V4L/DVB (11863): cx18: Initial attempt to get sliced VBI working for 625 line systems

Initial changes to get sliced VBI for 625 line system working.  This is patch
is untested.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/cx18/cx18-streams.c b/drivers/media/video/cx18/cx18-streams.c
index 41a1b26..a080039 100644
--- a/drivers/media/video/cx18/cx18-streams.c
+++ b/drivers/media/video/cx18/cx18-streams.c
@@ -371,9 +371,15 @@
 		 * Tell the encoder to capture 21-4+1=18 lines per field,
 		 * since we want lines 10 through 21.
 		 *
+		 * For 625/50 systems, according to the VIP 2 & BT.656 std:
+		 * The EAV RP code's Field bit toggles on line 1, a few lines
+		 * after the Vertcal Blank bit has already toggled.
+		 * Tell the encoder to capture 23-1+1=23 lines per field,
+		 * since we want lines 6 through 23.
+		 *
 		 * FIXME - revisit for 625/50 systems
 		 */
-		lines = cx->is_60hz ? (21 - 4 + 1) * 2 : 38;
+		lines = cx->is_60hz ? (21 - 4 + 1) * 2 : (23 - 1 + 1) * 2;
 	}
 
 	data[0] = s->handle;