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#482 Problems with AR correction when SAR is not 1:1


I'm getting an odd problem with video that doesnt have
a 1:1 SAR.

If I use content with a SAR set, ffdshow appears to get
the AR correction wrong.

An example you should be able to reproduce. DVD mpeg2
content, with a DAR of 16/9 and a DAR of 64/45.
Enabling AR correction in the resize results in in
ffdshow outputting as if it were 4:3.

I suspect this issue may be because the AR correction
calculations don't take correct account of the SAR?


  • cc979

    cc979 - 2006-01-22

    Logged In: YES

    i get the same with my geforce4 card, some don't like it
    16-9 overlay - try rgb32 output

  • John Richard Barberio

    Logged In: YES

    Not a renderer issue.

    I've tried this rendering to the Overlay Mixer, VMR7 and
    VMR9. And used both RGB and YUV output.

    I've taken image grabs of the frames from ffdshow, and they
    are being outputted resized to 4:3.

  • cc979

    cc979 - 2006-01-23

    Logged In: YES

    which media player do you use, mpc or something else ?

  • John Richard Barberio

    Logged In: YES

    This occurs in all applcations that use ffdshow. Including
    zoom player, mpc and ProgDVB.

    Bumping prio, since this results in incorect output.

    Sugested fixes...

    1) Get the AR calculations right. Take into account the SAR
    when working out how to reformat.
    2) Before any resize, stretch the picture to turn it into a
    1/1 SAR. (Sub optimal, since it turns it into a two-pass resize)

  • John Richard Barberio

    • priority: 5 --> 7
  • - 2006-10-02

    Logged In: YES

    I had the same problem.
    Output>overlay mixer have to be enabled.


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