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 "../gp2x/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 static _940_ctl_t *shared_ctl = &shared_ctl_;
29 unsigned char *mp3_mem = 0;
31 #define MP3_SIZE_MAX (0x1000000 - 4*640*480)
33 /***********************************************************/
35 #define MAXOUT (+32767)
36 #define MINOUT (-32768)
39 #define Limit(val, max,min) { \
40 if ( val > max ) val = max; \
41 else if ( val < min ) val = min; \
45 int YM2612Write_940(unsigned int a, unsigned int v)
49 return 0; // cause the engine to do updates once per frame only
52 UINT8 YM2612Read_940(void)
58 int YM2612PicoTick_940(int n)
66 void YM2612PicoStateLoad_940(void)
70 YM2612PicoStateLoad_();
72 for(i = 0; i < 0x100; i++) {
74 YM2612Write_(1, ym2612.REGS[i]);
76 for(i = 0; i < 0x100; i++) {
78 YM2612Write_(3, ym2612.REGS[i|0x100]);
83 void YM2612Init_940(int baseclock, int rate)
85 mp3_mem = malloc(MP3_SIZE_MAX);
87 YM2612Init_(baseclock, rate);
91 void YM2612ResetChip_940(void)
98 static void local_decode(void)
100 int mp3_offs = shared_ctl->mp3_offs;
101 unsigned char *readPtr = mp3_mem + mp3_offs;
102 int bytesLeft = shared_ctl->mp3_len - mp3_offs;
103 int offset; // frame offset from readPtr
106 if (bytesLeft <= 0) return; // EOF, nothing to do
108 offset = MP3FindSyncWord(readPtr, bytesLeft);
110 shared_ctl->mp3_offs = shared_ctl->mp3_len;
116 err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,
117 shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);
119 if (err == ERR_MP3_INDATA_UNDERFLOW) {
120 shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
122 } else if (err <= -6 && err >= -12) {
123 // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
124 // just try to skip the offending frame..
127 shared_ctl->mp3_errors++;
128 shared_ctl->mp3_lasterr = err;
130 shared_ctl->mp3_offs = readPtr - mp3_mem;
137 static FILE *loaded_mp3 = 0;
139 int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
142 int cdda_on, *ym_buffer = mix_buffer;
143 static int mp3_samples_ready = 0, mp3_buffer_offs = 0;
144 static int mp3_play_bufsel = 1;
147 YM2612UpdateOne_(buffer, length, stereo); // really writes to mix_buffer
149 // emulatind MCD, not data track, CDC is reading, playback was started, track not ended
150 cdda_on = (PicoMCD & 1) && !(Pico_mcd->s68k_regs[0x36] & 1) && (Pico_mcd->scd.Status_CDC & 1)
151 && loaded_mp3 && shared_ctl->mp3_offs < shared_ctl->mp3_len;
153 /* mix data from previous go */
154 if (cdda_on && mp3_samples_ready >= length)
156 if (1152 - mp3_buffer_offs >= length) {
157 mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, length, stereo);
159 mp3_buffer_offs += length;
161 // collect from both buffers..
162 int left = 1152 - mp3_buffer_offs;
163 mix_samples(buffer, ym_buffer, shared_data->mp3_buffer[mp3_play_bufsel] + mp3_buffer_offs*2, left, stereo);
164 mp3_play_bufsel ^= 1;
165 mp3_buffer_offs = length - left;
166 mix_samples(buffer + left * 2, ym_buffer + left * 2,
167 shared_data->mp3_buffer[mp3_play_bufsel], mp3_buffer_offs, stereo);
169 mp3_samples_ready -= length;
171 mix_samples(buffer, ym_buffer, 0, length, stereo);
174 // make sure we will have enough mp3 samples next frame
175 if (cdda_on && mp3_samples_ready < length)
177 shared_ctl->mp3_buffsel ^= 1;
179 mp3_samples_ready += 1152;
182 return YM2612UpdateOne_(buffer, length, stereo, is_buf_empty);
187 /***********************************************************/
189 void mp3_start_play(FILE *f, int pos) // pos is 0-1023
195 printf("loading mp3... "); fflush(stdout);
196 fseek(f, 0, SEEK_SET);
197 fread(mp3_mem, 1, MP3_SIZE_MAX, f);
198 if (feof(f)) printf("done.\n");
199 else printf("done. mp3 too large, not all data loaded.\n");
200 shared_ctl->mp3_len = ftell(f);
206 byte_offs = (shared_ctl->mp3_len << 6) >> 10;
210 printf("mp3 pos1024: %i, byte_offs %i/%i\n", pos, byte_offs, shared_ctl->mp3_len);
212 shared_ctl->mp3_offs = byte_offs;
216 int mp3_get_offset(void)