Ticket #1399: myth.diff

libs/libmythtv/vbitext/cc.cpp

@@ -58 +58 @@
 }
 
 
-static int decodebit(unsigned char *data, int threshold)
+static int decodebit(unsigned char *data, int threshold, int scale1)
 {
     int i, sum = 0;
-    for (i = 0; i < 23; i++)
+    for (i = 0; i < scale1; i++)
         sum += data[i];
-    return (sum > threshold * 23);
+    return (sum > threshold * scale1);
 }
 
 
-static int decode(unsigned char *vbiline)
+static int decode(unsigned char *vbiline, int scale0, int scale1)
 {
     int max[7], min[7], val[7], i, clk, tmp, sample, packedbits = 0;
 
@@ -107 +107 @@
 
     for (i = min[6]; vbiline[i] < sample; i++);
 
-    tmp = i + 57;
+    tmp = i + scale0;
     for (i = 0; i < 16; i++)
-        if (decodebit(&vbiline[tmp + i * 57], sample))
+        if (decodebit(&vbiline[tmp + i * scale0], sample, scale1))
             packedbits |= 1 << i;
     return packedbits & parityok(packedbits);
 }
@@ -236 +236 @@
     int sl     = cc->start_line;
     int l21_f1 = spl * (21 - sl);
     int l21_f2 = spl * (cc->line_count + 21 - sl);
-    cc->code1 = decode((unsigned char *)(cc->buffer + l21_f1));
-    cc->code2 = decode((unsigned char *)(cc->buffer + l21_f2));
+    cc->code1 = decode((unsigned char *)(cc->buffer + l21_f1), cc->scale0, cc->scale1);
+    cc->code2 = decode((unsigned char *)(cc->buffer + l21_f2), cc->scale0, cc->scale1);
 }

libs/libmythtv/vbitext/cc.h

@@ -16 +16 @@
     int samples_per_line;
     int start_line;
     int line_count;
+    int scale0, scale1;
 };
 
 int cc_decode(unsigned char *vbiline);

libs/libmythtv/NuppelVideoRecorder.cpp

@@ -2600 +2600 @@
         ntsc_cc->samples_per_line = vfmt.samples_per_line;
         ntsc_cc->start_line       = vfmt.start[0];
         ntsc_cc->line_count       = vfmt.count[0];
+        ntsc_cc->scale0 = (vfmt.sampling_rate + 503488/2) / 503488;
+        ntsc_cc->scale1 = (ntsc_cc->scale0*2+3)/5; /* 40% */
         ptr_end = ntsc_cc->buffer + sz;
         if (sz > CC_VBIBUFSIZE)
         {