.\" .\" Copyright (c) 2026 Abdelkader Boudih .\" .\" SPDX-License-Identifier: BSD-2-Clause .\" .Dd June 19, 2026 .Dt FWISOUND 4 .Os .Sh NAME .Nm fwisound .Nd Apple FireWire audio driver .Sh SYNOPSIS .Cd "device firewire" .Cd "device fwisound" .Cd "device sound" .Sh DESCRIPTION The .Nm driver provides audio capture from Apple FireWire devices that use a proprietary isochronous audio protocol .Pq not IEC 61883/AMDTP . .Pp The driver matches FireWire units with Apple OUI .Pq 0x000a27 and decodes the .Qq sght packet signature to deliver stereo PCM audio to the .Xr sound 4 framework. .Pp The device attaches as a standard .Xr sound 4 capture device accessible at .Pa /dev/dspX . The fixed audio format is 48000\~Hz, 2-channel, signed 16-bit big-endian .Pq S16BE . .Sh HARDWARE The .Nm driver supports Apple FireWire devices with the following unit directory: .Pp .Bl -tag -width "unit_sw_version" -compact .It Va unit_spec_ID 0x000a27 .Pq Apple OUI .It Va unit_sw_version 0x000010 .El .Pp Known compatible hardware: .Pp .Bl -bullet -compact .It Apple iSight (FireWire cylinder) .El .Sh SYSCTLS .Bl -tag -width ".Va hw.firewire.fwisound.iso_channel" .It Va hw.firewire.fwisound.iso_channel Isochronous receive channel (default 1). Can be set as a tunable in .Xr loader.conf 5 . Must not conflict with .Va hw.firewire.fwcam.iso_channel .Pq default 0 . .El .Sh FILES .Bl -tag -width ".Pa /dev/dspX" -compact .It Pa /dev/dspX PCM capture device created by .Xr sound 4 . .El .Sh EXAMPLES Record five seconds of audio: .Bd -literal -offset indent rec -r 48000 -c 2 -e signed-integer -b 16 -B /tmp/out.wav trim 5 .Ed .Pp If multiple sound devices are present, address the device explicitly: .Bd -literal -offset indent sox -t ossdsp /dev/dsp4 -r 48000 -c 2 -e signed-integer -b 16 \e /tmp/out.wav trim 5 .Ed .Sh SEE ALSO .Xr firewire 4 , .Xr fwohci 4 , .Xr sound 4 , .Xr sysctl 8 .Sh HISTORY The .Nm driver first appeared in .Fx 16.0 . .Sh AUTHORS .An Abdelkader Boudih Aq Mt freebsd@seuros.com .Pp Protocol reverse-engineered by Clemens Ladisch.