workbench/devs/diskimage/include/libraries/mpega.h

   1 /*------------------------------------------------------------------------------
   2
   3     File    :   MPEGA.h
   4
   5     Author  :   Stéphane TAVENARD
   6
   7     $VER:   MPEGA.h  2.0  (21/06/1998)
   8
   9     (C) Copyright 1997-1998 Stéphane TAVENARD
  10         All Rights Reserved
  11
  12     #Rev|   Date   |                      Comment
  13     ----|----------|--------------------------------------------------------
  14     0   |25/10/1997| Initial revision                                     ST
  15     1   |21/06/1998| Added MPEGA_scale                                    ST
  16
  17     ------------------------------------------------------------------------
  18
  19     MPEGA decoder library definitions
  20
  21 ------------------------------------------------------------------------------*/
  22
  23 #ifndef LIBRARIES_MPEGA_H
  24 #define LIBRARIES_MPEGA_H
  25
  26 #define MPEGA_VERSION 2 /* #1 */
  27
  28 #ifndef EXEC_TYPES_H
  29 #include <exec/types.h>
  30 #endif
  31
  32 #ifndef UTILITY_HOOKS_H
  33 #include <utility/hooks.h>
  34 #endif
  35
  36 /* Controls for decoding */
  37
  38 /* Qualities */
  39 #define MPEGA_QUALITY_LOW    0
  40 #define MPEGA_QUALITY_MEDIUM 1
  41 #define MPEGA_QUALITY_HIGH   2
  42
  43 /*
  44    Bitstream Hook function is called like (SAS/C syntax):
  45
  46
  47    ULONG __saveds __asm HookFunc( register __a0 struct Hook  *hook,
  48                                   register __a2 APTR          handle,
  49                                   register __a1 MPEGA_ACCESS *access );
  50
  51    MPEGA_ACCESS struct specify bitstream access function & parameters
  52
  53    access->func == MPEGA_BSFUNC_OPEN
  54       open the bitstream
  55       access->data.open.buffer_size is the i/o block size your read function can use
  56       access->data.open.stream_size is the total size of the current stream
  57                                     (in bytes, set it to 0 if unknown)
  58       return your file handle (or NULL if failed)
  59    access->func == MPEGA_BSFUNC_CLOSE
  60       close the bitstream
  61       return 0 if ok
  62    access->func == MPEGA_BSFUNC_READ
  63       read bytes from bitstream.
  64       access->data.read.buffer is the destination buffer.
  65       access->data.read.num_bytes is the number of bytes requested for read.
  66       return # of bytes read or 0 if EOF.
  67    access->func == MPEGA_BSFUNC_SEEK
  68       seek into the bitstream
  69       access->data.seek.abs_byte_seek_pos is the absolute byte position to reach.
  70       return 0 if ok
  71 */
  72
  73 #define MPEGA_BSFUNC_OPEN  0
  74 #define MPEGA_BSFUNC_CLOSE 1
  75 #define MPEGA_BSFUNC_READ  2
  76 #define MPEGA_BSFUNC_SEEK  3
  77
  78 typedef struct {
  79
  80    LONG  func;           /* MPEGA_BSFUNC_xxx */
  81    union {
  82       struct {
  83          char *stream_name; /* in */
  84          LONG buffer_size;  /* in */
  85          LONG stream_size;  /* out */
  86       } open;
  87       struct {
  88          void *buffer;      /* in/out */
  89          LONG num_bytes;    /* in */
  90       } read;
  91       struct {
  92          LONG abs_byte_seek_pos; /* out */
  93       } seek;
  94    } data;
  95
  96 } MPEGA_ACCESS;
  97
  98 /* Decoding output settings */
  99
 100 typedef struct {
 101    WORD freq_div;    /* 1, 2 or 4 */
 102    WORD quality;     /* 0 (low) .. 2 (high) */
 103    LONG freq_max;    /* for automatic freq_div (if mono_freq_div == 0) */
 104 } MPEGA_OUTPUT;
 105
 106 /* Decoding layer settings */
 107 typedef struct {
 108    WORD force_mono;        /* 1 to decode stereo stream in mono, 0 otherwise */
 109    MPEGA_OUTPUT mono;      /* mono settings */
 110    MPEGA_OUTPUT stereo;    /* stereo settings */
 111 } MPEGA_LAYER;
 112
 113 /* Full control structure of MPEG Audio decoding */
 114 typedef struct {
 115    struct Hook *bs_access;    /* NULL for default access (file I/O) or give your own bitstream access */
 116    MPEGA_LAYER layer_1_2;     /* Layer I & II settings */
 117    MPEGA_LAYER layer_3;       /* Layer III settings */
 118    WORD check_mpeg;           /* 1 to check for mpeg audio validity at start of stream, 0 otherwise */
 119    LONG stream_buffer_size;   /* size of bitstream buffer in bytes (0 -> default size) */
 120                               /* NOTE: stream_buffer_size must be multiple of 4 bytes */
 121 } MPEGA_CTRL;
 122
 123 /* MPEG Audio modes */
 124
 125 #define MPEGA_MODE_STEREO   0
 126 #define MPEGA_MODE_J_STEREO 1
 127 #define MPEGA_MODE_DUAL     2
 128 #define MPEGA_MODE_MONO     3
 129
 130 typedef struct {
 131    /* Public data (read only) */
 132    /* Stream info */
 133    WORD  norm;          /* 1 or 2 */
 134    WORD  layer;         /* 1..3 */
 135    WORD  mode;          /* 0..3  (MPEGA_MODE_xxx) */
 136    WORD  bitrate;       /* in kbps */
 137    LONG  frequency;     /* in Hz */
 138    WORD  channels;      /* 1 or 2 */
 139    ULONG ms_duration;   /* stream duration in ms */
 140    WORD  private_bit;   /* 0 or 1 */
 141    WORD  copyright;     /* 0 or 1 */
 142    WORD  original;      /* 0 or 1 */
 143    /* Decoding info according to MPEG control */
 144    WORD  dec_channels;  /* decoded channels 1 or 2 */
 145    WORD  dec_quality;   /* decoding quality 0..2 */
 146    LONG  dec_frequency; /* decoding frequency in Hz */
 147
 148    /* Private data */
 149    void  *handle;
 150 } MPEGA_STREAM;
 151
 152 #define MPEGA_MAX_CHANNELS 2    // Max channels
 153 #define MPEGA_PCM_SIZE     1152 // Max samples per frame
 154
 155 /* Error codes */
 156
 157 #define MPEGA_ERR_NONE     0
 158 #define MPEGA_ERR_BASE     0
 159 #define MPEGA_ERR_EOF      (MPEGA_ERR_BASE-1)
 160 #define MPEGA_ERR_BADFRAME (MPEGA_ERR_BASE-2)
 161 #define MPEGA_ERR_MEM      (MPEGA_ERR_BASE-3)
 162 #define MPEGA_ERR_NO_SYNC  (MPEGA_ERR_BASE-4)
 163 #define MPEGA_ERR_BADVALUE (MPEGA_ERR_BASE-5) /* #1 */
 164
 165 #endif /* LIBRARIES_MPEGA_H */