[mythtv-users] Myth scaling/deinterlacing vs Faroudja
Michael T. Dean
mtdean at thirdcontact.com
Tue Jun 27 18:15:33 UTC 2006
On 06/27/2006 01:31 PM, Brad Templeton wrote:
> On Tue, Jun 27, 2006 at 11:42:00AM -0400, Michael T. Dean wrote:
>> On 06/24/2006 08:58 PM, Brad Templeton wrote:
>>> It's a shame the HD committee didn't sit
>>> down and say, "You know, by the time people can actually afford 1080
>>> line displays, 1080p should not be a problem." Done at 30fps if that's
>>> what the broadcast channel had bandwith for.
>> If by, "HD committee", you mean the ATSC, they did. See
>> http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html for the 18 ATSC
>> formats, including 1080i60, 1080p30, 1080p24, 720p60, 720p30, 720p24
>> (and then all the 480 line resolutions).
>>> Particularly jarring is that many of the HD things, like movies, are shot
>>> at 24fps, non-interlaced.
>> Which can be handled by ATSC (1080p24 or 720p24).
>>> I don't know whether the 1080i shows that
>>> are shot on video today are shot at 1080i or some other rate.
>> AIUI, many (most?) dramas are shot at 24fps and, for broadcast at
>> 1080i60, converted using a 3:2 pulldown (or, more often, 2:3 pulldown,
>> which is typically referred to as 3:2 pulldown ;).
>> However, ATSC doesn't require the broadcast at 1080i60. Whether those
>> channels that have chosen 1080i actually broadcast material at 1080p30
>> or 1080p24 I can't (yet) tell you... However, I've never seen any
>> standard that prevents them from doing so. (I think it's more likely
>> expense of equipment for handling multiple source formats that would
>> prevent them from doing so if they don't.)
> The ones here are broadcasting interlaced, and I expect that's common in
> other cities. More to the point they have, as far as I can tell, all
> decided not to ever switch formats.
That's the part I wasn't sure about. I had heard both ways, but heard
more people saying they don't switch...
> SDTV shows are upscaled to 1080i,
> 24fps movies, sports etc. are shown at 1080i. They also do SD sub-channels
> at 480i, I have not seen anybody do 480p. It's possible the 720p stations
> may switch from 30fps to 60fps, as I have seen some 720p recordings myth
> stutters on, and some it displays more easily than 1080i, but I haven't
> examined them for frame rate.
Interesting. I'll have to watch for changes to formats once I start
recording HDTV. I'd love to have definite proof of format changes and
see what's the determining factor--station, network, content,
progressive/interlaced (i.e. never switching between the two), etc.
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