NAME
arecord, aplay - command-line sound recorder and player for ALSA
soundcard driver
SYNOPSIS
arecord [flags] [filename]
aplay [flags] [filename [filename]] ...
DESCRIPTION
arecord is a command-line soundfile recorder for the ALSA soundcard
driver. It supports several file formats and multiple soundcards with
multiple devices. If recording with interleaved mode samples the file
is automatically split before the 2GB filesize.
aplay is much the same, only it plays instead of recording. For
supported soundfile formats, the sampling rate, bit depth, and so forth
can be automatically determined from the soundfile header.
If filename is not specified, the standard output or input is used. The
aplay utility accepts multiple filenames.
OPTIONS
-h, --help
Help: show syntax.
--version
Print current version.
-l, --list-devices
List all soundcards and digital audio devices
-L, --list-pcms
List all PCMs defined
-D, --device=NAME
Select PCM by name
-q --quiet
Quiet mode. Suppress messages (not sound :))
-t, --file-type TYPE
File type (voc, wav, raw or au). If this parameter is omitted
the WAVE format is used.
-c, --channels=#
The number of channels. The default is one channel. Valid
values are 1 through 32.
-f --format=FORMAT
Sample format
Recognized sample formats are: S8 U8 S16_LE S16_BE U16_LE U16_BE
S24_LE S24_BE U24_LE U24_BE S32_LE S32_BE U32_LE U32_BE FLOAT_LE
FLOAT_BE FLOAT64_LE FLOAT64_BE IEC958_SUBFRAME_LE
IEC958_SUBFRAME_BE MU_LAW A_LAW IMA_ADPCM MPEG GSM SPECIAL
S24_3LE S24_3BE U24_3LE U24_3BE S20_3LE S20_3BE U20_3LE U20_3BE
S18_3LE S18_3BE U18_3LE
Some of these may not be available on selected hardware
The available format shortcuts are:
-f cd (16 bit little endian, 44100, stereo) [-f S16_LE -c2 -r44100]
-f cdr (16 bit big endian, 44100, stereo) [-f S16_BE -c2 -f44100]
-f dat (16 bit little endian, 48000, stereo) [-f S16_LE -c2 -r48000]
If no format is given U8 is used.
-r, --rate=#<Hz>
Sampling rate in Hertz. The default rate is 8000 Hertz. If the
value specified is less than 300, it is taken as the rate in
kilohertz. Valid values are 2000 through 192000 Hertz.
-d, --duration=#
Interrupt after # seconds. A value of zero means infinity. The
default is zero, so if this option is omitted then the arecord
process will run until it is killed.
-s, --sleep-min=#
Min ticks to sleep. The default is not to sleep.
-M, --mmap
Use memory-mapped (mmap) I/O mode for the audio stream. If this
option is not set, the read/write I/O mode will be used.
-N, --nonblock
Open the audio device in non-blocking mode. If the device is
busy the program will exit immediately. If this option is not
set the program will block until the audio device is available
again.
-F, --period-time=#
Distance between interrupts is # microseconds. If no period
time and no period size is given then a quarter of the buffer
time is set.
-B, --buffer-time=#
Buffer duration is # microseconds If no buffer time and no
buffer size is given then the maximal allowed buffer time but
not more than 500ms is set.
--period-size=#
Distance between interrupts is # frames If no period size and no
period time is given then a quarter of the buffer size is set.
--buffer-size=#
Buffer duration is # frames If no buffer time and no buffer size
is given then the maximal allowed buffer time but not more than
500ms is set.
-A, --avail-min=#
Min available space for wakeup is # microseconds
-R, --start-delay=#
Delay for automatic PCM start is # microseconds (relative to
buffer size if <= 0)
-T, --stop-delay=#
Delay for automatic PCM stop is # microseconds from xrun
-v, --verbose
Show PCM structure and setup. This option is accumulative. The
VU meter is displayed when this is given twice or three times.
-V, --vumeter=TYPE
Specifies the VU-meter type, either stereo or mono. The stereo
VU-meter is available only for 2-channel stereo samples with
interleaved format.
-I, --separate-channels
One file for each channel. This option disables max-file-time
and use-strftime, and ignores SIGUSR1. The stereo VU meter is
not available with separate channels.
-P Playback. This is the default if the program is invoked by
typing aplay.
-C Record. This is the default if the program is invoked by typing
arecord.
--disable-resample
Disable automatic rate resample.
--disable-channels
Disable automatic channel conversions.
--disable-format
Disable automatic format conversions.
--disable-softvol
Disable software volume control (softvol).
--test-position
Test ring buffer position.
--test-coef=<coef>
Test coefficient for ring buffer position; default is 8.
Expression for validation is: coef * (buffer_size / 2). Minimum
value is 1.
--test-nowait
Do not wait for the ring buffer--eats the whole CPU.
--max-file-time
While recording, when the output file has been accumulating
sound for this long, close it and open a new output file.
Default is the maximum size supported by the file format: 2 GiB
for WAV files. This option has no effect if
--separate-channels is specified.
--process-id-file <file name>
aplay writes its process ID here, so other programs can send
signals to it.
--use-strftime
When recording, interpret %-codes in the file name parameter
using the strftime facility whenever the output file is opened.
The important strftime codes are: %Y is the year, %m month, %d
day of the month, %H hour, %M minute and %S second. In
addition, %v is the file number, starting at 1. When this
option is specified, intermediate directories for the output
file are created automatically. This option has no effect if
--separate-channels is specified.
SIGNALS
When recording, SIGINT, SIGTERM and SIGABRT will close the output file
and exit. SIGUSR1 will close the output file, open a new one, and
continue recording. However, SIGUSR1 does not work with
--separate-channels.
EXAMPLES
aplay -c 1 -t raw -r 22050 -f mu_law foobar
will play the raw file "foobar" as a 22050-Hz, mono, 8-bit, Mu-
Law .au file.
arecord -d 10 -f cd -t wav -D copy foobar.wav
will record foobar.wav as a 10-second, CD-quality wave file,
using the PCM "copy" (which might be defined in the user’s
.asoundrc file as:
pcm.copy {
type plug
slave {
pcm hw
}
route_policy copy
}
arecord -t wav -max-file_time 30 mon.wav
Record from the default audio source in monaural, 8,000 samples
per second, 8 bits per sample. Start a new file every 30
seconds. File names are mon-nn.wav, where nn increases from 01.
The file after mon-99.wav is mon-100.wav.
arecord -f cd -t wav -max-file-time 3600 --use-strftime
%Y/%m/%d/listen-%H-%M-%v.wav
Record in stereo from the default audio source. Create a new
file every hour. The files are placed in directories based on
their start dates and have names which include their start times
and file numbers.
SEE ALSO
alsamixer(1), amixer(1)
BUGS
Note that .aiff files are not currently supported.
AUTHOR
arecord and aplay are by Jaroslav Kysela <perex@perex.cz> This document
is by Paul Winkler <zarmzarm@erols.com>. Updated for Alsa 0.9 by James
Tappin <james@xena.uklinux.net>
1 January 2010