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 sup‐
ported 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.
Help: show syntax.
Print current version.
List all soundcards and digital audio devices
List all PCMs defined
Select PCM by name
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.
The number of channels. The default is one channel. Valid val‐
ues are 1 through 32.
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_SUB‐
FRAME_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
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.
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.
Interrupt after # seconds. A value of zero means infinity. The
default is zero, so if this option is omitted then the
record/playback process will run until it is killed. Either
'-d' or '-s' option is available exclusively.
Interrupt after tranmission of # PCM frames. A value of zero
means infinity. The default is zero, so if this options is
omitted then the record/playback process will run until it is
killed. Either '-d' or '-s' option is available exclusively.
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.
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
Distance between interrupts is # microseconds. If no period
time and no period size is given then a quarter of the buffer
time is set.
Buffer duration is # microseconds If no buffer time and no buf‐
fer size is given then the maximal allowed buffer time but not
more than 500ms is set.
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 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.
Min available space for wakeup is # microseconds
Delay for automatic PCM start is # microseconds (relative to
buffer size if <= 0)
Delay for automatic PCM stop is # microseconds from xrun
Show PCM structure and setup. This option is accumulative. The
VU meter is displayed when this is given twice or three times.
Specifies the VU-meter type, either stereo or mono. The stereo
VU-meter is available only for 2-channel stereo samples with in‐
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 typ‐
-C Record. This is the default if the program is invoked by typing
Allow interactive operation via stdin. Currently only pause/re‐
sume via space or enter key is implemented.
Give the channel map to override or follow. Pass channel posi‐
tion strings like FL, FR, etc.
If a device supports the override of the channel map, aplay
tries to pass the given channel map. If it doesn't support the
channel map override but still it provides the channel map in‐
formation, aplay tries to rearrange the channel order in the
buffer to match with the returned channel map from the device.
Disable automatic rate resample.
Disable automatic channel conversions.
Disable automatic format conversions.
Disable software volume control (softvol).
Test ring buffer position.
Test coefficient for ring buffer position; default is 8. Ex‐
pression for validation is: coef * (buffer_size / 2). Minimum
value is 1.
Do not wait for the ring buffer ‐ eats the whole CPU.
While recording, when the output file has been accumulating
sound for this long, close it and open a new output file. De‐
fault is the maximum size supported by the file format: 2 GiB
for WAV files. This option has no effect if --separate-chan‐
nels is specified.
aplay writes its process ID here, so other programs can send
signals to it.
When recording, interpret %-codes in the file name parameter us‐
ing 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 addi‐
tion, %v is the file number, starting at 1. When this option is
specified, intermediate directories for the output file are cre‐
ated automatically. This option has no effect if --sepa‐
rate-channels is specified.
Dump hw_params of the device preconfigured status to stderr. The
dump lists capabilities of the selected device such as supported
formats, sampling rates, numbers of channels, period and buffer
bytes/sizes/times. For raw device hw:X this option basically
lists hardware capabilities of the soundcard.
Disables recovery attempts when errors (e.g. xrun) are encoun‐
tered; the aplay process instead aborts immediately.
When recording, SIGINT, SIGTERM and SIGABRT will close the output file
and exit. SIGUSR1 will close the output file, open a new one, and con‐
tinue recording. However, SIGUSR1 does not work with --separate-chan‐
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, us‐
ing the PCM "copy" (which might be defined in the user's
.asoundrc file as:
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 sec‐
onds. 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/lis‐
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.