linux/940ctl_ym2612.c

   1 /* faked 940 code just uses local copy of ym2612 */
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <sys/mman.h>
   7 #include <sys/ioctl.h>
   8 #include <fcntl.h>
   9 #include <errno.h>
  10
  11 #include "../../pico/sound/ym2612.h"
  12 #include "../gp2x/gp2x.h"
  13 #include "../gp2x/emu.h"
  14 #include "../gp2x/menu.h"
  15 #include "../gp2x/code940/940shared.h"
  16 #include "../common/helix/pub/mp3dec.h"
  17 #include "../../pico/pico_int.h"
  18
  19
  20 // static _940_data_t  shared_data_;
  21 static _940_ctl_t   shared_ctl_;
  22 // static _940_data_t *shared_data = &shared_data_;
  23 _940_ctl_t  *shared_ctl = &shared_ctl_;
  24
  25 unsigned char *mp3_mem = 0;
  26
  27 #define MP3_SIZE_MAX (0x1000000 - 4*640*480)
  28
  29 /***********************************************************/
  30
  31
  32 int YM2612Write_940(unsigned int a, unsigned int v, int scanline)
  33 {
  34         YM2612Write_(a, v);
  35
  36         return 0; // cause the engine to do updates once per frame only
  37 }
  38
  39
  40 void YM2612PicoStateLoad_940(void)
  41 {
  42         int i;
  43
  44         YM2612PicoStateLoad_();
  45
  46         for(i = 0; i < 0x100; i++) {
  47                 YM2612Write_(0, i);
  48                 YM2612Write_(1, ym2612.REGS[i]);
  49         }
  50         for(i = 0; i < 0x100; i++) {
  51                 YM2612Write_(2, i);
  52                 YM2612Write_(3, ym2612.REGS[i|0x100]);
  53         }
  54 }
  55
  56 void YM2612PicoStateSave2_940(int tat, int tbt)
  57 {
  58         YM2612PicoStateSave2(tat, tbt);
  59 }
  60
  61 int YM2612PicoStateLoad2_940(int *tat, int *tbt)
  62 {
  63         return YM2612PicoStateLoad2(tat, tbt);
  64 }
  65
  66
  67 void sharedmem_init(void)
  68 {
  69         mp3_mem = malloc(MP3_SIZE_MAX);
  70 }
  71
  72 void sharedmem_deinit(void)
  73 {
  74         free(mp3_mem);
  75 }
  76
  77 void YM2612Init_940(int baseclock, int rate)
  78 {
  79         YM2612Init_(baseclock, rate);
  80 }
  81
  82
  83 void YM2612ResetChip_940(void)
  84 {
  85         YM2612ResetChip_();
  86 }
  87
  88
  89 #if 0
  90 static void local_decode(void)
  91 {
  92         int mp3_offs = shared_ctl->mp3_offs;
  93         unsigned char *readPtr = mp3_mem + mp3_offs;
  94         int bytesLeft = shared_ctl->mp3_len - mp3_offs;
  95         int offset; // frame offset from readPtr
  96         int err = 0;
  97
  98         if (bytesLeft <= 0) return; // EOF, nothing to do
  99
 100         offset = MP3FindSyncWord(readPtr, bytesLeft);
 101         if (offset < 0) {
 102                 shared_ctl->mp3_offs = shared_ctl->mp3_len;
 103                 return; // EOF
 104         }
 105         readPtr += offset;
 106         bytesLeft -= offset;
 107
 108         err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
 109                         shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
 110         if (err) {
 111                 if (err == ERR_MP3_INDATA_UNDERFLOW) {
 112                         shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
 113                         return;
 114                 } else if (err <= -6 && err >= -12) {
 115                         // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
 116                         // just try to skip the offending frame..
 117                         readPtr++;
 118                 }
 119                 shared_ctl->mp3_errors++;
 120                 shared_ctl->mp3_lasterr = err;
 121         }
 122         shared_ctl->mp3_offs = readPtr - mp3_mem;
 123 }
 124 #endif
 125
 126
 127
 128
 129 static FILE *loaded_mp3 = 0;
 130
 131 int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
 132 {
 133 #if 0
 134         int cdda_on, *ym_buffer = mix_buffer;
 135         static int mp3_samples_ready = 0, mp3_buffer_offs = 0;
 136         static int mp3_play_bufsel = 1;
 137
 138
 139         YM2612UpdateOne_(buffer, length, stereo); // really writes to mix_buffer
 140
 141         // emulatind MCD, not data track, CDC is reading, playback was started, track not ended
 142         cdda_on = (PicoMCD & 1) && !(Pico_mcd->s68k_regs[0x36] & 1) && (Pico_mcd->scd.Status_CDC & 1)
 143                         && loaded_mp3 && shared_ctl->mp3_offs < shared_ctl->mp3_len;
 144
 145         /* mix data from previous go */
 146         if (cdda_on && mp3_samples_ready >= length)
 147         {
 148                 if (1152 - mp3_buffer_offs >= length) {
 149                         mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, length, stereo);
 150
 151                         mp3_buffer_offs += length;
 152                 } else {
 153                         // collect from both buffers..
 154                         int left = 1152 - mp3_buffer_offs;
 155                         mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, left, stereo);
 156                         mp3_play_bufsel ^= 1;
 157                         mp3_buffer_offs = length - left;
 158                         mix_samples(buffer + left * 2, ym_buffer + left * 2,
 159                                 shared_data->mp3_buffer[mp3_play_bufsel], mp3_buffer_offs, stereo);
 160                 }
 161                 mp3_samples_ready -= length;
 162         } else {
 163                 mix_samples(buffer, ym_buffer, 0, length, stereo);
 164         }
 165
 166         // make sure we will have enough mp3 samples next frame
 167         if (cdda_on && mp3_samples_ready < length)
 168         {
 169                 shared_ctl->mp3_buffsel ^= 1;
 170                 local_decode();
 171                 mp3_samples_ready += 1152;
 172         }
 173 #else
 174         return YM2612UpdateOne_(buffer, length, stereo, is_buf_empty);
 175 #endif
 176 }
 177
 178
 179 void mp3_update(int *buffer, int length, int stereo)
 180 {
 181         // nothing..
 182 }
 183
 184
 185 /***********************************************************/
 186
 187 void mp3_start_play(FILE *f, int pos) // pos is 0-1023
 188 {
 189         int byte_offs = 0;
 190
 191         if (loaded_mp3 != f)
 192         {
 193                 printf("loading mp3... "); fflush(stdout);
 194                 fseek(f, 0, SEEK_SET);
 195                 fread(mp3_mem, 1, MP3_SIZE_MAX, f);
 196                 if (feof(f)) printf("done.\n");
 197                 else printf("done. mp3 too large, not all data loaded.\n");
 198                 shared_ctl->mp3_len = ftell(f);
 199                 loaded_mp3 = f;
 200         }
 201
 202         // seek..
 203         if (pos) {
 204                 byte_offs  = (shared_ctl->mp3_len << 6) >> 10;
 205                 byte_offs *= pos;
 206                 byte_offs >>= 6;
 207         }
 208         printf("mp3 pos1024: %i, byte_offs %i/%i\n", pos, byte_offs, shared_ctl->mp3_len);
 209
 210         shared_ctl->mp3_offs = byte_offs;
 211 }
 212
 213