.\" $NetBSD: pad.4,v 1.10 2021/02/06 12:13:44 nia Exp $
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.\" Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
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.Dd February 6, 2021
.Dt PAD 4
.Os
.Sh NAME
.Nm pad
.Nd Pseudo audio device driver
.Sh SYNOPSIS
.Cd "pseudo-device pad"
.Cd "audio* at audiobus?"
.Sh DESCRIPTION
.Nm
is a pseudo-device driver which provides support for feeding back PCM data
from consumers of an
.Xr audio 4
device to userland.
.Pp
The raw PCM data readable from
.Pa /dev/padN
is encoded in stereo little-endian 16-bit linear PCM at 44100 Hz.
.Sh FILES
The
.Nm
pseudo-device driver receives data from
.Pa /dev/audioN
and feeds the raw PCM output to
.Pa /dev/padN .
.Pa /dev/audioN
is created once
.Pa /dev/padN
is opened.
.Bl -item
.It
.Pa /dev/audioN
.It
.Pa /dev/padN
.El
.Sh EXAMPLES
The following example streams an MP3 to an Apple AirTunes compatible device:
.Bd -literal -offset indent
$ rtunes - < /dev/pad0 &
$ mpg123 -a /dev/audio1 mozart.mp3
.Ed
.Pp
Record the output of an application (in this case, audioplay):
.Bd -literal -offset indent
$ ffmpeg -f s16le -ar 44100 -ac 2 -i /dev/pad0 output.wav
$ audioplay -d /dev/audio1 input.wav
.Ed
.Sh SEE ALSO
.Xr audio 4
.Sh HISTORY
The
.Nm
driver
appeared in
.Nx 5.0 .
.Sh AUTHORS
.An Jared D. McNeill Aq Mt jmcneill@invisible.ca