Sox
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sox -c 2 -t raw -b 16 - e signed -r 48000 -L /tmp/moise-1677899.wav -c 1 -t raw -b 16 - e signed -r 48000 -L - remix 1
The heart of SoX is a library called libSoX. Those interested in extending SoX or using it in other pro-
grams should refer to the libSoX manual page: libsox(3).
SoX is a command-line audio processing tool, particularly suited to making quick, simple edits and to batch
processing. If you need an interactive, graphical audio editor, use audacity(1).
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The overall SoX processing chain can be summarised as follows:
Input(s) → Combiner → Effects → Output(s)
The following four characteristics are used to describe the format of audio data such that it can be pro-
cessed with SoX:
sample rate
The sample rate in samples per second (‘Hertz’ or ‘Hz’). Digital telephony traditionally uses a
sample rate of 8000 Hz (8 kHz), though these days, 16 and even 32 kHz are becoming more com-
mon. Audio Compact Discs use 44100 Hz (44.1 kHz). Digital Audio Tape and many computer
systems use 48 kHz. Professional audio systems often use 96 kHz.
sample size
The number of bits used to store each sample. Today, 16-bit is commonly used. 8-bit was popular
in the early days of computer audio. 24-bit is used in the professional audio arena. Other sizes are
also used.
data encoding
The way in which each audio sample is represented (or ‘encoded’). Some encodings have variants
with different byte-orderings or bit-orderings. Some compress the audio data so that the stored
audio data takes up less space (i.e. disk space or transmission bandwidth) than the other format
parameters and the number of samples would imply. Commonly-used encoding types include
floating-point, μ-law, ADPCM, signed-integer PCM, MP3, and FLAC.
channels
The number of audio channels contained in the file. One (‘mono’) and two (‘stereo’) are widely
used. ‘Surround sound’ audio typically contains six or more channels.
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