[mythtv-users] High end, state of the art Myth Frontend

[Michael T. Dean]

On 09/18/2013 01:57 PM, Andre Newman wrote:
> On 18 Sep 2013, at 18:33, "Michael T. Dean" wrote:
>
>> On 09/18/2013 12:40 PM, Gary Buhrmaster wrote:
>>> On Wed, Sep 18, 2013 at 4:16 PM, Joseph Fry wrote:
>>> ...
>>>> Agreed!  They should have done away with interlaced with all HD
>>>> formats, there was no technical reason to keep it.
>>> Selective memory there?  There were some technical
>>> justification to keep it at the time that the standard was
>>> being decided (the '80s), although you may not agree
>>> with the reasoning (or the requirements), and I would
>>> agree that today some of those reasons are less
>>> convincing (partially as a reflection of 30 years of
>>> Moore's law and what you can put inside the box).
>> Yeah, the main justification for interlaced formats (for both NTSC and ATSC) was bandwidth.  They had 6MHz to use.  For ATSC, that meant 19.39Mbps for broadcast TV.  With the MPEG-2 encoders available at the time, that meant good picture quality up to 720p60 or 1080p30 or 1080i60.
> As much of a problem was moving uncompressed video around, 720p60 or 1080i60 (or 50) was doable(ish) at the time 1080p60 certainly wasn't and still causes headaches today.
>
>
>>   Now, ask Andre (who works in Sports TV) if he'd rather watch a sports broadcast in 1080p30 or 1080i60 (with good deinterlacing).  I'll bet he'll choose 1080i60.
> Yep, saw lots of football in 1080p25 last weekend at IBC, looked 'orrible, even with bad de-interlacing 1080i50 is better to watch for sports, even slow moving stuff like football ;-)
>
> The 8kp60 was much nicer, although seems really hard for the cameraman to get anything in focus…
>
>>   Would 720p60 be better?  Sure, if you're OK with having less than half as many pixels (spatial resolution).  (And the subjectivity of deciding which is better--720p60 vs 1080i60 vs 1080p30--is why the standard allows all of them.)
> Shame almost no-one uses the full set of standards, I have a recording of Yankee's vs Redsox baseball I think it is in native 720p60 which I watch when I need re-assuring that Sports TV isn't all crap and I don't even like Baseball!
>
>> Interlacing is simply a means of increasing the temporal resolution of a video at a given spatial resolution without a requirement for increased bitrate.  (And don't say, "You can't invent the pixels that are missing," because doing so from an interlaced signal is /much/ easier (and much more founded in reality)
> And is one big difference between a good de-interlacer and a bad one.

Exactly!  I think most people's problems with interlaced video are 
actually a reflection of the (often bad-quality) deinterlacers they've 
used/been subjected to.

>> than the, "Let's invent the 3 frames that would have come between these 2 frames we're given and display at 120Hz that LCDs do to make up for LCD technology's inherent limitations when used for video.)
> It should be noted that when I mentioned 720p120 I was talking about real, proper, captured p120 none of this invented LCD gibberish.

Right.  I had understood that, but just wanted to mention that 
deinterlacing is actually no worse (I'd even say much better than) what 
LCDs that many users probably love are doing.  Apologies if I confused 
anyone else with the mention.

Mike