The patch number 9892 was added via Andy Walls <awa...@radix.net>
to http://linuxtv.org/hg/v4l-dvb master development tree.
Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel
If anyone has any objections, please let us know by sending a message to:
v4l-dvb-maintai...@linuxtv.org
------
From: Andy Walls <awa...@radix.net>
cx18: VBI comment corrections and comments about VBI issues
VBI comment corrections to avoid future confusion about standards.
Comments on cx18 VBI implementation shortcomings that need resolution.
Priority: normal
Signed-off-by: Andy Walls <awa...@radix.net>
---
linux/drivers/media/video/cx18/cx18-driver.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff -r a1b0c8a95ebb -r f9791967fd3a
linux/drivers/media/video/cx18/cx18-driver.c
--- a/linux/drivers/media/video/cx18/cx18-driver.c Sun Dec 14 16:52:12
2008 -0500
+++ b/linux/drivers/media/video/cx18/cx18-driver.c Sun Dec 14 17:21:35
2008 -0500
@@ -614,18 +614,21 @@ static int __devinit cx18_init_struct1(s
* We use a BT.656 pxiel clock of 13.5 MHz and a BT.656 active line
* length of 720 pixels @ 4:2:2 sampling. Thus...
*
- * For NTSC:
+ * For systems that use a 15.734 kHz horizontal rate, such as
+ * NTSC-M, PAL-M, PAL-60, and other 60 Hz/525 line systems, we have:
*
- * (1/15,734 kHz) * 2 * 13.5 MHz = 1716 samples/line =
+ * (1/15.734 kHz) * 2 * 13.5 MHz = 1716 samples/line =
* 4 bytes SAV + 268 bytes anc data + 4 bytes SAV + 1440 active samples
*
- * For PAL:
+ * For systems that use a 15.625 kHz horizontal rate, such as
+ * PAL-B/G/H, PAL-I, SECAM-L and other 50 Hz/625 line systems, we have:
*
- * (1/15,625 kHz) * 2 * 13.5 MHz = 1728 samples/line =
+ * (1/15.625 kHz) * 2 * 13.5 MHz = 1728 samples/line =
* 4 bytes SAV + 280 bytes anc data + 4 bytes SAV + 1440 active samples
*
*/
+ /* FIXME: init these based on tuner std & modify when std changes */
/* CX18-AV-Core number of VBI samples output per horizontal line */
cx->vbi.raw_decoder_line_size = 1444; /* 4 byte SAV + 2 * 720 */
cx->vbi.sliced_decoder_line_size = 272; /* 60 Hz: 268+4, 50 Hz: 280+4 */
@@ -929,6 +932,11 @@ static int __devinit cx18_probe(struct p
}
cx->params.video_gop_size = cx->is_60hz ? 15 : 12;
+ /*
+ * FIXME: setting the buffer size based on the tuner standard is
+ * suboptimal, as the CVBS and SVideo inputs could use a different std
+ * and the buffer could end up being too small in that case.
+ */
vbi_buf_size = cx->vbi.raw_size * (cx->is_60hz ? 24 : 36) / 2;
cx->stream_buf_size[CX18_ENC_STREAM_TYPE_VBI] = vbi_buf_size;
---
Patch is available at:
http://linuxtv.org/hg/v4l-dvb/rev/f9791967fd3a3efb3d8b7da19c5610f0e6db413e
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