Tv card question

  Alf58 00:40 02 Sep 2007
Locked

Just fitted a Hauppauge tv card to my computer and am generally very pleased with the result. One issue is slightly annoying: when programmes end with rolling titles they are often blurred. Is this a fault with the TV card software or is it my monitor? My monitor A HPvs17e LCD with a response rate of 8 milliseconds.

Is there some ajustment I can make? My graphics card is a Radion X13 with 256Mb Memory.

  holme 09:15 02 Sep 2007

You need to appreciate that any TV card is a 'low-resolution' device as far as the computer monitor display is concerned. To put a number to that, the underlying TV display is only 576 pixels high (for PAL standard).

So if, for example, you try to expand the TV display to make it full-screen on your (presumably) much higher resolution monitor, the TV display has to be scaled up considerably. This isn't so bad for still images and moving pictures - but makes it /very/ difficult to read moving text. It's a fact of life and nothing to do with your graphics card or monitor.(It's rather more techie than that, but hopefully that explanation will suffice).

You may find that the clarity of the rolling titles will improve considerably if (oddly) you /reduce/ the TV display window size so that it's the same as the original picture, i.e. 576 pixels high. Some TV card software actually gives a readout of the TV window size; our Hauppauge cards do so you may be in luck.

So if you tweak the windows size to be /exactly/ 768x576 pixels (PAL TV display), that's exactly 1:1 scaling when overlaid onto your monitor display, even though in a relatively small window, but will be the clearest you can get.

As an alternative, if you happen to have a very high-res monitor (e.g. 1600x1200), you could bump up the TV window to 1536x1152 pixels, when the scaling ratio is then /exactly/ 2:1. That also should maximise the clarity of the text.

Finally, if you need to catch a particular title screen, you can always take a snapshot which will give a still image of 768x576 pixels. HTH.

  Jim_F 10:28 02 Sep 2007

I've noticed the same on LCD screens and put it down to lower refresh rates - the quality of the video captured seems unaffected.

I agree with the points made above also - a program called Dscaler (free) works with most Hauppauge cards and does a better job of displaying the video in realtime.

click here

  holme 11:51 02 Sep 2007

Many thanks for mentioning DScaler! We knew it existed but couldn't recall the name.

BTW, the de-interlacer works best on rolling titles if they're scrolling horizontally, but IMHO don't seem to have much of an effect for vertical scrolling titles /provided/ the TV window is first rescaled to exactly 1:1 (or 2:1) as I decsribed above.

But if you don't rescale the window, e.g. run the TV display full-screen, I agree it does have a beneficial effect. Thanks again for the nudge! :-)

  Alf58 13:55 02 Sep 2007

What an excellent answer. Thank you for your time.

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