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My mate says there are 1080p broadcasts in USA?

Discussion in 'TVs' started by StooMonster, Oct 27, 2005.

  1. StooMonster

    StooMonster
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    My friend tells me that here in CA, USA really (half-term hols), there are HD broadcasts in 1080p.

    He says Discovery and iMax channel are broadcast in 1080p HD.

    Are his claims true? He swears I know nothing when I say HD broadcasts are limited to 720p / 1080i.

    StooMonster
     
  2. neilmcl

    neilmcl
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    This is what's currently being broadcast and I can't see any mention of shows in 1080p.

    http://www.hdtvgalaxy.com/broad.html

    Notice that most of the programming is in 1080i yet Sky are supposed to prefer 720p.
     
  3. sgauntlett

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    Could be 1080p but 1080p30...hence a movie channel with 3:2 pull down from film (24Hz) and natural history, often shot in 24, 25 or 30p.

    Sport and traditional television is 60Hz (or 50Hz in the UK) which limits to 1080i30 (1080i25) or 720p60 (720p50).

    The holy grail is 1080p60 (1080p50) but no-body produces or transmits it yet.

    This confusion is also often seen when people say HD-DVD and Blu-Ray will be 1080p.....yes they will be film at 1080p24 (unless they continue with the sin of 3:2 pulldown and make 1080p30)
     
  4. StooMonster

    StooMonster
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    We he's also been telling me that HD 1080p is at 30fps, which I find very weird as with 3:2 pull-down it would be 24p. He claims all 1080p is at 30fps, and uses page 8 of this Pioneer plasma brouchure http://www.pioneerelectronics.com/pio/pe/images/portal/cit_3424/52302337plasma.english.pdf to "prove" that HD is at 30fps.

    So sgauntlett,you're saying that 1080p30 is 3:2 pull-down and deinterlaced 1080i, but then with six frames per second inserted? And this is broadcast?

    StooMonster
     
  5. StooMonster

    StooMonster
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    Thank you, that's very useful. Mostly 1080i and not one 1080p, not a suprise to me.

    Not sure he'll accept this, he tells me that "a salesman in Circuit City told me that 1080p is what is used" and he doesn't believe Bulletin Boards / Forums as "that's just people's opinions"

    He also says that http://www.voom.com satellite network is all 1080p, but I can't find that on their site (or 1080i to be fair).

    StooMonster
     
  6. neilmcl

    neilmcl
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    I got my link directly from the Discovery HD Theater website so maybe he can believe them considering that's the channel that he thinks is broadcasting 1080p. You would have thought that they would advertise the fact thay they are using 1080p, wouldn't you.
     
  7. Nick_UK

    Nick_UK
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    From my experience (from my trips to the US) the guys in Circuit City are only slightly more clued up than those in Comet in the UK.
     
  8. sgauntlett

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    Generally broadcast systems work at 60Hz (50Hz in europe). This means that 24p is rarely broadcast so the 60Hz world usually uses 3:2 pulldown to convert from 24Hz to 60Hz fields for NTSC broadcast. Currently, to make life easier for the broadcasters, they do the same for 1080i60 however, if this is progressive withing the interlace format, it's usually called psf (progressive segmented frame). This can "film mode" usually be detected and extracted to 30p but it is still 3:2 pulldown from 24Hz. In Europe, life is generally easier and we simply speed the film up from 24Hz to 25Hz but also use this psf mode for broadcast.

    There are lots of explanations of 3:2 pulldown online if you want to know more, for example:
    http://www.projectorpeople.com/tutorials/pulldown.asp

    :)
     
  9. Stephen Neal

    Stephen Neal
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    The US OTA system - ATSC - supports 1080/24p and 1080/30p as transmission formats. However there is not a single broacaster using these formats for transmission, as channels can't switch formats during their transmission day, and 24p and 30p do not have the motion rendition ability of 60p or 60i formats, and no broadcaster is limiting themselves to 24p/30p motion rendition.

    HOWEVER - some broadcasters are shooting in 24p and 30p video and converting this to 60i for transmission. This means the signal you receive is 60i, but contains 24p or 30p source video (albeit with the vertical interlace resolution reduction)

    Similarly some broadcasters have agile MPEG2 encoders that detect the redundant fields in 24p carried in 60i and broadcast just a 24p/48i signal - however this is delivered to the TV as 60i still.

    AIUI there are NO 1080/24p or 30p broadcasts in the US.
     
  10. Stephen Neal

    Stephen Neal
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    Voom went belly-up a while back. Some (all?) of the channels they used to carry exclusively are now carried on other platforms. They were using, or about to use, MPEG4 - but they were buying 1080/50i shows from the BBC (like Later with Jools), and I'm sure we'd know if they were 1080p for broadcast.

    There are very few 1080/60p TVs that actually accept a 1080/60p input (most accept 1080/60i and convert to 60p internally) 1080/30p is not a standard interconnect format - as it would have to be frame-stored and frame-repeated for display - as 30p native display would be appallingly flickery. Many HD CRTs on sale in the US don't run their HD inputs via a frame-store.

    I'm pretty certain Voom receivers had 720p and 1080i outputs - but not 1080p.
     
  11. StooMonster

    StooMonster
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    neilmcl: yes I would think they would all be shouting that they are 1080p, but My Mate says they are not because so many of them are broadcasting in that format already!

    Nick_UK: that's exactly what I told him (from my trips and working here, and reading online forums ;)), and as an ex-pat Brit one would think he'd understand but he seems impressed with their "knowledge".

    sgauntlett: understand pull-down (of 3:2, 2:2, 3:3, etc.) perfectly myself, trying to get My Mate to understand is hard ... he was CEO of an internet advertising agency that did lots of video encoding and has strong opinions of how everything video works.

    Stephen Neal: lots of high quality detail, as ever, cheers. My Mate also says that BBC HD and Discovery haven't worked together in six years, and they have totally fallen out. I am under the impression, perhaps wrong, that Discovery HD is using BBC HD content; is his claim true?

    It's funny, I'm here in northern CA but My Mate doesn't have tv especially cable/satellite (only old 24" and DVD player) so I haven't had chance to see any HD adverts; we're also out in the styx, so it's a big trip to any shops to confirm anything. Sadly ... being geeky tech boys (of sorts) we've been bickering about this for weeks over the net, and have carried on discussions in person!

    StooMonster
     
  12. neilmcl

    neilmcl
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    AFAIK Discovery HD still use BBC content, The Blue Planet for example among others.
     
  13. Stephen Neal

    Stephen Neal
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    The BBC and Discovery are still very much working together AIUI. The Proms are shot in HD and shown on Discovery HD, as are documentaries like SuperVolcano, which are co-productions with the BBC in HD.

    The playout of BBC America in the US was handled by Discovery in Maryland I believe (though this may have moved to NY).

    As there are no 1080p BROADCASTs in the US, and Discovery and the BBC are still working together on HD content, I suspect your mate needs to check his facts a bit more carefully.
     
  14. Chris Muriel

    Chris Muriel
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    As Steve has said, there aren't any 1080P transmissions in the USA either via Satellite or OTA terrestrial (and not many devices to display in that format if there were).

    Chris Muriel, Manchester - member of USA satforums
     
  15. StooMonster

    StooMonster
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    Thanks guys!

    StooMonster
     
  16. Calleva

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    Just to complete some details from personal experience....

    The current crop of Broadcast HD MPEG2 encoders do not support 1080P24 broadcast - For a typical example see here.. http://www.thomsongrassvalley.com/products/transmission/hde/hde8100/

    Just because the standards permit it, it doesn't mean it actually happens!


    Voom have never broadcast 1080P - they were broadcasting 1080i/59.94 - I spent a few days in their uplink facility in New Jersey (if memory serves) testing some MPEG pre-processing products, and they did not have the capability of 1080P broadcast.
    A lot of their material was film and therefore effectively 1080P24, but all of it was broadcast with 3:2 pull down.

    Blue Planet was indeed sold to DiscoveryHD a couple of years ago, but of course it wasn't actually an HD production ! The original material was everything from DV to film, and all stops in between and was edited in SD, then upconverted for the HD channels. See here.... http://www.snellwilcox.com/knowledgecenter/casestudies/pdfs/BBC Blue Planet.pdf

    I guess I should also give my credentials,

    I have worked in TV for 24 years, and, until recently was a Technical Applications Engineer responsible for Restoration and Conversion at Snell & Wilcox.
    I'm probably better known here as RichardA but have changed my ID due to moving onto greener pastures not directly involved with this kind of kit.

    Hope this helps convert the dis-believer :rolleyes:

    All the best,

    Richard.
     
  17. 10bii

    10bii
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    Just to clarify a bit, and as you may know, American HD channels are dedicated, meaning there is no such thing as switching to other modes of resolution. Even when SD content is being shown it will be upscaled to fit the HD resolution, whether 720P or 1080i.

    Whenever 1080P is broadcasted it will likely be the same kind of deicated channel. Rumors are channels like ESPN (sports) are looking to be the first to broadcast in that format.
     
  18. Stephen Neal

    Stephen Neal
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    Yep - apparently they have done some lab tests to see what would happen to ATSC receivers IF a station did change format dynamically. Many receivers froze or crashed apparently...

    I had read that ESPN had stated they were interested in 1080p - but one hopes that they won't be going 30p or 24p for sports - as it would look horrible... Be interesting to see how they solve the production issues with 1080/60p - if they go to 1080/60p from 720/60p?
     
  19. Stephen Neal

    Stephen Neal
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    Hi Richard

    I think that .pdf is slightly out of date. AIUI The Blue Planet was originally post-produced in 625/50i SD and upconverted to HD with the Alchemist converter for the sale to a Korean HD broadcaster, who was happy with the quality of the upconversion. That bit is what is covered in the .pdf.

    HOWEVER - when Discovery bought the series, AIUI they paid for the film material to be retransferred in HD, and the show was re-cut, with the HD film transfers incorporated, and only the SD video originated stuff requiring an SD-HD upconversion?
     
  20. 10bii

    10bii
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    It makes sense for the stations to be broadcasting in one single format. HD is confusing enough for many without adding a switching of resolutions for the same station.

    Over time the simulcast SD version of the station, if there is one, will no longer be needed.
     
  21. Stephen Neal

    Stephen Neal
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    The point I was making is that whilst 1080/24p and 720/24p are both permissible broadcast formats, US broadcasters don't dynamically switch from 1080/60i or 720/60p for sports to 1080/24p or 720/24p for drama, even if they are shot in these formats respectively. Rather than convert the 24p stuff to 60i or 60p using 3:2 pulldown, and transmit at 60p or 60i permanently. (And require 3:2 pulldownd detection and removal in some cases - such as 72Hz display, which wouldn't be required if 24p delivery were used)

    However the test demonstrate that ATSC receivers wouldn't cope with this at all well - and given the practicalities of running a transmission system with multiple frame rates, I bet most broadcast engineers at the networks are grateful for this!
     
  22. 10bii

    10bii
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    I understand but I was simply saying, and clarifying, that they don't switch, period. :)

    Not aware of such tests so i couldn't comment.
     

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