audio - digital audio input and output bind -a '#A' /dev

/dev/audio

/dev/audioctl

The audio device serves a one-level directory containing two files, giving access to the host or native audio device in a platform-independent way.

Audio is the data file, which can be read or written to exchange data with the device. Audio data is a sequence of stereo samples, left sample first, each of which is a 16 bit little-endian two's complement integer.

Audioctl is the associated control file, which sets the characteristics of the device. Reads return lines of the form

"source [in out] value"

"source in value out value"

"source [in out] left value right value"

"source in left value right value out left value right value" The qualifiers in , out and left , right are omitted if they are not applicable or if the input/output and/or left/right values are the same. The source is one of audio , aux1 , aux2 , line , mono , mic , rate , chans or bits . If source is one of the ports audio , aux1 , aux2 , line , mono or mic , value represents the volume on a scale of 0 (quiet) to 100 (loud). The default volume is 50 for the audio port and 0 for the remainder. If the source is rate , value represents the rate at which the data was recorded in Hz. The default is 22050. If the source is chans , value is the number of channels of audio data - 2 (the default) for stereo, otherwise mono. If the source is bits , value is one of 4, 8 or 16, the sample size in bits.

[in out] enc format Outputs the recording format on the input and/or output channels. Format is one of ulaw , alaw , pcm , pcm16 or adpcm

loop value Value is 0 or 1 to disable or enable loopback respectively.

Writes control the device with strings of a similar format as that for reads.

"source [in out] value"

"source in value out value"

"source [in out] left value right value"

"source in left value right value out left value right value" Set the corresponding value/volume for the particular source. The same conventions apply as in the read case above. The default value of source is audio .

reset Set all attributes to their default value.

loop value Enable (1) or disable (0) loopback mode.

[in out] enc format Set the recording format on the input and/or output channels to format. Format is one of ulaw , alaw , pcm , adpcm .

[left right] dev input Set the input source of the left and/or right ADCs. Input is one of mic , line , aux1 , loop .

/emu/port/devaudio*.c

/emu/*/devaudio.c

/os/*/devaudio.c

/os/*/devcs4231.c

auplay (1)

audio (6)

The device has not been implemented on every platform that could provide it, particularly hosted implementations.

/os/port/devaudio.c (a driver for the SB16) implements an older interface of broadly similar form, but using volume not audioctl , and supports a subset of the commands described above.

The device is exclusive-use and cannot mix streams from several clients.