1 /* faked 940 code just uses local copy of ym2612 */
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"
22 YM2612 *ym2612_940 = &ym2612;
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_;
29 unsigned char *mp3_mem = 0;
31 #define MP3_SIZE_MAX (0x1000000 - 4*640*480)
33 /***********************************************************/
36 int YM2612Write_940(unsigned int a, unsigned int v)
40 return 0; // cause the engine to do updates once per frame only
43 UINT8 YM2612Read_940(void)
49 int YM2612PicoTick_940(int n)
57 void YM2612PicoStateLoad_940(void)
61 YM2612PicoStateLoad_();
63 for(i = 0; i < 0x100; i++) {
65 YM2612Write_(1, ym2612.REGS[i]);
67 for(i = 0; i < 0x100; i++) {
69 YM2612Write_(3, ym2612.REGS[i|0x100]);
74 void sharedmem_init(void)
76 mp3_mem = malloc(MP3_SIZE_MAX);
79 void sharedmem_deinit(void)
84 void YM2612Init_940(int baseclock, int rate)
86 YM2612Init_(baseclock, rate);
90 void YM2612ResetChip_940(void)
97 static void local_decode(void)
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
105 if (bytesLeft <= 0) return; // EOF, nothing to do
107 offset = MP3FindSyncWord(readPtr, bytesLeft);
109 shared_ctl->mp3_offs = shared_ctl->mp3_len;
115 err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
116 shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
118 if (err == ERR_MP3_INDATA_UNDERFLOW) {
119 shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
121 } else if (err <= -6 && err >= -12) {
122 // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
123 // just try to skip the offending frame..
126 shared_ctl->mp3_errors++;
127 shared_ctl->mp3_lasterr = err;
129 shared_ctl->mp3_offs = readPtr - mp3_mem;
136 static FILE *loaded_mp3 = 0;
138 int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
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;
146 YM2612UpdateOne_(buffer, length, stereo); // really writes to mix_buffer
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;
152 /* mix data from previous go */
153 if (cdda_on && mp3_samples_ready >= length)
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);
158 mp3_buffer_offs += length;
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);
168 mp3_samples_ready -= length;
170 mix_samples(buffer, ym_buffer, 0, length, stereo);
173 // make sure we will have enough mp3 samples next frame
174 if (cdda_on && mp3_samples_ready < length)
176 shared_ctl->mp3_buffsel ^= 1;
178 mp3_samples_ready += 1152;
181 return YM2612UpdateOne_(buffer, length, stereo, is_buf_empty);
186 void mp3_update(int *buffer, int length, int stereo)
192 /***********************************************************/
194 void mp3_start_play(FILE *f, int pos) // pos is 0-1023
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);
211 byte_offs = (shared_ctl->mp3_len << 6) >> 10;
215 printf("mp3 pos1024: %i, byte_offs %i/%i\n", pos, byte_offs, shared_ctl->mp3_len);
217 shared_ctl->mp3_offs = byte_offs;
221 int mp3_get_offset(void)