AUDIO(6) AUDIO(6)
NAME
audio - Inferno audio file format
DESCRIPTION
Inferno audio files accepted by commands such as auplay(1)
have a simple format. The file contains a header consisting
of non-empty lines of text specifying the data format and
characteristics, followed by an empty line, followed by the
audio data in binary form. The data can be copied directly
to a suitable audio device (see audio(3)) correctly config-
ured, using read, write or stream (see sys-read(2)).
Each header line corresponds to a command that can be writ-
ten to the control file audioctl of the audio(3) device.
The first line of the header must be a rate command; other
commands can appear in any order. The commands available
are:
rate n
The data was recorded at n Hz, typically one of 44100,
22050, 11025 or 8000 but other values are legal.
chans n
There are n channels of audio data (eg, 1 for mono and
2 for stereo).
bits n
Each sample is n bits (typically 8 or 16).
enc e
The string e gives the recording format, and will usu-
ally be one of the following: ulaw, alaw, pcm or adpcm.
The audio data is stored with a sample from each channel in
turn (`left' sample first if stereo, regardless of encoding
or data size). Data encoded as pcm is little-endian, 2's
complement if 16-bit, but unsigned if 8 bit. The adpcm
encoding uses 4-bit samples (two mono samples or one stereo
sample per byte, again little-endian).
SEE ALSO
auplay(1), audio(3)
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