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* [2.6 patch] PAL-M support fix for CX88 chipsets
@ 2005-05-03 12:48 Mauro Carvalho Chehab
  2005-05-03 15:38 ` Randy.Dunlap
  0 siblings, 1 reply; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2005-05-03 12:48 UTC (permalink / raw)
  To: linux-kernel

    This patch fixes PAL-M chroma subcarrier frequency (FSC) to its 
correct value of 3.5756115 MHz and adjusts horizontal total samples for 
PAL-M, according with formula Line Draw Time / (4*FSC), where Line Draw 
Time is 63.555 us.
     Without this patch, the Notch subcarrier filter was trying to 
capture using NTSC-M frequency, which is very close, but not equal. This 
could result in Black and White or miscolored frames.

-----

diff -puNr linux-2.6.12-rc3.org/drivers/media/video/cx88/cx88-core.c 
linux-2.6.12-rc3/drivers/media/video/cx88/cx88-core.c
--- linux-2.6.12-rc3.org/drivers/media/video/cx88/cx88-core.c   
2005-04-20 21:03:14.000000000 -0300
+++ linux-2.6.12-rc3/drivers/media/video/cx88/cx88-core.c       
2005-05-03 09:23:21.000000000 -0300
@@ -736,6 +736,9 @@ static unsigned int inline norm_fsc8(str
 {
        static const unsigned int ntsc = 28636360;
        static const unsigned int pal  = 35468950;
+        static const unsigned int palm  = 28604892;
+
+       if (V4L2_STD_PAL_M  & norm->id) return palm;

        return (norm->id & V4L2_STD_625_50) ? pal : ntsc;
 }
@@ -749,6 +752,8 @@ static unsigned int inline norm_notchfil

 static unsigned int inline norm_htotal(struct cx88_tvnorm *norm)
 {
+       // Should allways be Line Draw Time / 4FSC
+       if (V4L2_STD_PAL_M  & norm->id) return 909;
        return (norm->id & V4L2_STD_625_50) ? 1135 : 910;
 }


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2005-05-03 18:17 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2005-05-03 12:48 [2.6 patch] PAL-M support fix for CX88 chipsets Mauro Carvalho Chehab
2005-05-03 15:38 ` Randy.Dunlap
2005-05-03 17:43   ` Mauro Carvalho Chehab
2005-05-03 17:52     ` Randy.Dunlap
2005-05-03 18:04       ` [2.6 patch] PAL-M support fix for CX88 chipsets - final version :-) Mauro Carvalho Chehab
2005-05-03 18:11         ` Randy.Dunlap

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