1.\" 2.\" Copyright (c) 2026 Abdelkader Boudih <freebsd@seuros.com> 3.\" 4.\" SPDX-License-Identifier: BSD-2-Clause 5.\" 6.Dd July 12, 2026 7.Dt FWISOUND 4 8.Os 9.Sh NAME 10.Nm fwisound 11.Nd Apple FireWire audio driver 12.Sh SYNOPSIS 13.Cd "device firewire" 14.Cd "device fwisound" 15.Cd "device sound" 16.Sh DESCRIPTION 17The 18.Nm 19driver provides audio capture from Apple FireWire devices that use a 20proprietary isochronous audio protocol 21.Pq not IEC 61883/AMDTP . 22.Pp 23The driver attaches to unit directories in the device CSR configuration ROM 24with Apple OUI 25.Pq 0x000a27 26and decodes the 27.Qq sght 28packet signature to deliver stereo PCM audio to the 29.Xr sound 4 30framework. 31.Pp 32The device attaches as a standard 33.Xr sound 4 34capture device accessible at 35.Pa /dev/dspX . 36The fixed audio format is 48000\~Hz, 2-channel, signed 16-bit big-endian 37.Pq S16BE . 38.Sh HARDWARE 39The 40.Nm 41driver supports Apple FireWire devices with the following unit directory: 42.Pp 43.Bl -tag -width "unit_sw_version" -compact 44.It Va unit_spec_ID 450x000a27 46.Pq Apple OUI 47.It Va unit_sw_version 480x000010 49.El 50.Pp 51Known compatible hardware: 52.Pp 53.Bl -bullet -compact 54.It 55Apple iSight (FireWire cylinder) 56.El 57.Sh SYSCTLS 58.Bl -tag -width ".Va hw.firewire.fwisound.iso_channel" 59.It Va hw.firewire.fwisound.iso_channel 60Isochronous receive channel (default 1). 61Can be set as a tunable in 62.Xr loader.conf 5 . 63Must not conflict with 64.Va hw.firewire.fwcam.iso_channel 65.Pq default 0 . 66.El 67.Sh FILES 68.Bl -tag -width ".Pa /dev/dspX" -compact 69.It Pa /dev/dspX 70PCM capture device created by 71.Xr sound 4 . 72.El 73.Sh EXAMPLES 74Record five seconds of audio: 75.Bd -literal -offset indent 76rec -r 48000 -c 2 -e signed-integer -b 16 -B /tmp/out.wav trim 5 77.Ed 78.Pp 79If multiple sound devices are present, address the device explicitly: 80.Bd -literal -offset indent 81sox -t ossdsp /dev/dsp4 -r 48000 -c 2 -e signed-integer -b 16 \e 82 /tmp/out.wav trim 5 83.Ed 84.Sh SEE ALSO 85.Xr firewire 4 , 86.Xr fwohci 4 , 87.Xr sound 4 , 88.Xr sysctl 8 89.Sh HISTORY 90The 91.Nm 92driver first appeared in 93.Fx 16.0 . 94.Sh AUTHORS 95.An Abdelkader Boudih Aq Mt freebsd@seuros.com 96.Pp 97Protocol reverse-engineered by Clemens Ladisch. 98