On 12/03/2005, at 6:59 PM, Robert Schlabbach wrote: > From: "Matthew Phillips" <linux-dvb@xxxxxxxxxx> >> 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 >> SD >> pictures I'm getting on some channels have, either at the top or >> bottom >> of the picture, a line of blank pixels which sometimes have some white >> streaks. > > 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 > line > 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 > application. 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, Matthew.
