[ILUG] No Limits ? - No Service !
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 Buckley @ NewWorld Commerce
Business: +353 1 4334334 / colm at nwcgroup.com / http://www.nwcgroup.com/
Personal: +353 87 2469146 / colm at tuatha.org / http://www.tuatha.org/~colm/
If a pig loses its voice, does it become disgruntled?
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