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Diffstat (limited to 'static/freebsd/man4/snd_uaudio.4')
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diff --git a/static/freebsd/man4/snd_uaudio.4 b/static/freebsd/man4/snd_uaudio.4 new file mode 100644 index 00000000..7193c85f --- /dev/null +++ b/static/freebsd/man4/snd_uaudio.4 @@ -0,0 +1,170 @@ +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.\" $NetBSD: uaudio.4,v 1.15 2002/02/12 19:53:57 jdolecek Exp $ +.\" +.\" Copyright (c) 1999 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by Lennart Augustsson. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS +.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS +.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +.\" POSSIBILITY OF SUCH DAMAGE. +.\" +.Dd July 17, 2025 +.Dt SND_UAUDIO 4 +.Os +.Sh NAME +.Nm snd_uaudio +.Nd USB audio and MIDI device driver +.Sh SYNOPSIS +.Cd "device sound" +.Cd "device usb" +.Cd "device snd_uaudio" +.Pp +In +.Xr rc.conf 5 : +.Cd kld_list="snd_uaudio" +.Pp +In +.Xr sysctl.conf 5 : +.Cd hw.usb.uaudio.buffer_ms +.Cd hw.usb.uaudio.default_bits +.Cd hw.usb.uaudio.default_channels +.Cd hw.usb.uaudio.default_rate +.Cd hw.usb.uaudio.handle_hid +.Cd hw.usb.uaudio.debug +.Sh DESCRIPTION +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). +.Pp +If the device supports multiple configurations, and there have been no +user-supplied values specified through the +.Xr sysctl 8 +interface, the driver will select the best matching configuration supported by +the device during attach. +"Best" means the configuration with the most channels and highest quality in +sample rate and sample size. +.Pp +Refer to the +.Ql USB Audio Class Specification +for more information. +.Sh HARDWARE +The +.Nm +driver provides support for USB audio class devices and +USB MIDI class devices. +.Sh SYSCTL VARIABLES +The following settings can be entered at the +.Xr loader 8 +prompt or in +.Xr loader.conf 5 +and can also be changed at runtime with the +.Xr sysctl 8 +command. +For a change to take effect during runtime, the device has to be re-attached. +.Bl -tag -width indent +.It Va hw.usb.uaudio.buffer_ms +Period of audio data processed at once, in milliseconds, from 1 to 8 (default +is 4). +Lower values mean less latency, but this can result in audible gaps due to +frequent CPU wakeups. +.It Va hw.usb.uaudio.default_bits +Preferred sample size in bits, from 0 to 32 (default is 0). +A value of 0 sets the sample size to the maximum supported sample size. +.Pp +Set this to select a smaller sample size if the device supports multiple sample +sizes. +.It Va hw.usb.uaudio.default_channels +Preferred number of sample channels, from 0 to 64 (default is 0). +USB 1.1 devices are limited to 4 channels due to bandwidth constraints, unless +a higher value is explicitly requested. +A value of 0 sets the sample channels to the maximum supported channel number. +.Pp +Set this to select a smaller channel number if the device supports multiple +channel configurations. +.It Va hw.usb.uaudio.default_rate +Preferred sample rate in Hz (default is 0). +If set to 0, the device's highest supported sample rate will be used. +.Pp +Note that if VCHANs are enabled, the sample rate will be overridden by +.Pa dev.pcm.%d.[play|rec].vchanrate +(see +.Xr sound 4 ) , +which can also be used to adjust the sample rate during runtime. +.Pp +If +.Pa hw.usb.uaudio.default_rate +is non-zero, +.Pa dev.pcm.%d.[play|rec].vchanrate +will use it as its maximum allowed value. +.It Va hw.usb.uaudio.handle_hid +Let +.Nm +handle HID volume keys, if any (default is 1). +.Bl -tag -width 2n +.It 0 +Disabled. +.It 1 +Enabled. +.El +.El +.Pp +If +.Xr usb 4 +has been compiled with +.Va USB_DEBUG +on, the following setting is also available: +.Bl -tag -width indent +.It Va hw.usb.uaudio.debug +Debug output level (default is 0). +.El +.Sh SEE ALSO +.Xr sound 4 , +.Xr usb 4 , +.Xr loader.conf 5 , +.Xr loader 8 , +.Xr sysctl 8 +.Rs +.%T "USB Audio Class Specifications" +.%U http://www.usb.org/developers/docs/devclass_docs/ +.Re +.Sh HISTORY +The +.Nm +driver first appeared in +.Fx 4.7 . +.Sh AUTHORS +This manual page was adopted from +.Nx 1.6 +and modified for +.Fx +by +.An Hiten Pandya Aq Mt hmp@FreeBSD.org . +.Sh BUGS +The PCM framework in +.Fx +currently does not support the full set of USB audio mixer controls. +Some mixer controls are only available as +.Va dev.pcm.%d.mixer +sysctls. |