+static void do_irq(void)
+{
+ if(!(spuStat & STAT_IRQ))
+ {
+ spuStat |= STAT_IRQ;
+ if(irqCallback) irqCallback();
+ }
+}
+
+static int decode_block(int ch)
+{
+ unsigned char *start;
+ unsigned int nSample;
+ int predict_nr,shift_factor,flags,d,s;
+ int fa,s_1,s_2;
+ int ret = 0;
+
+ s_chan[ch].iSBPos=0;
+
+ start=s_chan[ch].pCurr; // set up the current pos
+ if(start == (unsigned char*)-1 || // special "stop" sign
+ (dwPendingChanOff&(1<<ch)))
+ {
+ dwChannelOn&=~(1<<ch); // -> turn everything off
+ dwPendingChanOff&=~(1<<ch);
+ s_chan[ch].bStop=1;
+ s_chan[ch].ADSRX.EnvelopeVol=0;
+ return 0; // -> and done for this channel
+ }
+
+ //////////////////////////////////////////// irq check
+
+ if(spuCtrl&CTRL_IRQ)
+ {
+ if(pSpuIrq == start) // irq address reached?
+ {
+ do_irq(); // -> call main emu
+ ret = 1;
+ }
+ }
+
+ s_1=s_chan[ch].s_1;
+ s_2=s_chan[ch].s_2;
+
+ predict_nr=(int)*start;start++;
+ shift_factor=predict_nr&0xf;
+ predict_nr >>= 4;
+ flags=(int)*start;start++;
+
+ // -------------------------------------- //
+
+ for (nSample=0;nSample<28;start++)
+ {
+ d=(int)*start;
+ s=((d&0xf)<<12);
+ if(s&0x8000) s|=0xffff0000;
+
+ fa=(s >> shift_factor);
+ fa=fa + ((s_1 * f[predict_nr][0])>>6) + ((s_2 * f[predict_nr][1])>>6);
+ s_2=s_1;s_1=fa;
+ s=((d & 0xf0) << 8);
+
+ s_chan[ch].SB[nSample++]=fa;
+
+ if(s&0x8000) s|=0xffff0000;
+ fa=(s>>shift_factor);
+ fa=fa + ((s_1 * f[predict_nr][0])>>6) + ((s_2 * f[predict_nr][1])>>6);
+ s_2=s_1;s_1=fa;
+
+ s_chan[ch].SB[nSample++]=fa;
+ }
+
+ //////////////////////////////////////////// flag handler
+
+ if((flags&4) && (!s_chan[ch].bIgnoreLoop))
+ s_chan[ch].pLoop=start-16; // loop adress
+
+ if(flags&1) // 1: stop/loop
+ {
+ if(!(flags&2))
+ dwPendingChanOff|=1<<ch;
+
+ start = s_chan[ch].pLoop;
+ }
+
+ if (start - spuMemC >= 0x80000)
+ start = (unsigned char*)-1;
+
+ s_chan[ch].pCurr=start; // store values for next cycle
+ s_chan[ch].s_1=s_1;
+ s_chan[ch].s_2=s_2;
+
+ return ret;
+}
+
+// do block, but ignore sample data
+static int skip_block(int ch)
+{
+ unsigned char *start = s_chan[ch].pCurr;
+ int flags = start[1];
+ int ret = 0;
+
+ // Tron Bonne hack, probably wrong (could be wrong memory contents..)
+ if(flags & ~7) flags = 0;
+
+ if(start == pSpuIrq)
+ {
+ do_irq();
+ ret = 1;
+ }
+
+ if((flags & 4) && !s_chan[ch].bIgnoreLoop)
+ s_chan[ch].pLoop=start;
+
+ s_chan[ch].pCurr += 16;
+
+ if(flags & 1)
+ s_chan[ch].pCurr = s_chan[ch].pLoop;
+
+ return ret;
+}
+
+#define make_do_samples(name, fmod_code, interp_start, interp1_code, interp2_code, interp_end) \
+static int do_samples_##name(int ch, int ns, int ns_to) \
+{ \
+ int sinc = s_chan[ch].sinc; \
+ int spos = s_chan[ch].spos; \
+ int ret = -1; \
+ int d, fa; \
+ interp_start; \
+ \
+ for (; ns < ns_to; ns++) \
+ { \
+ fmod_code; \
+ \
+ while (spos >= 0x10000) \
+ { \
+ if(s_chan[ch].iSBPos == 28) \
+ { \
+ d = decode_block(ch); \
+ if(d && iSPUIRQWait) \
+ { \
+ ret = ns; \
+ goto out; \
+ } \
+ } \
+ \
+ fa = s_chan[ch].SB[s_chan[ch].iSBPos++]; \
+ interp1_code; \
+ spos -= 0x10000; \
+ } \
+ \
+ interp2_code; \
+ spos += sinc; \
+ } \
+ \
+out: \
+ s_chan[ch].sinc = sinc; \
+ s_chan[ch].spos = spos; \
+ interp_end; \
+ \
+ return ret; \
+}
+
+#define fmod_recv_check \
+ if(s_chan[ch].bFMod==1 && iFMod[ns]) \
+ sinc = FModChangeFrequency(ch,ns)
+
+make_do_samples(default, fmod_recv_check, ,
+ StoreInterpolationVal(ch, fa),
+ ChanBuf[ns] = iGetInterpolationVal(ch), )
+make_do_samples(noint, , fa = s_chan[ch].SB[29], , ChanBuf[ns] = fa, s_chan[ch].SB[29] = fa)
+
+#define simple_interp_store \
+ s_chan[ch].SB[28] = 0; \
+ s_chan[ch].SB[29] = s_chan[ch].SB[30]; \
+ s_chan[ch].SB[30] = s_chan[ch].SB[31]; \
+ s_chan[ch].SB[31] = fa; \
+ s_chan[ch].SB[32] = 1
+
+#define simple_interp_get \
+ if(sinc<0x10000) /* -> upsampling? */ \
+ InterpolateUp(ch); /* --> interpolate up */ \
+ else InterpolateDown(ch); /* --> else down */ \
+ ChanBuf[ns] = s_chan[ch].SB[29]
+
+make_do_samples(simple, , ,
+ simple_interp_store, simple_interp_get, )
+
+static int do_samples_noise(int ch, int ns, int ns_to)
+{
+ s_chan[ch].spos += s_chan[ch].sinc * (ns_to - ns);
+ while (s_chan[ch].spos >= 28*0x10000)
+ {
+ skip_block(ch);
+ s_chan[ch].spos -= 28*0x10000;
+ }
+
+ for (; ns < ns_to; ns++)
+ ChanBuf[ns] = iGetNoiseVal(ch);
+
+ return -1;
+}
+