aplay.1

ALSA驱动的一些调试测试工具

.TH APLAY 1 "2 August 2001"
.SH NAME
arecord, aplay \- command-line sound recorder and player for ALSA 
soundcard driver
.SH SYNOPSIS
\fBarecord\fP [\fIflags\fP] [filename]
.br
\fBaplay\fP [\fIflags\fP] [filename [filename]] ...

.SH DESCRIPTION
\fBarecord\fP 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.

\fBaplay\fP 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 \fBaplay\fP utility accepts multiple filenames.

.SH OPTIONS
.TP
\fI\-h, \-\-help\fP
Help: show syntax.
.TP
\fI\-\-version\fP
Print current version.
.TP
\fI\-l, \-\-list\-devices\fP
List all soundcards and digital audio devices
.TP
\fI\-L, \-\-list\-pcms\fP
List all PCMs defined
.TP
\fI\-D, \-\-device=NAME\fP
Select PCM by name
.TP
\fI\-q \-\-quiet\fP
Quiet mode. Suppress messages (not sound :))
.TP
\fI\-t, \-\-file\-type TYPE\fP
File type (voc, wav, raw or au).
If this parameter is omitted the WAVE format is used.
.TP
\fI\-c, \-\-channels=#\fP
The number of channels.
The default is one channel.
.TP
\fI\-f \-\-format=FORMAT\fP
Sample format
.br
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
.br
Some of these may not be available on selected hardware
.br
There are also two format shortcuts available:
.nf
\-f cd (16 bit little endian, 44100, stereo [\-f S16_LE \-c2 \-r44100]
\-f dat (16 bit little endian, 48000, stereo) [\-f S16_LE \-c2 \-r48000]
.fi
If no format is given U8 is used.
.TP
\fI\-r, \-\-rate=#<Hz>\fP
Sampling rate in Hertz. The default rate is 8000 Hertz.
.TP
\fI\-d, \-\-duration=#\fP
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.
.TP
\fI\-s, \-\-sleep\-min=#\fP
Min ticks to sleep. The default is not to sleep.
.TP
\fI\-M, \-\-mmap\fP            
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.
.TP
\fI\-N, \-\-nonblock\fP          
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.
.TP
\fI\-F, \-\-period\-time=#\fP     
Distance between interrupts is # microseconds.
If no period time and no period size is given then a quarter of the buffer time is set.
.TP
\fI\-B, \-\-buffer\-time=#\fP     
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.
.TP
\fI\-\-period\-size=#\fP     
Distance between interrupts is # frames
If no period size and no period time is given then a quarter of the buffer size is set.
.TP
\fI\-\-buffer\-size=#\fP     
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.
.TP
\fI\-A, \-\-avail\-min=#\fP       
Min available space for wakeup is # microseconds
.TP
\fI\-R, \-\-start\-delay=#\fP     
Delay for automatic PCM start is # microseconds 
(relative to buffer size if <= 0)
.TP
\fI\-T, \-\-stop\-delay=#\fP      
Delay for automatic PCM stop is # microseconds from xrun
.TP
\fI\-v, \-\-verbose\fP           
Show PCM structure and setup.
This option is accumulative.  The VU meter is displayed when this
is given twice or three times.
.TP
\fI\-V, \-\-vumeter=TYPE\fP
Specifies the VU-meter type, either \fIstereo\fP or \fImono\fP.
The stereo VU-meter is available only for 2-channel stereo samples
with interleaved format.
.TP
\fI\-I, \-\-separate\-channels\fP 
One file for each channel

.SS
Example:

.TP
\fBaplay \-c 1 \-t raw \-r 22050 \-f mu_law foobar\fR
will play the raw file "foobar" as a
22050-Hz, mono, 8-bit, Mu-Law .au file. 

.TP
\fBarecord \-d 10 \-f cd \-t wav \-D copy foobar.wav\fP
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:
.nf
pcm.copy {
  type plug
  slave {
    pcm hw
  }
  route_policy copy
}
.fi

.SH SEE ALSO
\fB
alsamixer(1),
amixer(1)
\fP

.SH BUGS 
Note that .aiff files are not currently supported.

.SH AUTHOR
\fBarecord\fP and \fBaplay\fP are by Jaroslav Kysela <[e-mail]>
This document is by Paul Winkler <[e-mail]>.
Updated for Alsa 0.9 by James Tappin <[e-mail]>