[mythtv-users] 5200 or 6200

Rich West Rich.West at wesmo.com
Wed Jan 24 19:18:31 UTC 2007


Jarod Wilson wrote:
> Steven Adeff wrote:
>   
>> On 1/24/07, Jarod Wilson <lists at wilsonet.com> wrote:
>>     
>>> On Jan 24, 2007, at 00:29, Stroller wrote:
>>>
>>>       
>>>> 1080i is 1920  1080 with every other horizontal line being updated
>>>> each refresh. Under 1080p _every_ line is updated each hz, so twice
>>>> as many pixels must be pushed (but the image won't look twice as
>>>> good, as I understand it; I guess it may even be indistinguishable to
>>>> many people, even if you have 1080p content).
>>>>         
>>> Its likely in many cases untrained eyes won't see the difference, but
>>> I'm pretty certain that the bigger the 1080p set, the more people
>>> would indeed notice the difference with 2x the resolution available.
>>>       
>> 1080p is not twice as many pixels as 1080i
>>     
>
> Yes it is. Or at least, it can be. (See below :)
>
>   
>> its a misconception on how
>> digital interlaced video works. In fact every frame of both formats
>> has the same number of pixels so in fact the pixel "rate"/count for
>> both at the same frame rate is the same.
>>
>> If you have a 1080p TV then the only difference you would notice on
>> 1080i content is dependent on the quality of de-interlacing between
>> Myth and your TV. In theory, 1080i broadcasts should be fully
>> IVTC-able and should have flags for proper 3:2 pull down, but they
>> usually don't. Many TV's use an mixed process that includes basic IVTC
>> which is more advanced than what Myth uses, but whether the results
>> are better would require some A:B tests as it would be very close.
>>
>> See
>> http://en.wikipedia.org/wiki/1080i#1080i_vs_1080p
>> for a good description on the differences.
>>     
>
> Okay, read it, and I read it to say that 1080p60 is indeed 2x the 
> resolution of 1080i60, but that 1080p24 and 1080p30 are more commonly 
> found in the wild today.
>
> Additional reference material:
> http://en.wikipedia.org/wiki/1080p#Broadcasting_standards
>   

Way off topic from the original poster's question, but I have found this
site as a good visual example of interlaced vs. progressive:
http://alvyray.com/DigitalTV/Naming_Proposal.htm

And this site for pixel/bandwidth information:
http://alvyray.com/DigitalTV/DTV_Bandwidths.htm

You'll see 1080p60 only on DVD's (high def ones, that is).  1080p24 and
1080p30 are OTA broadcast specs.  All of the above is US specific.

-Rich




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