1 .\" $NetBSD: uaudio.4,v 1.15 2002/02/12 19:53:57 jdolecek Exp $
3 .\" Copyright (c) 1999 The NetBSD Foundation, Inc.
4 .\" All rights reserved.
6 .\" This code is derived from software contributed to The NetBSD Foundation
7 .\" by Lennart Augustsson.
9 .\" Redistribution and use in source and binary forms, with or without
10 .\" modification, are permitted provided that the following conditions
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.
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.
44 .Nd USB audio and MIDI device driver
46 To compile this driver into the kernel, place the following lines in your
47 kernel configuration file:
48 .Bd -ragged -offset indent
51 .Cd "device snd_uaudio"
54 Alternatively, to load the driver as a module at boot time, place the
57 .Bd -literal -offset indent
63 driver provides support for
65 audio class devices and
71 audio device consists of a number of components:
72 input terminals (e.g.\& USB digital input), output terminals (e.g.\&
73 speakers), and a number of units in between (e.g.\& volume control).
76 .Ql USB Audio Class Specification
82 .%T "USB Audio Class Specifications"
83 .%U http://www.usb.org/developers/devclass_docs/
88 driver first appeared in
91 This manual page was adopted from
96 .An Hiten Pandya Aq hmp@FreeBSD.org .
102 only supports synchronous device detach.
103 That means all mixer and DSP character devices belonging to a given
104 USB audio device must be closed when receiving an error on a DSP read,
105 a DSP write or a DSP IOCTL request.
106 Else the USB audio driver will wait for this to happen, preventing
107 enumeration of new devices on the parenting USB controller.
109 Some USB audio devices might refuse to work properly unless the sample
110 rate is configured the same for both recording and playback, even if
111 only simplex is used.
113 .Va dev.pcm.%d.[play|rec].vchanrate
120 currently doesn't support the full set of USB audio mixer
122 Some mixer controls are only available as