Can someone explain why a TV channel doesn't broadcast a picture of a constant size?

spiderwheels

Portal Pro
October 28, 2009
101
18


During a typical program the size of the displayed picture changes slightly. Sometimes there are two thin black bars down each side of the screen (I mean thin - not the same as a 4/3 picture), sometimes there is a thin black border around the whole picture with a dashed grey line at the top edge and sometimes the picture completely fills the screen - and all this in the same program.

Can someone provide an explanation or a link.
:D
 

Paranoid Delusion

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  • June 13, 2005
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    Re: Can someone explain why a TV channel doesn't broadcast a picture of a constant si

    Pretty scarey hey, amazing what a normal tv can do in adjusting these pictures on the fly

    Mostly this is down to how the codec manages the image, if you select original as zoom mode, then change through a few channels you will see even more differences.

    That's why intelligent frame correction (IFC) is a good thing.
     

    mr viggo

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  • March 1, 2008
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    Re: Can someone explain why a TV channel doesn't broadcast a picture of a constant si

    My tv provider even broadcast some channels at 16:9 squeezed in a 4:3 format (hard to explain). The picture looks perfect when using stretched mode, weird. :)
     

    spiderwheels

    Portal Pro
    October 28, 2009
    101
    18
    Re: Can someone explain why a TV channel doesn't broadcast a picture of a constant si

    Pretty scarey hey, amazing what a normal tv can do in adjusting these pictures on the fly

    Mostly this is down to how the codec manages the image, if you select original as zoom mode, then change through a few channels you will see even more differences.

    That's why intelligent frame correction (IFC) is a good thing.
    Interesting looking plugin. Is it possible for this plugin to just stretch things a little bit - maybe make the picture about 5% bigger when it has those tiny black borders.
     

    Owlsroost

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  • October 28, 2008
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    Re: Can someone explain why a TV channel doesn't broadcast a picture of a constant si

    Yes - that's exactly what I use it for (plus changing zoom mode for 4:3 material) - I don't use it for black bar cropping.

    Tony
     

    spiderwheels

    Portal Pro
    October 28, 2009
    101
    18
    Re: Can someone explain why a TV channel doesn't broadcast a picture of a constant si

    Yes - that's exactly what I use it for (plus changing zoom mode for 4:3 material) - I don't use it for black bar cropping.

    Tony
    Great. I'll have a look at it on the weekend.
     

    wolfi_b

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  • April 10, 2008
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    AW: Can someone explain why a TV channel doesn't broadcast a picture of a constant si

    These tiny black bars are called overscan, normal CR TVs don't show them. You don't need a plugin to correct them, there is a simple option in the menu to crop the picture.
     
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