[mythtv-users] interlaced vs not?

Grant Edwards grante at visi.com
Fri Apr 30 23:58:06 EDT 2004

On Fri, Apr 30, 2004 at 04:27:43PM -0700, Chris Petersen wrote:

>> Where did you hear of this definition?  I've never heard of
>> that before.
> I worked for Computer City in high school...

'Nuf said.

> We sold monitors labeled interlaced (old style, think of a
> brick wall with staggered bricks) or non-interlaced (trinitron
> style, all pixels line up evenly on a grid)..

The physical layout of the phosphor dots has nothing to do with
it. Interlaced refers to "drawing" the screen half of the scan
lines at a time.  Even lines, odd lines, even lines, etc.  In
NTSC video the "halves" are done at 60HZ (well close anyway),
so you get a complete frame rate of 30Hz.

The alternative is "progressive" scan in DVD terms: you draw
all the scan lines every time, all in order from top to bottom.
Before DVD players came along, everybody just called it

> Then came the weird ones like NEC which were triangles of
> pixels, or viewsonic's array of staggered dots.  Either way,
> many tv's are still the old staggered-style pixel layout, and
> there is software (early tv-out cards, anyway) that modified
> the "non-interlaced" vga signal so it would look better on a
> tv screen.

Wow.  They sure filled you full of it at Computer City.


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