arecord

APLAY(1)                    General Commands Manual                   APLAY(1)



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
              record/playback process will run until it is killed.  Either
              '-d' or '-s' option is available exclusively.

       -s, --samples=#
              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.

       -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.

       -i, --interactive
              Allow interactive operation via stdin.  Currently only
              pause/resume via space or enter key is implemented.

       -m, --chmap=ch1,ch2,...
              Give the channel map to override or follow.  Pass channel
              position 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
              information, aplay tries to rearrange the channel order in the
              buffer to match with the returned channel map from the device.

       --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.

       --dump-hw-params
              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.

       --fatal-errors
              Disables recovery attempts when errors (e.g. xrun) are
              encountered; the aplay process instead aborts immediately.


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                        APLAY(1)