X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fmedia%2Fvideo%2Fbt8xx%2Fbttv-vbi.c;h=8c9f0f7cf467734b1ef69e252f8ce6a86f3f1199;hb=9464c7cf61b9433057924c36e6e02f303a00e768;hp=63676e7bd635f6b403a69be86e0e24d602c56337;hpb=41689045f6a3cbe0550e1d34e9cc20d2e8c432ba;p=linux-2.6.git

diff --git a/drivers/media/video/bt8xx/bttv-vbi.c b/drivers/media/video/bt8xx/bttv-vbi.c
index 63676e7bd..8c9f0f7cf 100644
--- a/drivers/media/video/bt8xx/bttv-vbi.c
+++ b/drivers/media/video/bt8xx/bttv-vbi.c
@@ -31,16 +31,11 @@
 #include <asm/io.h>
 #include "bttvp.h"
 
-/* Offset from line sync pulse leading edge (0H) to start of VBI capture,
-   in fCLKx2 pixels.  According to the datasheet, VBI capture starts
-   VBI_HDELAY fCLKx1 pixels from the tailing edgeof /HRESET, and /HRESET
-   is 64 fCLKx1 pixels wide.  VBI_HDELAY is set to 0, so this should be
-   (64 + 0) * 2 = 128 fCLKx2 pixels.  But it's not!  The datasheet is
-   Just Plain Wrong.  The real value appears to be different for
-   different revisions of the bt8x8 chips, and to be affected by the
-   horizontal scaling factor.  Experimentally, the value is measured
-   to be about 244.  */
-#define VBI_OFFSET 244
+/* Offset from line sync pulse leading edge (0H) in 1 / sampling_rate:
+   bt8x8 /HRESET pulse starts at 0H and has length 64 / fCLKx1 (E|O_VTC
+   HSFMT = 0). VBI_HDELAY (always 0) is an offset from the trailing edge
+   of /HRESET in 1 / fCLKx1, and the sampling_rate tvnorm->Fsc is fCLKx2. */
+#define VBI_OFFSET ((64 + 0) * 2)
 
 #define VBI_DEFLINES 16
 #define VBI_MAXLINES 32