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From: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
To: linux-kernel@vger.kernel.org
Subject: [2.6 patch] PAL-M support fix for CX88 chipsets
Date: Tue, 03 May 2005 09:48:24 -0300	[thread overview]
Message-ID: <42777318.2070508@brturbo.com.br> (raw)

    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;
 }


             reply	other threads:[~2005-05-03 12:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-05-03 12:48 Mauro Carvalho Chehab [this message]
2005-05-03 15:38 ` [2.6 patch] PAL-M support fix for CX88 chipsets 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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