ATSC HDTV video problem

[bdshaffer]

A 16:9 video on a 4:3 screen shouldnt require any negative values, which are the only ones that dont work on the Overlay renderer. In this case it should be using the 'LetterBox' aspect ratio, which is defined as:

<AspectRatioMode name="LetterBox" ratio="0,0.125,1,0.875" />

Many ATSC shows are broadcast as a 4x3 box in a 16x9 field. Why? I don't know. The black bars on the sides are part of the signal. It is necessary to use negative values to remove the black side bars.

[sub]

Ah, I see. Sorry - you cant do negative values in Overlay.

[foresglenn]

Many ATSC shows are broadcast as a 4x3 box in a 16x9 field. Why? I don't know. The black bars on the sides are part of the signal.

Yes, those black bars are a big problem in overlay mode, however I now have a (very) crude workaround:

Although you cannot use negative aspect ratio values in overlay mode, I have found that you can use negative values in the overscan control! I have not tweaked the values yet, but the following config.xml edit significantly increases the 4x3 box in a 16x9 broadcast:

Code:

<!-- overscan control (border size in pixels) -->
  <OverScanBorderX1>-50</OverScanBorderX1>
  <OverScanBorderY1>-50</OverScanBorderY1>
  <OverScanBorderX2>-50</OverScanBorderX2>
  <OverScanBorderY2>-50</OverScanBorderY2>
  <OverScanVideoAlso>true</OverScanVideoAlso>

Now, the big downside is that the OSD is too large and I don't think there is an f7 equivalent to dynamically change these settings. Perhaps someone knows how this can be done?

On the upside, I can now watch perfectly smooth 1280x720 ATSC programming and fairly smooth 1920x1080 ATSC programming on a 4x3 TV using a very modest system

(AMD Athalon XP 1800+, 256 MB, Nvidia GeForce FX 5200 128 MB, PureVideo decoder, Haupauge HVR-1600)

.

Thanks for everyones input in getting to this point!

[MythSpell]

I was in a similar situation to you. If you don't mind spending just a little bit of money, I'd suggest picking up a cheap Nvidia GeForce 6200 card off eBay. The AGP based ones, when used with the Nvidia PureVideo decoder, provide hardware acceleration for high-def MPEG2 video. That will make a dramatic difference in your ability the playback hi-def tv recordings smoothly. 1080i is no problem for me now with one of these cards and you can usually grab one on auction fairly cheap. I still have the link I was using when I was recently searching for them on eBay - it will list only AGP based 6200 cards and sort them by least expensive first. In case it might be of help, this is it: http://tinyurl.com/2jutce

Good luck with your setup. It is a real joy once you get full 1080 playing smoothly!