Header

All fields are 32-bits (so 4 octets) unsigned big-endian integers.

magic

Always equal to 0x2E736E64 (".snd")

header size

number of octets the header contains; 24 if no further info was added

data size

number of octets the data contains; 0 or 0xFFFFFFFF for undefined

encoding

refer to codecs section

sample rate

number of samples per seconds (aka Hz). Common ones are 8000, 11025, 16000, 22050, 32000, 44100, and 48000 Hz.

channels

Number of interleaved channels. 1 for mono, 2 for stereo, ...

You may append information after the header in multiple of 8 octets that is terminated and filled with NULL octets. Pure ASCII is the strongly suggested usage but it seen as implementation defined.

Codecs

01

8-bit G.711 µ-law

02

unsigned 8-bit linear PCM

03

16-bit linear PCM

04

24-bit linear PCM

05

32-bit linear PCM

06

32-bit IEEE floating point

07

64-bit IEEE floating point

23

4-bit CCITT G.721 ADPCM

25

CCITT G.723 3-bit ADPCM

27

8-bit G.711 A-law

Note: Linear PCM data is signed and zero-centered.