glenda.party
term% ls -F
term% pwd
$home/manuals/9front/3/audio
term% cat index.txt
AUDIO(3)                   Library Functions Manual                   AUDIO(3)



NAME
       audio - audio device

SYNOPSIS
       bind -a #A /dev
       /dev/audio
       /dev/audioctl
       /dev/audiostat
       /dev/volume

DESCRIPTION
       The  audio  device  serves  a one-level directory, giving access to the
       stereo audio ports.  Audio is the data file, which can be  written  for
       audio  playback.  Audio data is a sequence of stereo samples, left sam‐
       ple first.  Each sample is a 16 bit little-endian two's complement  in‐
       teger; the default sampling rate is 44.1 kHz.

       The length of the audio file as returned by stat(2) represents the num‐
       ber of bytes buffered for output.

       Audioctl is driver specific control file and left undocumented here.

       Audiostat is a read only status file. The first line has a length of 32
       bytes including the newline and starts with the string bufsize followed
       by the preferred write unit (in bytes) and the string buffered followed
       by  the  number  of  bytes currently queued for output. The numbers are
       decimal and right-padded with spaces to fit.  After this fixed  header,
       the contents of the file is driver specific.

       Volume is the control file associated with the audio port.  Each source
       has an associated stereo volume control, ranging from 0 (quiet) to  100
       (loud).  In addition, there are controls for the sampling rate, latency
       control and for any tone controls.  Reads return lines of the form

              source left right

       or

              source value

       Valid sources depend on the particular audio device, though all devices
       have  an audio stereo source, which controls the output volume from the
       D/A converter.  Values for speed set the sampling frequency of the  au‐
       dio device and delay limits the audio data output buffering to a number
       of samples.

       Writes accept the same format except that for stereo sources  left  and
       right  can  be  abbreviated to a single value if both should be set the
       same.

SOURCE
       /sys/src/9/port/devaudio.c

SEE ALSO
       nusb(4)



                                                                      AUDIO(3)