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Au file format

The Au file format is a simple audio file format that consists of a header of 6 32-bit words and then the data. The format was introduced by Sun Microsystems.

32 bit wordfielddescription/content
0magic numberthe value 0x2e736e64 (four ASCII characters ".snd")
1data offset the offset to the data in bytes. The minimum valid number is 24 (decimal).
2data sizedata size in bytes. If unknown, the value 0xffffffff should be used.
3encodingData encoding format: 1=8-bit ISDN u-law, 2=8-bit linear PCM [REF-PCM], 3=16-bit linear PCM, 4=24-bit linear PCM, 5=32-bit linear PCM, 6=32-bit IEEE floating point, 7=64-bit IEEE floating point, 23=8-bit ISDN u-law compressed using the UIT-T G.721 ADPCM voice data encoding scheme.
4sample ratethe number of samples/second (e.g., 8000)
5channelsthe number of interleaved channels (e.g., 1 for mono, 2 for stereo)