[ILUG] No Limits ? - No Service !

Colm Buckley colm at tuatha.org
Tue May 1 12:27:55 IST 2001


> == >>> == Jerry Walsh
>> == me

>>> pal is 50hz, 100hz if interlaced.

>> Nope, it's half that.  Normal broadcast PAL is 50 half-frames per
>> second, giving a full-screen update rate of 25 frames per second.

> It's half that? you're saying its 25hz and 50hz when interlaced?
> Hertz and frames aren't the same thing - Hertz is per second, so if
> you get a half a frame 25 times per second then you're ending up
> with 12.5 frames a second.

I'm well aware of the definitions of Hertz and frames, Jerry.  In the
PAL broadcast standard, the vertical refresh rate is indeed 50Hz, but
only half a frame is transmitted per 50Hz cycle - odd lines on one
cycle then even lines on the next.  Therefore, it takes two cycles to
transmit a complete frame; resulting in 25 frames per second.  Which
is what I said.

          Colm

-- 
Colm Buckley @ NewWorld Commerce
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If a pig loses its voice, does it become disgruntled?




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