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