au format

Offset   Length   Contents
  0      4 bytes  ".snd"
  4      4 bytes  <Header size (h)>
  8      4 bytes  <Sample data size (s)>
 12      4 bytes  <Audio file encoding>
 16      4 bytes  <Sample rate>
 20      4 bytes  <Number of channels>
 24  (h-24)bytes  <Comment>
(h)     (s)bytes  <Sample data>


/* Sun Audio File Encoding Tags */
#define SUN_AUDIO_MAGIC			0x2e736e64
#define AUDIO_FILE_ENCODING_MULAW_8     1      /* 8-bit ISDN u-law */
#define AUDIO_FILE_ENCODING_LINEAR_8    2      /* 8-bit linear PCM */
#define AUDIO_FILE_ENCODING_LINEAR_16   3      /* 16-bit linear PCM */
#define AUDIO_FILE_ENCODING_LINEAR_24   4      /* 24-bit linear PCM */
#define AUDIO_FILE_ENCODING_LINEAR_32   5      /* 32-bit linear PCM */
#define AUDIO_FILE_ENCODING_FLOAT       6      /* 32-bit IEEE floating point */
#define AUDIO_FILE_ENCODING_DOUBLE      7      /* 64-bit IEEE floating point */
#define AUDIO_FILE_ENCODING_INDIRECT    8      /* fragmented sampled data
#define AUDIO_FILE_ENCODING_NESTED      9      /* ? */
#define AUDIO_FILE_ENCODING_DSP_CORE   10      /* DSP program */
#define AUDIO_FILE_ENCODING_DSP_DATA_8 11      /* 8-bit fixed-point samples */
#define AUDIO_FILE_ENCODING_DSP_DATA_16 12     /* 16-bit fixed-point samples */
#define AUDIO_FILE_ENCODING_DSP_DATA_24 13     /* 24-bit fixed-point samples */
#define AUDIO_FILE_ENCODING_DSP_DATA_32 14     /* 32-bit fixed-point samples */
#define AUDIO_FILE_ENCODING_15		15	/* ? */
#define AUDIO_FILE_ENCODING_DISPLAY     16     /* non-audio display data */
#define AUDIO_FILE_ENCODING_MULAW_SQUELCH 17   /* ? */
#define AUDIO_FILE_ENCODING_EMPHASIZED 18      /* 16-bit linear with emphasis */
#define AUDIO_FILE_ENCODING_COMPRESSED 19      /* 16-bit linear with compression */
#define AUDIO_FILE_ENCODING_COMPRESSED_EMPHASIZED 20 /* A combination of the two above */
#define AUDIO_FILE_ENCODING_DSP_COMMANDS 21    /*  Music Kit DSP commands */
#define AUDIO_FILE_ENCODING_DSP_COMMANDS_SAMPLES 22 /* ? */
#define AUDIO_FILE_ENCODING_ADPCM_G721  23     /* 4-bit CCITT g.721 ADPCM */
#define AUDIO_FILE_ENCODING_ADPCM_G722  24     /* CCITT g.722 ADPCM */
#define AUDIO_FILE_ENCODING_ADPCM_G723_3 25    /* CCITT g.723 3-bit ADPCM */
#define AUDIO_FILE_ENCODING_ADPCM_G723_5 26    /* CCITT g.723 5-bit ADPCM */
#define AUDIO_FILE_ENCODING_ALAW_8      27     /* 8-bit ISDN A-law */