1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

How long before a true 576p tv?

Discussion in 'Televisions' started by AndersR, May 19, 2004.

  1. AndersR

    AndersR
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    When will we ever see a televison that is capable off displaying a true 576p resolution?
    I remember reading that panasonic intends not to introduce pal-progressive tvs and dvd-players in europe. This seems to be the case as panasonic has never advertised a pal-prog product. The general consensus on avSforum seems to be that currently the top-dollar tv's in the U.S. are limited to 480p. Some new models advertise 1080i or 720p functionality, but I think they downconvert the signal to 480p or maybe 540p - if we are lucky.

    Though i have been looking forward to a true 576p tv, I just dont see it happening, in the near future, and I find it hard to trust that the current new pana/jvc/thomson models are capable of displaying a full pal prog signal (even if people on this forum are convinced that this is so) because of the fact that this is not beeing advertised, and because it is not even possible in the U.S.

    I must admit that I am dissapointed that it is not yet possible to buy a 576p tv, especially considering that pc monitors and companies like monovision in the U.S. easily beats these low resolutions and have done so for years.


    rant over.
     
  2. bonzobanana

    bonzobanana
    Member

    Joined:
    Aug 21, 2001
    Messages:
    3,426
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Yeovil
    Ratings:
    +218
    Theres nothing particularly hard about producing a full resolution pal progressive image and tubes are certainly capable of it. In fact frankly a tv tube capable of 720x576 which is 28" to 36" in size is incredibly easy and cheap now. Don't forget 17" monitors have the progressive pixel resolution of higher than 1024x768 and cost peanuts now. I think the main problem is getting a high enough refresh rate. Many manufacturers go for a 100hz double field rate option in preference to a 50hz progressive image which is more flickery. If you want a progressive set its probably worth going for one with a 75hz minimum refresh rate for progressive. However many people are quite happy with a 50hz progressive image even those using a rptv. Certainly I wouldn't have a problem watching a 50hz progressive image on a 28" tv.
     
  3. cosaw

    cosaw
    Active Member

    Joined:
    Jun 14, 2003
    Messages:
    753
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Stockport, Manchester
    Ratings:
    +19
    At the same time though we'd want progressive scan broadcasts, but that's probably even less likely to happen. Afterall if you're gonna shell out on a prog scan device then you wouldn't really only want to view de-interlaced images with associated artifacts when you could have the real thing.

    I think we're in for a long wait :(

    Simon
     
  4. bonzobanana

    bonzobanana
    Member

    Joined:
    Aug 21, 2001
    Messages:
    3,426
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Yeovil
    Ratings:
    +218
    Well I was thinking more of dvds and you can get a lovely progressive image with pal dvds of the full 576 line resolution. I did think though that live broadcasts could be effectively de-interlaced without too many problems. Certainly the current progressive solutions are a lot better than watching the same material in interlace mode. However I must admit my progressive display is a AE100 projector and it has a cough.. ntsc optimised panel of 858x484 and so can't do the full pal progressive resolution. However pal progressive material still looks fantastic on it. Surely buying a progressive tv with a pal spec tube will give a full pal progressive image. I'm sure sky will be the first to offer a decent high definition service in the uk and we will pay loadsa money for it too.
     
  5. cosaw

    cosaw
    Active Member

    Joined:
    Jun 14, 2003
    Messages:
    753
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Stockport, Manchester
    Ratings:
    +19
    Yep, I pretty much agree with what you're saying and I know dvd can look great in the way you described afterall I do watch dvd's on my PC from time to time. I know the technology gets better all the time to compensate but why compromise when you can go the whole hog.

    As regards dvd isn't it a contentious issue as to whether dvds are encoded progresive or interlaced? Has anyone got a definitive answer? I'd like to think and don't most beleive they are encoded progresively it would only seem logical. If so dvd is obviously one of the best sources for prog scan and de-interlacing shouldn't be an issue for display on a progressive device.

    Anyway if we do get to a time where de-interlacing isn't neccesarry we will probably look back at de-interlaced examples and be glad we made the next step.

    We live in hope.

    Simon
     
  6. Goose74

    Goose74
    Active Member

    Joined:
    Sep 24, 2002
    Messages:
    805
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Romsey
    Ratings:
    +12
    well what we REALLY want is 1080p capable telly! :) for out shiny new HD-DVD players!
     
  7. tutu

    tutu
    Active Member

    Joined:
    Apr 28, 2004
    Messages:
    2,217
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    48
    Ratings:
    +58
    Well apparently the JVC HV32D40 does..

    "Component Input for PAL Progressive: Compatible with HD1080i (HD1125i) signal" according to the JVC website.
     
  8. Goose74

    Goose74
    Active Member

    Joined:
    Sep 24, 2002
    Messages:
    805
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Romsey
    Ratings:
    +12
    yes but that isnt that the equiv of pixel plus ie it just interpolates the extra info?
     
  9. cosaw

    cosaw
    Active Member

    Joined:
    Jun 14, 2003
    Messages:
    753
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Stockport, Manchester
    Ratings:
    +19
    At the end of the day I think i'd prefer 720p than 1080i, but 1080p perhaps in the year 3000.

    Simon
     
  10. shortround

    shortround
    Active Member

    Joined:
    Sep 3, 2003
    Messages:
    418
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Ratings:
    +43
    dvd's are encoded interlaced in so far that each consecutive field stored on the dvd contains half a frame (either the odd or even scanlines). each frame is then 'flagged' so that a progressive scan dvd player knows which two fields to put together and send to the display as one complete frame. this is why you get varying qualties of prog scan players because some are better at deinterlacing than others. a lot of dvd's have the prog scan flags at incorrect places and therefore a player with a more intelligent chipset can detect these mistakes and rectify them before the signal reaches the display.

    if you were to record the dvd's in a true progressive way (ie. each field is one complete frame) then it would mean 90% of people wouldn't be able to watch dvd's as they don't have a prog scan capable display. once the transition is made and most people have prog scan tellies then i'm sure the media will move along accordingly and encode in a true progressive way.
     
  11. cosaw

    cosaw
    Active Member

    Joined:
    Jun 14, 2003
    Messages:
    753
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Stockport, Manchester
    Ratings:
    +19
    Thanks for the explanation shortround. Perhaps you can clear my thinking up on this a little further.

    So what you are saying is that if it weren't for the discrepencies in attaching flags to the material the encoding would be essentially the same as true progressive. i.e. you can extract the original film frame at that discrete point in time.

    The only reason I ask is that I've been led to beleive that interlaced broadcasts and video recordoings work differently, example where f stands for field:

    Interlaced broadcast over time at recording:

    f1 f2 f3 f4 f5 f6 f7 f8 f9 etc.
    Time ___________________>

    Interlaced storage on dvd over equivalent time:
    f1 f3 f5 f7
    f2 f4 f6 f9
    Time ____>

    I hope you can understand the distinction I am drawing. i.e. we have the same amount of frames in each example but with the broadcast, or video, time has moved on during the recording of each field so that f1 is from an earlier period in time than f2, essentially a different picture in real life. Alternately in the dvd example f1 and f2 are from the exact same point in time or in this case the actual frame of the film. Is this incorrect?

    Hope you can help, I'm trying to fully undersand why 100Hz tvs can't get 50 original broadcast fields to 100 by just repeating the fields twice, without the introduction of motion problems. Secondly, if my above hypothesis if wrong, I would assume it would mean that if you had a 100Hz progressive display you could succesfully de-interlace a 50Hz broadcast to fully progressive without motion problems or extra processing needed the same as you have described with dvd.

    Thanks.

    Simon
     
  12. shortround

    shortround
    Active Member

    Joined:
    Sep 3, 2003
    Messages:
    418
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Ratings:
    +43
    no, there is no difference in the basic method between an interlaced broadcast and a video/dvd recording. the top example in your diagram is correct in both cases.

    here is a clearer example (where f = field and fr = frame).

    interlaced____ f1 f2 f3 f4 f5 f6
    _____________ \ / __\ / _ \ /
    progressive____fr1 __fr2__fr3

    the duration for these 6 fields would be 6/50th's of a second (50hz). the duration for showing the frames progressively would be the same because each complete frame would be present on screen for 2 refreshes instead of just 1.

    to properly deinterlace a broadcast would mean delaying the first field by 1/50th of a second and holding it in memory and waiting for the second field to arrive so they can be put together before being displayed on the tv screen (which is what a prog scan dvd player does).

    as for the motion artifacts created by 100hz technology, i'm not really sure why this occurs as i haven't really looked into it. suffice to say that 100hz is not the same as 50hz progressive. it simply shows each field for 2 refreshes per 1/50th of a second instead of just 1 so you will still get interlace artifacts. perhaps showing an interlaced picture twice as fast is the reason we get even more artifacts with 100hz?

    note: excuse the horizontal lines in the diagram but the post won't allow me to type more than one space in a row for some reason?
     
  13. cosaw

    cosaw
    Active Member

    Joined:
    Jun 14, 2003
    Messages:
    753
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Stockport, Manchester
    Ratings:
    +19
    Sorry, looking back at my post it's a bit ambiguous. In my previous diagram the duration of time in both examples is the same. The concept that I'm trying to explain is easy to overlook without a decent example, an inadequacy on my part. :blush:

    Yes I understand and agree with all that you've said. My issue is more about the recording of the material and what is actually stored on the media. When I talk about discrete points in time I mean any point in time when a camera takes a picture. I'll try and clarify with a sketch. For convenience it is taken that film runs at 25fps instead of 24 just like on a pal dvd.

    [​IMG]

    Picture 1: take one picture, use half the lines (odd)
    Picture 2: take one picture, use half the lines (even)
    i.e. there is movement between picture 1 (field 1) and picture 2 (field 2)

    Picture a: take one picture - split into lines even and odd for dvd storage
    Picture b: take one picture - split into lines even and odd for dvd storage
    i.e. there is only movement between picture a and picture b, no movement between fields of the same frame.

    As I say this is easy to overlook as it does at first sight seem to be unnatural - it isn't the first conclusion you'd come to. It's just something that's become fixed in my head to do with the 100Hz issue as described previously.

    Hope that's clarified my idea and you can put me straight on the matter. So do the "Video" and "Film" methods both exist or is it all done as shown in the "Film" method (as would truly seem logical independent of display device)?

    Thanks again,

    Simon
     
  14. shortround

    shortround
    Active Member

    Joined:
    Sep 3, 2003
    Messages:
    418
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Ratings:
    +43
    ahh right, i think i know what you're getting at now. for example, if you were shooting the image of a car going past with your home video camera, then by the time field 2 is captured, the car would have moved slightly further forward from when field 1 was captured, so each field is from an entirely separate moment in time.

    i'm not really sure on this point. i can only assume that video cameras used in professional industry are capable of capturing images progressively at 25fps instead of interlaced 50 fields per second. i may be completely wrong on that so maybe someone could clarify? i would hope it's only an issue that would affect home video cameras. obviously viewing video material recorded at 50hz interlaced on a prog scan dvd player would offer no real benefit since each field is from a separate moment in time, and therefore deinterlacing them wouldn't make any difference?
     
  15. cosaw

    cosaw
    Active Member

    Joined:
    Jun 14, 2003
    Messages:
    753
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Stockport, Manchester
    Ratings:
    +19
    You've hit the nail on the head. :smashin: As I said it's easy to overlook without being explicit.

    Anyway I'm sure someone out there knows!

    I assume it would have adverse effects as each whole frame would exhibit a smeared effect. I'm trying to persuade myself that my understanding is incorrect. It's probagbly like you say that doubling to 100Hz simply amplifies the original interlaced artifacts. If this is the case then the only good way to acheive higher refresh rates is via a progressive scan device. Somehow I feel we should have had mainstream prog scan sets before 100Hz sets instead of what is evidently the other way round.

    Time to give my brain a rest I think. :)

    Simon
     
  16. Paul Atreides

    Paul Atreides
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    When they've milked the average customer dry.


    We are the minority and thus exert no pressure on the situation.
     

Share This Page

Loading...