Quote:
Originally Posted by Triplec4
The TV I have connected it too is a panasonic 86cm ws approx 5 yrs old, it does not have compsite connections however does have scart sockets and s-video...
The thing that does concern me is when the desktop etc is loading the screen flickers and switches modes so to speak and seems to be struggling with it, the resolution is 800x600
I have also noticed a patch of colour deformation similar to placing a magnet close to the screen in one area but dissapears when back to normal tv is this normal, only see it when desktop is displayed its not noticible during playback. any ideas
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Hi Triplec4,
I've worded this reply in a general sense so that hopefully others may find it useful too.
Firstly, about the SCART connector: With its 21 pins, there is a pin permanently dedicated for a composite video signal (not that you would normally want to make use of it unless you had to).
And there are another three pins on the SCART connector which can be used for a choice of either S-Video, RGB, or Component connections. But note that these three choices are mutually exclusive (ie only one can be used at a time) -and are also dependant upon what the equipment at each end is capable of supporting. (Obviously you need to choose a connection method which both equipments are capable of operating with).
With S-Video, in most applications this connection method is significantly superior to composite (with a major exception I’ll mention in a minute) -because unlike composite, S-Video theoretically allows a full bandwidth luminance signal for SD operation. But note that just like composite, the S-Video specification itself does not cover anything beyond SD operation. Thus, if your TV has S-Video as its highest-spec connection method, it would be unwise for the TV’s health to send it anything other than an SD signal. (Although 800x600 should be OK though).
Now, here’s the hidden gotcha with S-Video coming from an HTPC!
Most PC graphics cards are very lazy -because they don’t send out the correct full-bandwidth luminance signal on their S-Video port! Instead they simply pass on the limited-bandwidth version that they generated for the composite port! This gives people a bad impression of S-Video. And no wonder, because with most PC graphics cards, the picture sent out on S-Video is little better than composite! (This issue doesn’t apply to other S-Video connected equipments though).
Alternatively, if your TV was able to support a Component connection, and your computer supported it too, then you could get a better quality picture (even with SD) than that provided by the most likely ‘hobbled’ S-Video port on the graphics card. And remember, if the equipments at each end can handle component, the SCART connectors themselves can certainly handle it...
Regarding the screen flickering at startup time. When your PC first starts up, it won’t be in your desired display mode of either 720x576 or 800x600 initially -because that will only start happening when Windows/MCE starts running. During the initial startup display, the video signal will be momentarily in a basic text mode which has different (usually lower) scan rates. And because most analogue TV’s usually have the electronic equivalent of a flywheel designed as part of their scan circuitry, it is common for them to take a while to re-synchronise when the video signal changes. A good way to avoid that issue is to not select the PC signal at the TV until the PC has fully started up & Windows/MCE is fully running.
Finally, regarding the patch of colour deformation you have seen on the desktop display: Are you certain that this is the only time it is present? Could it be that it is more noticeable because the desktop is a familiar unchanging display? -Because I’ve only seen that sort of thing when it is a permanent effect due to malfunctioning degaussing coils on the TV. (A common occurrence, but replacement of faulty thermistors is usually an easy fix for that).
Hope this helps
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Cheers
