[mythtv-users] 5200 or 6200

Jarod Wilson lists at wilsonet.com
Thu Jan 25 15:55:03 UTC 2007

Craig Courtney wrote:
> On Jan 25, 2007, at 12:11 AM, Jarod Wilson wrote:
>>>> fields vs frames my friend. two fields = 1 frame.
>>>> (1080 / 2) * 2 = 1080.
>>> I'm not sure what the fields vs frames 'proof' adds to the argument
>>> without taking into account the relative refresh rates of fields vs
>>> frames also. Fields are irrelevant with progressive video as whole
>>> frames are displayed.
>>> 1080p60 has twice as many pixels/s as 1080i60, as Jarod stated
>>> earlier:
>>> 1080i60 = (1920x540 pixels per field) x (60 interlaced fields per
>>> second) = 62,208,000 pixels/second.
>>> 1080p60 = (1920x1080 pixels per frame) x (60 progressive frames per
>>> second) = 124,416,000 pixels/second.
>> Yep, that's more or less the same math I came up with... Also, note
>> the mention on the page I linked to stating how 1080p60 raises
>> bandwidth requirements versus 1080i60 "from 1.493 Gb/s to nominally 3
>> Gb/s."
> This really sounds like apples to oranges.  1080i60, 1080p60, 1080xx   
> all display the exact same *resolution* on the display device which  
> is 1920 x 1080 (2,073,600 pixels).  Folks are absolutely right that  
> the data transmission speed and bandwidth (pixels per second)  
> required is radically different and under 1080i each pixels has  
> approximately twice as much latency between updates, but don't  
> confuse people by saying the resolution is double.
> Put in terms of relative refresh rates on computer monitors... no one  
> ever claims that running 1024x768 at 75hz gives you 25% more  
> resolution or pixels than running 1024x768 at 50hz.  It's the exact  
> same scenario here

No, it isn't. We're not talking about different Hz here. We're talking 
about interlaced versus progressive at the same refresh rate.

> the resolution and amount of pixels are exactly  
> the same the only thing that changes is how fast we update each pixel.

Okay, I understand your point that the entire image in both cases is 
1920x1080 pixels, but if you break it down on a frame by frame basis, 
its most definitely twice the resolution (1920x540 pixels per frame 
versus 1920x1080 pixels per frame at the same frame rate). I think we're 
just arguing semantics here now.


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