AUDIORECORD(1) User Commands AUDIORECORD(1)

NAME

audiorecord - record an audio file

SYNOPSIS

audiorecord [-af] [-v vol] [-c channels] [-s rate]
[-e encoding] [-t time] [-i info] [-d dev]
[-T au|aif[f]|wav] [file[.au|.aif[f]|.wav]]

DESCRIPTION

The audiorecord utility copies audio data from the audio device to a
named audio file, or to the standard output if no filename is present. If
no output file is specified and standard output is a tty, the program
exits with an error message.


By default, monaural audio data is recorded at 8 kHz and encoded in u-law
format. If the audio device supports additional configurations, the -c,
-s, and -e options may be used to specify the data format. The output
file is prefixed by an audio file header that identifies the format of
the data encoded in the file.


Recording begins immediately and continues until a SIGINT signal (for
example, Control-c) is received. If the -t option is specified,
audiorecord stops when the specified quantity of data has been recorded.


If the audio device is unavailable, that is, if another process currently
has read access, audiorecord prints an error message and exits
immediately.

OPTIONS

The following options are supported:

-?
Help: Prints a command line usage message.


-a
Append: Appends the data on the end of the named
audio file. The audio device must support the
audio data format of the existing file.


-c channels
Channels: Specifies the number of audio channels
(1 or 2). The value may be specified as an
integer or as the string mono or stereo. The
default value is mono.


-d dev
Device: The dev argument specifies an alternate
audio device from which input should be taken. If
the -d option is not specified, the AUDIODEV
environment variable is consulted (see below).
Otherwise, /dev/audio is used as the default
audio device.


-e encoding
Encoding: Specifies the audio data encoding. This
value may be one of ulaw, alaw, or linear. The
default encoding is ulaw.


-f
Force: When the -a flag is specified, the sample
rate of the audio device must match the sample
rate at which the original file was recorded. If
the -f flag is also specified, sample rate
differences are ignored, with a warning message
printed on the standard error.


-i info
Information: The `information' field of the
output file header is set to the string specified
by the info argument. This option cannot be
specified in conjunction with the -a argument.


-s rate
Sample Rate: Specifies the sample rate, in
samples per second. If a number is followed by
the letter k, it is multiplied by 1000 (for
example, 44.1k = 44100). The default sample rate
is 8 kHz.


-t time
Time: The time argument specifies the maximum
length of time to record. Time can be specified
as a floating-point value, indicating the number
of seconds, or in the form: hh:mm:ss.dd, where
the hour and minute specifications are optional.


-T au | aif[f] | wav
Specifies the audio file type to create. If the
-a option is used, the file type must match the
file to which it is being appended. Regardless of
the file suffix, the type is set as specified in
this option. If this option is not specified, the
file suffix determines the type.


-v vol
Volume: The recording gain is set to the
specified value before recording begins, and is
reset to its previous level when audiorecord
exits. The vol argument is an integer value
between 0 and 100, inclusive. If this argument is
not specified, the input volume remains at the
level most recently set by any process.

OPERANDS

file[.au|.aif[f]|.wav]

File Specification: The named audio file is rewritten, or appended.
If no filename is present, and standard output is not a tty, or if
the special filename "-" is specified, output is directed to the
standard output.

If the -T option is not specified, the file suffix determines the
type of file. If the suffix is not recognized, the default is .au. If
the -T option is specified, that file type is used regardless of the
file suffix.

USAGE

See largefile(7) for the description of the behavior of audiorecord when
encountering files greater than or equal to 2 Gbyte (2^31 bytes).

ENVIRONMENT VARIABLES

AUDIODEV
The full path name of the audio device to record from, if no
-d argument is supplied. If the AUDIODEV variable is not set,
/dev/audio is used.

SEE ALSO

audioconvert(1), audioplay(1), audio(4I), largefile(7)


February 8, 2020 AUDIORECORD(1)