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 "../common/helix/pub/mp3dec.h"
  17 #include "../../Pico/PicoInt.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
  57 void sharedmem_init(void)
  58 {
  59         mp3_mem = malloc(MP3_SIZE_MAX);
  60 }
  61
  62 void sharedmem_deinit(void)
  63 {
  64         free(mp3_mem);
  65 }
  66
  67 void YM2612Init_940(int baseclock, int rate)
  68 {
  69         YM2612Init_(baseclock, rate);
  70 }
  71
  72
  73 void YM2612ResetChip_940(void)
  74 {
  75         YM2612ResetChip_();
  76 }
  77
  78
  79 #if 0
  80 static void local_decode(void)
  81 {
  82         int mp3_offs = shared_ctl->mp3_offs;
  83         unsigned char *readPtr = mp3_mem + mp3_offs;
  84         int bytesLeft = shared_ctl->mp3_len - mp3_offs;
  85         int offset; // frame offset from readPtr
  86         int err = 0;
  87
  88         if (bytesLeft <= 0) return; // EOF, nothing to do
  89
  90         offset = MP3FindSyncWord(readPtr, bytesLeft);
  91         if (offset < 0) {
  92                 shared_ctl->mp3_offs = shared_ctl->mp3_len;
  93                 return; // EOF
  94         }
  95         readPtr += offset;
  96         bytesLeft -= offset;
  97
  98         err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
  99                         shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
 100         if (err) {
 101                 if (err == ERR_MP3_INDATA_UNDERFLOW) {
 102                         shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
 103                         return;
 104                 } else if (err <= -6 && err >= -12) {
 105                         // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
 106                         // just try to skip the offending frame..
 107                         readPtr++;
 108                 }
 109                 shared_ctl->mp3_errors++;
 110                 shared_ctl->mp3_lasterr = err;
 111         }
 112         shared_ctl->mp3_offs = readPtr - mp3_mem;
 113 }
 114 #endif
 115
 116
 117
 118
 119 static FILE *loaded_mp3 = 0;
 120
 121 int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
 122 {
 123 #if 0
 124         int cdda_on, *ym_buffer = mix_buffer;
 125         static int mp3_samples_ready = 0, mp3_buffer_offs = 0;
 126         static int mp3_play_bufsel = 1;
 127
 128
 129         YM2612UpdateOne_(buffer, length, stereo); // really writes to mix_buffer
 130
 131         // emulatind MCD, not data track, CDC is reading, playback was started, track not ended
 132         cdda_on = (PicoMCD & 1) && !(Pico_mcd->s68k_regs[0x36] & 1) && (Pico_mcd->scd.Status_CDC & 1)
 133                         && loaded_mp3 && shared_ctl->mp3_offs < shared_ctl->mp3_len;
 134
 135         /* mix data from previous go */
 136         if (cdda_on && mp3_samples_ready >= length)
 137         {
 138                 if (1152 - mp3_buffer_offs >= length) {
 139                         mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, length, stereo);
 140
 141                         mp3_buffer_offs += length;
 142                 } else {
 143                         // collect from both buffers..
 144                         int left = 1152 - mp3_buffer_offs;
 145                         mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, left, stereo);
 146                         mp3_play_bufsel ^= 1;
 147                         mp3_buffer_offs = length - left;
 148                         mix_samples(buffer + left * 2, ym_buffer + left * 2,
 149                                 shared_data->mp3_buffer[mp3_play_bufsel], mp3_buffer_offs, stereo);
 150                 }
 151                 mp3_samples_ready -= length;
 152         } else {
 153                 mix_samples(buffer, ym_buffer, 0, length, stereo);
 154         }
 155
 156         // make sure we will have enough mp3 samples next frame
 157         if (cdda_on && mp3_samples_ready < length)
 158         {
 159                 shared_ctl->mp3_buffsel ^= 1;
 160                 local_decode();
 161                 mp3_samples_ready += 1152;
 162         }
 163 #else
 164         return YM2612UpdateOne_(buffer, length, stereo, is_buf_empty);
 165 #endif
 166 }
 167
 168
 169 void mp3_update(int *buffer, int length, int stereo)
 170 {
 171         // nothing..
 172 }
 173
 174
 175 /***********************************************************/
 176
 177 void mp3_start_play(FILE *f, int pos) // pos is 0-1023
 178 {
 179         int byte_offs = 0;
 180
 181         if (loaded_mp3 != f)
 182         {
 183                 printf("loading mp3... "); fflush(stdout);
 184                 fseek(f, 0, SEEK_SET);
 185                 fread(mp3_mem, 1, MP3_SIZE_MAX, f);
 186                 if (feof(f)) printf("done.\n");
 187                 else printf("done. mp3 too large, not all data loaded.\n");
 188                 shared_ctl->mp3_len = ftell(f);
 189                 loaded_mp3 = f;
 190         }
 191
 192         // seek..
 193         if (pos) {
 194                 byte_offs  = (shared_ctl->mp3_len << 6) >> 10;
 195                 byte_offs *= pos;
 196                 byte_offs >>= 6;
 197         }
 198         printf("mp3 pos1024: %i, byte_offs %i/%i\n", pos, byte_offs, shared_ctl->mp3_len);
 199
 200         shared_ctl->mp3_offs = byte_offs;
 201 }
 202
 203