processing 105The name of the on-off control is 106.Ar extN-enable , 107where 108.Ar N 109is a number that identifies which processing unit it is. 110.El 111.Pp 112For more information the 113.Tn USB 114Audio class specification is indispensable 115reading. 116.Sh SEE ALSO 117The 118.Tn USB 119specifications can be found at: 120.Dv http://www.usb.org/developers/docs.html 121.Pp 122.Xr audio 4 , 123.Xr usb 4 124.Sh HISTORY 125The 126.Nm 127driver 128appeared in 129.Nx 1.5 . 130.Sh BUGS 131There is no support for multiple-endpoints audio stream, 132adaptive recording, async playback, and TYPE-II/III formats. 133.Pp 134There is the possibility that a device has multiple mixer items 135which have the same name. 136