workbench/classes/datatypes/sound/aiff.h

   1
   2 /*
   3 **      aiff.h
   4 **      stolen from Olaf Barthels' aiff.dt
   5 */
   6
   7 #ifndef AIFF_H
   8 #define AIFF_H
   9
  10 #ifndef EXEC_TYPES_H
  11 #include <exec/types.h>
  12 #endif
  13
  14 typedef struct {
  15         UWORD   exponent;                       // Exponent, bit #15 is sign bit for mantissa
  16         ULONG   mantissa[2];                    // 64 bit mantissa
  17 } extended;
  18
  19 // Audio Interchange Format chunk data
  20
  21 #define ID_AIFF MAKE_ID('A', 'I', 'F', 'F')
  22
  23 #define ID_COMM         MAKE_ID('C', 'O', 'M', 'M')
  24 #define ID_SSND         MAKE_ID('S', 'S', 'N', 'D')
  25
  26 // "COMM" chunk header
  27
  28 typedef struct {
  29         WORD            numChannels;            // Number of channels
  30         ULONG           numSampleFrames;        // Number of sample frames
  31         WORD            sampleSize;             // Number of bits per sample point
  32         extended        sampleRate;             // Replay rate in samples per second
  33 } CommonChunk;
  34
  35 // "SSND" chunk header
  36
  37 typedef struct {
  38         ULONG   offset,                         // Offset to sound data, for block alignment
  39                         blockSize;                      // Size of block data is aligned to
  40 } SampledSoundHeader;
  41
  42 static void ulong2extended( ULONG value, extended *ex )
  43 {
  44         ex->exponent = 31 + 16383;
  45
  46         while( ( value & 0x80000000 ) == 0 )
  47         {
  48                 value <<= 1;
  49
  50                 ex->exponent--;
  51         }
  52
  53         ex->mantissa[0] = value;
  54         ex->mantissa[1] = 0;
  55 }
  56
  57 #endif