platform/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 "../gp2x/helix/pub/mp3dec.h"
  17 #include "../../Pico/PicoInt.h"
  18
  19
  20 static YM2612 ym2612;
  21
  22 YM2612 *ym2612_940 = &ym2612;
  23
  24 // static _940_data_t  shared_data_;
  25 static _940_ctl_t   shared_ctl_;
  26 // static _940_data_t *shared_data = &shared_data_;
  27 _940_ctl_t  *shared_ctl = &shared_ctl_;
  28
  29 unsigned char *mp3_mem = 0;
  30
  31 #define MP3_SIZE_MAX (0x1000000 - 4*640*480)
  32
  33 /***********************************************************/
  34
  35
  36 int YM2612Write_940(unsigned int a, unsigned int v)
  37 {
  38         YM2612Write_(a, v);
  39
  40         return 0; // cause the engine to do updates once per frame only
  41 }
  42
  43 UINT8 YM2612Read_940(void)
  44 {
  45         return YM2612Read_();
  46 }
  47
  48
  49 int YM2612PicoTick_940(int n)
  50 {
  51         YM2612PicoTick_(n);
  52
  53         return 0;
  54 }
  55
  56
  57 void YM2612PicoStateLoad_940(void)
  58 {
  59         int i;
  60
  61         YM2612PicoStateLoad_();
  62
  63         for(i = 0; i < 0x100; i++) {
  64                 YM2612Write_(0, i);
  65                 YM2612Write_(1, ym2612.REGS[i]);
  66         }
  67         for(i = 0; i < 0x100; i++) {
  68                 YM2612Write_(2, i);
  69                 YM2612Write_(3, ym2612.REGS[i|0x100]);
  70         }
  71 }
  72
  73
  74 void sharedmem_init(void)
  75 {
  76         mp3_mem = malloc(MP3_SIZE_MAX);
  77 }
  78
  79 void sharedmem_deinit(void)
  80 {
  81         free(mp3_mem);
  82 }
  83
  84 void YM2612Init_940(int baseclock, int rate)
  85 {
  86         YM2612Init_(baseclock, rate);
  87 }
  88
  89
  90 void YM2612ResetChip_940(void)
  91 {
  92         YM2612ResetChip_();
  93 }
  94
  95
  96 #if 0
  97 static void local_decode(void)
  98 {
  99         int mp3_offs = shared_ctl->mp3_offs;
 100         unsigned char *readPtr = mp3_mem + mp3_offs;
 101         int bytesLeft = shared_ctl->mp3_len - mp3_offs;
 102         int offset; // frame offset from readPtr
 103         int err = 0;
 104
 105         if (bytesLeft <= 0) return; // EOF, nothing to do
 106
 107         offset = MP3FindSyncWord(readPtr, bytesLeft);
 108         if (offset < 0) {
 109                 shared_ctl->mp3_offs = shared_ctl->mp3_len;
 110                 return; // EOF
 111         }
 112         readPtr += offset;
 113         bytesLeft -= offset;
 114
 115         err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
 116                         shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
 117         if (err) {
 118                 if (err == ERR_MP3_INDATA_UNDERFLOW) {
 119                         shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
 120                         return;
 121                 } else if (err <= -6 && err >= -12) {
 122                         // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
 123                         // just try to skip the offending frame..
 124                         readPtr++;
 125                 }
 126                 shared_ctl->mp3_errors++;
 127                 shared_ctl->mp3_lasterr = err;
 128         }
 129         shared_ctl->mp3_offs = readPtr - mp3_mem;
 130 }
 131 #endif
 132
 133
 134
 135
 136 static FILE *loaded_mp3 = 0;
 137
 138 int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
 139 {
 140 #if 0
 141         int cdda_on, *ym_buffer = mix_buffer;
 142         static int mp3_samples_ready = 0, mp3_buffer_offs = 0;
 143         static int mp3_play_bufsel = 1;
 144
 145
 146         YM2612UpdateOne_(buffer, length, stereo); // really writes to mix_buffer
 147
 148         // emulatind MCD, not data track, CDC is reading, playback was started, track not ended
 149         cdda_on = (PicoMCD & 1) && !(Pico_mcd->s68k_regs[0x36] & 1) && (Pico_mcd->scd.Status_CDC & 1)
 150                         && loaded_mp3 && shared_ctl->mp3_offs < shared_ctl->mp3_len;
 151
 152         /* mix data from previous go */
 153         if (cdda_on && mp3_samples_ready >= length)
 154         {
 155                 if (1152 - mp3_buffer_offs >= length) {
 156                         mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, length, stereo);
 157
 158                         mp3_buffer_offs += length;
 159                 } else {
 160                         // collect from both buffers..
 161                         int left = 1152 - mp3_buffer_offs;
 162                         mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, left, stereo);
 163                         mp3_play_bufsel ^= 1;
 164                         mp3_buffer_offs = length - left;
 165                         mix_samples(buffer + left * 2, ym_buffer + left * 2,
 166                                 shared_data->mp3_buffer[mp3_play_bufsel], mp3_buffer_offs, stereo);
 167                 }
 168                 mp3_samples_ready -= length;
 169         } else {
 170                 mix_samples(buffer, ym_buffer, 0, length, stereo);
 171         }
 172
 173         // make sure we will have enough mp3 samples next frame
 174         if (cdda_on && mp3_samples_ready < length)
 175         {
 176                 shared_ctl->mp3_buffsel ^= 1;
 177                 local_decode();
 178                 mp3_samples_ready += 1152;
 179         }
 180 #else
 181         return YM2612UpdateOne_(buffer, length, stereo, is_buf_empty);
 182 #endif
 183 }
 184
 185
 186 void mp3_update(int *buffer, int length, int stereo)
 187 {
 188         // nothing..
 189 }
 190
 191
 192 /***********************************************************/
 193
 194 void mp3_start_play(FILE *f, int pos) // pos is 0-1023
 195 {
 196         int byte_offs = 0;
 197
 198         if (loaded_mp3 != f)
 199         {
 200                 printf("loading mp3... "); fflush(stdout);
 201                 fseek(f, 0, SEEK_SET);
 202                 fread(mp3_mem, 1, MP3_SIZE_MAX, f);
 203                 if (feof(f)) printf("done.\n");
 204                 else printf("done. mp3 too large, not all data loaded.\n");
 205                 shared_ctl->mp3_len = ftell(f);
 206                 loaded_mp3 = f;
 207         }
 208
 209         // seek..
 210         if (pos) {
 211                 byte_offs  = (shared_ctl->mp3_len << 6) >> 10;
 212                 byte_offs *= pos;
 213                 byte_offs >>= 6;
 214         }
 215         printf("mp3 pos1024: %i, byte_offs %i/%i\n", pos, byte_offs, shared_ctl->mp3_len);
 216
 217         shared_ctl->mp3_offs = byte_offs;
 218 }
 219
 220
 221 int mp3_get_offset(void)
 222 {
 223         return 0;
 224 }
 225
 226