fix a rare duplicate control code detection problem. Some DVDs apparently

interleave all captioning codes with 0, 0 (no-ops). These must be ignored
by the detection code.
This fix makes the "Pearl Harbor" captions display correctly.

CVS patchset: 1576
CVS date: 2002/03/17 02:56:37

1 files changed, 14 insertions, 1 deletions

diff --git a/src/libspucc/cc_decoder.c b/src/libspucc/cc_decoder.c
index d902a38fb..118c53e54 100644
--- a/src/libspucc/cc_decoder.c
+++ b/src/libspucc/cc_decoder.c
@@ -20,7 +20,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
  *
- * $Id: cc_decoder.c,v 1.7 2002/03/11 12:31:26 guenter Exp $
+ * $Id: cc_decoder.c,v 1.8 2002/03/17 02:56:37 cvogler Exp $
  *
  * stuff needed to provide closed captioning decoding and display
  *
@@ -1179,6 +1179,19 @@ static void cc_decode_EIA608(cc_decoder_t *this, uint16_t data)
   uint8_t c1 = data & 0x7f;
   uint8_t c2 = (data >> 8) & 0x7f;
 
+  /* Ignore 0 0 encoding altogether; don't even run it through the
+     duplicate CC control code detection. Some MPEG-2 streams
+     apparently encode all captions with 0, 0 interleaved. I am not
+     sure if this interleaving conforms to the EIA-608 standard, but
+     checking for it fixes rare captioning problems with some DVDs.
+  */
+  if (c1 == 0 && c2 == 0)
+    return;
+
+#if LOG_DEBUG >= 3
+  printf("decoding %x %x\n", c1, c2);
+#endif
+
   if (c1 & 0x60) {             /* normal character, 0x20 <= c1 <= 0x7f */
     cc_decode_standard_char(this, c1, c2);
   }