audio - Inferno audio file format 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 configured, using read , write or stream (see sys-read (2)).

Each header line corresponds to a command that can be written 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 usually 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).

auplay (1), audio (3)