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
44 void YM2612PicoStateLoad_940(void)
48 YM2612PicoStateLoad_();
50 for(i = 0; i < 0x100; i++) {
52 YM2612Write_(1, ym2612.REGS[i]);
54 for(i = 0; i < 0x100; i++) {
56 YM2612Write_(3, ym2612.REGS[i|0x100]);
61 void sharedmem_init(void)
63 mp3_mem = malloc(MP3_SIZE_MAX);
66 void sharedmem_deinit(void)
71 void YM2612Init_940(int baseclock, int rate)
73 YM2612Init_(baseclock, rate);
77 void YM2612ResetChip_940(void)
84 static void local_decode(void)
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
92 if (bytesLeft <= 0) return; // EOF, nothing to do
94 offset = MP3FindSyncWord(readPtr, bytesLeft);
96 shared_ctl->mp3_offs = shared_ctl->mp3_len;
102 err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
103 shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
105 if (err == ERR_MP3_INDATA_UNDERFLOW) {
106 shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
108 } else if (err <= -6 && err >= -12) {
109 // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
110 // just try to skip the offending frame..
113 shared_ctl->mp3_errors++;
114 shared_ctl->mp3_lasterr = err;
116 shared_ctl->mp3_offs = readPtr - mp3_mem;
123 static FILE *loaded_mp3 = 0;
125 int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
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;
133 YM2612UpdateOne_(buffer, length, stereo); // really writes to mix_buffer
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;
139 /* mix data from previous go */
140 if (cdda_on && mp3_samples_ready >= length)
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);
145 mp3_buffer_offs += length;
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);
155 mp3_samples_ready -= length;
157 mix_samples(buffer, ym_buffer, 0, length, stereo);
160 // make sure we will have enough mp3 samples next frame
161 if (cdda_on && mp3_samples_ready < length)
163 shared_ctl->mp3_buffsel ^= 1;
165 mp3_samples_ready += 1152;
168 return YM2612UpdateOne_(buffer, length, stereo, is_buf_empty);
173 void mp3_update(int *buffer, int length, int stereo)
179 /***********************************************************/
181 void mp3_start_play(FILE *f, int pos) // pos is 0-1023
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);
198 byte_offs = (shared_ctl->mp3_len << 6) >> 10;
202 printf("mp3 pos1024: %i, byte_offs %i/%i\n", pos, byte_offs, shared_ctl->mp3_len);
204 shared_ctl->mp3_offs = byte_offs;
208 int mp3_get_offset(void)