[linux-dvb] Display artifacts with VisionPlus (Twinhan) DVB-T card
linux-dvb at mattp.name
Sun Mar 13 03:02:59 CET 2005
On 12/03/2005, at 6:59 PM, Robert Schlabbach wrote:
> From: "Matthew Phillips" <linux-dvb at mattp.name>
>> Hello all, I'm having some problems with some Australian DVB-T
>> channels, which I'm hoping someone here might have a clue about. The
>> pictures I'm getting on some channels have, either at the top or
>> of the picture, a line of blank pixels which sometimes have some white
> The line at the top is WSS (Wide Screen Signalling) as specified in
> ETSI EN
> 300 294. The first half of PAL line 23 is specified to carry WSS, the
> second half live video. Some broadcasters "blacken" this part of the
> when encoding their analog PAL source for digital broadcasting, others
> (like yours) don't.
> It's not a bug on the receiving end. If you don't want "overscan"
> areas to
> be visible, you should look for an overscan cropping feature in your TV
OK. So you mean that broadcasts from digital sources shouldn't have the
WSS artifacts? That might explain why it comes and goes.
I have a 4:3 TV and most SD here is 16:9, so I don't have much choice
as to seeing overscan at the top of the screen if I don't want to crop
the left and right. So the next thing to look at is if I can get MythTV
to do some cropping.
Thanks for the info,
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