CDTV CD+G timing fix

diff --git a/cdtv.cpp b/cdtv.cpp
index fab65104b7a24ec54e3ff5ada374d19fae158d80..780041a1311f021a36437ce7a366b6ca5b44898b 100644 (file)
--- a/cdtv.cpp
+++ b/cdtv.cpp
@@ -113,6 +113,8 @@ static void INT2 (void)
 static volatile int cdrom_command_cnt_out, cdrom_command_size_out;
 static uae_u8 cdrom_command_output[16];
 
+// scor = subchannel frame
+// sbcp = subchannel data byte
 static volatile int stch, sten, scor, sbcp;
 static volatile int cmd, enable, xaen, dten;
 
@@ -997,38 +999,36 @@ static void tp_bput (int addr, uae_u8 v)
 
 static uae_u8 subtransferbuf[SUB_CHANNEL_SIZE];
 
-#define SUBCODE_CYCLES (2 * maxhpos)
+#define SUBCODE_CYCLES (460)
 static int subcode_activecnt;
 
-static void subcode_interrupt (uae_u32 v)
+static void subcode_interrupt(uae_u32 v)
 {
+       if (subcodeoffset < -1) {
+               return;
+       }
+       if (scor < 0) {
+               scor = 0;
+               tp_check_interrupts();
+       }
        subcode_activecnt--;
        if (subcode_activecnt > 0) {
-               if (subcode_activecnt > 1)
-                       subcode_activecnt = 1;
-               return;
+               if (sbcp || scor) {
+                       event2_newevent2(SUBCODE_CYCLES, 0, subcode_interrupt);
+                       return;
+               }
        }
-
-       if (subcodeoffset < -1)
-               return;
        if (sbcp && scor == 0) {
                sbcp = 0;
                // CD+G interrupt didn't read data fast enough, just abort until next packet
                return;
        }
-       if (scor < 0) {
-               scor = 0;
-               if (issub ()) {
-                       subcodeoffset = 0;
-               }
-               tp_check_interrupts ();
+       if (subcodeoffset >= 0) {
+               sbcp = 1;
+               tp_check_interrupts();
        }
-       if (subcodeoffset >= SUB_CHANNEL_SIZE)
-               return;
-       sbcp = 1;
-       tp_check_interrupts ();
-       subcode_activecnt++;
-       event2_newevent2 (SUBCODE_CYCLES, 0, subcode_interrupt);
+       subcode_activecnt = 2;
+       event2_newevent2(SUBCODE_CYCLES, 0, subcode_interrupt);
 }
 
 static uae_u8 tp_bget (int addr)
@@ -1055,10 +1055,11 @@ static uae_u8 tp_bget (int addr)
                        tp_a |= (v << 5) & 64;
                        tp_a |= (v << 7) & 128;
                        v = tp_a;
-                       subcodeoffset++;
                        sbcp = 0;
-                       if (subcodeoffset >= SUB_CHANNEL_SIZE)
+                       subcodeoffset++;
+                       if (subcodeoffset >= SUB_CHANNEL_SIZE) {
                                subcodeoffset = -2;
+                       }
                }
                break;
        case 1:
@@ -1220,7 +1221,7 @@ static void CDTV_hsync_handler (void)
        }
 
        static int subchannelcounter;
-       int cntmax = (int)(maxvpos * vblank_hz / 75 - 6);
+       int cntmax = (int)(maxvpos * vblank_hz / 75 - 2);
        if (subchannelcounter > 0)
                subchannelcounter--;
        if (subchannelcounter <= 0) {
@@ -1240,7 +1241,9 @@ static void CDTV_hsync_handler (void)
                                                subcodebufferoffset -= MAX_SUBCODEBUFFER;
                                        sbcp = 0;
                                        scor = 1;
-                                       subcode_activecnt++;
+                                       subcodeoffset = 0;
+                                       subcode_activecnt = 5;
+                                       event2_newevent_x_remove(subcode_interrupt);
                                        event2_newevent2 (SUBCODE_CYCLES, 0, subcode_interrupt);
                                        tp_check_interrupts ();
                                }