1080p source material ???

Discussion in 'Playback Devices' started by Sami Kallio, Apr 14, 2005.

  1. Sami Kallio

    Sami Kallio Screenwriter

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    http://www.ultimateavmag.com/thomasjnorton/305tjn/

    "But here's the rub: current HDTV sources are all either 720p or 1080i. There is no 1080p source material available to the consumer."

    Does it matter? There is no source material for 480p either, it is done by either the DVD player or the display device. Wouldn't 1920x1080 source then be both 1080i and 1080p capable?
     
  2. John S

    John S Producer

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    1080p is defined as an HDTV standard.. No source yet that I know of. But 1080i deinterlaced has got to be way great even though I have yet to see it in person.
     
  3. Sami Kallio

    Sami Kallio Screenwriter

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    Yes, but if you have 1920x1080, isn't it both 1080i and 1080p source? You just display it with higher frequency. Like 1280x720 is 720i/720p material. 720p isn't 1440i.
     
  4. John S

    John S Producer

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    On fixed pixel displays (Not CRT), there is no such thing as Interlaced....

    So for them to go above 720p, the next and only step was 1080p. Everything gets conveted to that for display.

    On a 720p panel, everything gets converted to 720p...
     
  5. Sami Kallio

    Sami Kallio Screenwriter

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    I don't see what that has to do with source material though. It is either 1920x1080 or 1280x720 for HD. So why would 1080i material be any different than 1080p material? Or is he saying there isn't 1920x1080 material?
     
  6. John S

    John S Producer

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    I know of zero 1080p source right now. Maybe in Japan?

    1080i would only need de-interlaced. 480p is better than 480i, so 1080p is going to be better than 1080i.

    But this is at the display level not the source. 1080p source will take a lot of bandwidth, I don't think we will see it for quite a while. I'm not sure what HD DVD puts out, or how it is encoded, I suppose they could do 1080p on it.
     
  7. Lee-c

    Lee-c Second Unit

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    HD-DVD can definitely have 1080p right on the disk. It has the capacity to hold a movie at 1080p.
    This removes any possibility of the t.v. not perfectly de-interlacing the image from 1080i
    to 1080p. I'd rather they put all movies on the HD-DVD disk at 1080p native, this way we don't
    have to even worry about which t.v.'s de-interlace better than others, because there will be
    no de-interlacing taking place at all.
     
  8. Sami Kallio

    Sami Kallio Screenwriter

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    So the material can be 1080p? DVD's are 480i, there is no material on DVD that is 480p.

    Progressive scan, as I know it, does not double your data/resolution. What it does is scan the information in sequantial order vs. interlaced. So my question still is what is 1080i material if it is not also 1080p material?
     
  9. Allen Longcor

    Allen Longcor Supporting Actor

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    I understand what you are saying, but as far as I know there are no discs that have 1080i info on them. So only HD cable/satellite services are providing 1080i material. I don't know if you could convert a 1080i source to progressive from a cable/satellite service.

    I think they are saying that native 1080p would provide double the information and that is where the confusion lies. If I understand you right you are asking that if there were 1080i DVD's right this minute, couldn't a progressive player display that at 1080p?
     
  10. Dmitry

    Dmitry Supporting Actor

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    My guess (although I might be wrong) is that 1080i material is a 1920x540, not 1920x1080.
     
  11. ChristopherDAC

    ChristopherDAC Producer

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    OK, here is a little bit of an answer to what may be your question.

    "Progressive" or "Interlaced" scanning refers to the method by which the horizontal scan lines into which the picture is divided are generated. It is virtually meaningless without specifying the frame rate. In standard NTSC or "SD 480i30" ATSC, the frame is scanned 30 times per second [nominally; the actual rate is generally 1/10 oof 1% lower]. Instead of starting at the top of the screen and running down to the bottom of the screen, scanning each line in turn, the camera scans the odd-numbered lines of the picture first and, upon reaching the bottom of the screen, returns to the top and scans the even-numbered lines in the same way. This procedure reduces screen large-area flicker and improves motion resolution as compared with a progressive 30 Hz scan.
    In the "720p60" ATSC format, the screen is scanned from top to bottom 60 times each second, without interlace. This produces a picture with little flicker and good motion resolution.
    In progressive formats with a frame rate less than 60 Hz, such as "1080p24", the whole image must be displayed several times during a single frame time in order to be of watchable quality, which requires digital memory circuits. High definition live pickups, including those transmitted as 720p60, are usually 1080i30 at the camera end for technical reasons. Images scanned from film are 1080*1920 still pictures, which could be encoded as 1080p24, 1080i30 with 3:2 pulldown, or really any other format, but the information conveyed in each encoding is the same. If encoded in an interlaced form, it would be entirely possible to "back out" the original image and display it progressively. If encoded in a progressive form, there would be little difficulty in converting to an interlaced form. In either case, however, the frame rate would have to be changed to allow prolonged viewing without serious eye fatigue.
     
  12. Sami Kallio

    Sami Kallio Screenwriter

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    Exactly, and that is what the info Christopher posted is saying. Double the framerate = progressive picture.
     
  13. John S

    John S Producer

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    The source is what it is..

    I don't understand your statement...

    On a fixed pixel display everything is played at the panels native resolution, it is scalled to it. So everything is played at 1080p or 720p or whatever it is.


    I'm obviously no getting the gist of the thread here is all. I can be dense at times.

    DVD is 480i it is played at 480i until some external thing makes it 480p or scales / upconverts it to some HD resaolution.

    1080i is a source spec from what I understand, so once again it is played as 1080i until something makes it 1080p or 720p or even 480p.

    1080p as a source will be 1080p and played as 1080p.....
     
  14. Allan Jayne

    Allan Jayne Cinematographer

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    >>> 1080i material is 1920 x 540, not 1920 x 1080
    Depens on how it was recorded. Proper recording of 1080i takes the pixels from 1080 unique vertical positions, otherwise it would be officially called 540p.

    >>> There is no 1080p source material
    Film source material provides enough content on a 1080i over the air HDTV broadcast to provide 24 complete 1080p frames per second. It does require a good de-interlacer (few exist so far) to deliver full frames made up with matching even and odd fields to the 1080p TV, creating 3-2 pulldown, 3-3 pulldown, etc. to match the TV's frame rate. (The HDTV broadcast channel will not accommodate 60 complete 1080p frames per second which true 1080p live video would contain.)

    Video hints:
    http://members.aol.com/ajaynejr/viddoubl.htm
     
  15. Sami Kallio

    Sami Kallio Screenwriter

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    The 1080p source would be 60 * 1920x1080 frames per second where the 1080i source would be 30 * 1920x1080 frames per second. Is 720p material 60 * 1280x720 frames per second, or is it actually 30 * 1280x720?

    Now to come to think of it, I understand the difference now. DUH!!! It is 30 different frames per second that is displayed, not just 1 same frame refreshed 30 times per second. What a dumbass I am for not thinking it through. Then again, can human eye really tell the difference between 30fps and 60fps? Film is close to PAL framerate (25fps) isn't it?
     
  16. Joe Szott

    Joe Szott Screenwriter

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    The second disc of the recently released Terminator 2 edition contains the film in 1080p format. I believe they use MPEG4 and other tricks to fit it on a DVD9 disc. Plus you pretty much need WMP9 and up to read it on a PC.

    For what it's worth, there you go...
     
  17. Jorge M

    Jorge M Stunt Coordinator

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    Let's not complicate the issue, which is 1080i is not the same as 1080p. The guy in the article is right saying nobody is broadcasting in 1080p.

    1080i scans 540 lines every 1/60 of a second. "1080p" at 60 Hz would effectively double the resolution, scanning 1080 lines in the same amount of time.

    You can take 1080i and turn it into 1080p just like you can take a DVD and turn it into progressive. As some have said, on a fixed-pixel display you would have to because they are inherently progressive. The source will still be 1080i.
     
  18. Sami Kallio

    Sami Kallio Screenwriter

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    Yep, I got the difference now and I re-read the article. He isn't saying that 1080p display with 1080i isn't going to look better than 720p. 1080i material is 60fps of 1920x540 or 30fps of 1920x1080?

    What I have heard is a lot of the broadcasts (1080i or 720p) aren't true HD either. The broadcast might be HD but the source could be upscaled from lower resolution material.
     
  19. Jorge M

    Jorge M Stunt Coordinator

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    Sorry, it took me a while to post. Glad to see you got it. [​IMG]

    I think that nowadays most HD broadcasts are true HD. I remember a couple of years ago (when FOX was still fighting HD I think) many football games were upconverted from SD to 720p, and you could tell that something just didn't look right.

    Of course even today a lot of HD material starts out as film (movies, ABC dramas, and NBC sitcoms come to mind), and so doesn't look as sharp as stuff shot in 1080i from the start. I guess it has to do with the film stock and the transfer.
     

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