1. Join Now

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

Is Progressive Scan really that good?

Discussion in 'Projectors, Screens & Video Processors' started by Jon Weaver, Oct 28, 2003.

  1. Jon Weaver

    Jon Weaver
    Member

    Joined:
    Aug 16, 2000
    Messages:
    6,156
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    133
    Location:
    Born in Bristol but now in Newport, (for my sins)
    Ratings:
    +715
    I have owned a Plasma for the past 12 months and am really happy with the PQ from my Pioneer 454 DVD and JSims RGB-VGA converter.

    However, now that Pal Progressive Players are emerging in my price range (i.e the Toshiba 530) I am tempted to finally go down the Progress Scan route.

    However, is it REALLY worth it? Is there a significant increase if PQ? I am tempted to borrow a NTSC PS player, just to get an idea of whether there is a substantial difference, but wonder if anyone has any experiences in this area?
     
  2. LV426

    LV426
    Administrator Staff Member

    Joined:
    Jul 14, 2000
    Messages:
    13,316
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Somewhere in South Yorkshire
    Ratings:
    +5,668
    For a few years, I've been using a Pioneer 737 (Progressive scan on NTSC only) with my VW10HT projector.

    I'd say that the difference, for the most part is subtle, but occasionally really shows itself. Perhaps the most recreatable and predictable difference (although by no means the only circumstance) is in the scrolling end titles of a movie, where the thin horizontal lines that appear in many characters of the text, no longer shimmer and flicker as they scroll.
     
  3. Rob.Screene

    Rob.Screene
    Active Member

    Joined:
    Sep 29, 2001
    Messages:
    1,272
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    66
    Location:
    Berks, England
    Ratings:
    +130
    All LCD's and Plasmas need a progressive-scan signal at some point internally for scaling the video to the panels's native resolution.

    I think nigel's projector would have been doing a progressive-scan conversion internally anyway, so his observations look to be comparing the DVD progressive-scan deinterlacing against the projector's progressive-scan deinterlacing.

    For TV users, I'd say NTSC progressive scan compared to normal interlaced NTSC DVD's should show a big increase in percieved vertical picture resolution, as it removes the horrid 3-2 pulldown where different film frames are combined to make 24fps film run at 29.97Hz interlaced NTSC.

    PAL transfers don't need this, so it doesn't need removing.

    For your plasma, we are really comparing using it's on-board deinterlacer or not. I've seen a Pioneer 433MXE de-interlacer and it wasn't ideal, certainly it was improved by feeding it a progressive-scan video signal.

    Most progressive-scan DVD players deinterlace using the cleanest digital video straight off the DVD's MPEG2 decoder.

    Compared to this, analog (S-Video or Component) connections to the projector/tv/plasma or an external deinterlacer (like the iScans) have the signal converted to interlaced analog, before being converted back to digital and then deinterlaced to progressive-scan.

    So, on-board progressive-scan should give better deinterlacing (assuming deinterlacing chips of equal performance) than a progressive-scan capable display because it skips a DAC and ADC pair of steps which add noise and apparently reduce deinterlacing effectiveness.

    regards,
    Rob.
     
  4. Dale Adams

    Dale Adams
    Active Member

    Joined:
    Jul 9, 2003
    Messages:
    175
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +15
    What does 3:2 pulldown have to do with 'perceived vertical picture resolution'? Now, motion judder I can understand. But vertical resolution? Please explain.

    - Dale Adams
     
  5. Gordon @ Convergent AV

    Gordon @ Convergent AV
    Distinguished Member AVForums Sponsor

    Joined:
    Jul 13, 2000
    Messages:
    14,150
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Living in Surrey, covering UK!
    Ratings:
    +2,968
    Rob,

    I'm afraid I'm with Dale here.

    For a start the on board de-interlacers in many DVD players are flag reading and as such are tripped up more often that picture information devices like external processors or Holo3D card.

    3:2 pull down does not remove judder related to getting 24 film frames in to 60Hz. Progressive scan devices just use the 2:3 pulldown sequence to recognise relationship of fields so they can re-constitute the original film frames and then show them in a 3:2 sequence.....with the same associated judder.

    PAL film source stuff requires recognition of the 2:2 sequence in order to correctly re-constitute the original film frames.

    So progressive scan done well should remove lots of interlace artifacts but done badly can be a mess.
     
  6. John Narayan

    John Narayan
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I have seen the sony DVPNS730 with a CRT projector and
    this unit does a very nice progressive scan output.

    Sony have included a flag overide button because many DVD'S have the incorrect flags on them.

    The unit also has 4 modes
    NORMAL -normal 576i
    FILM - film progressive 576p
    VIDEO - video progressive 576p
    AUTO - the player will read the flag data and
    chose what it thinks is best.

    anyhow the link below will give you more data.

    http://www.sony.com.au/product_detail_content.asp?CCod=18158&CCod2=16658&ProdCod=DVPNS730
     
  7. Rob.Screene

    Rob.Screene
    Active Member

    Joined:
    Sep 29, 2001
    Messages:
    1,272
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    66
    Location:
    Berks, England
    Ratings:
    +130
    I hear you guys.

    >For a start the on board de-interlacers in many DVD players are flag reading and as such are tripped up more often that picture information devices like external processors or Holo3D card.<<

    My cadence reading Holo3D drops PAL film mode occasionally. My flag reading TheaterTek software player doesn't, but then I force film mode, so perhaps my experience is coloured.

    >>3:2 pull down does not remove judder related to getting 24 film frames in to 60Hz. Progressive scan devices just use the 2:3 pulldown sequence to recognise relationship of fields so they can re-constitute the original film frames and then show them in a 3:2 sequence.....with the same associated judder.<<

    I assume you mean 3:2 pulldown removal Gordon. I see what you mean about it still giving 3:2 progressive judder when at 60Hz. I'm thinking of 3-2 pulldown removal itself, which gets 23.976fps, which at 47.952Hz or 71.928Hz is beautiful. It's all these chips that then double/tripple flash each frame to get to 60fps for HDTV/EDTV compatibility.

    >>What does 3:2 pulldown have to do with 'perceived vertical picture resolution'? <<

    When watching NTSC film sourced material, without film mode detection also called "3-2 pulldown REMOVAL", the deinterlacer will be combining pairs of fields from different frames when the extra fields are repreated from previous frames, because of the NTSC 3-2 pulldown encoded on the disc (or tape or Laserdisc).
    These combined frames are a blurring of even and odd lines of two different film frames, so hence they obscure the real detail, even from different scenes at scene changes.

    I've seen it when working with NTSC material when 3-2 pulldown removal has not worked correctly.

    NTSC 480p/47.952Hz and 480p/71.928Hz looks fab and pans perfectly to my eyes. Apparently though very few deinterlacer/scalers support this output mode though??

    Are we really discussing here if interlaced NTSC 480i/60 with 3-2 pulldown in-place then de-interlaced by an on-board panel deinterlacer pans better than 480p/60 NTSC progressive with 3-2 repeat of progressive frames?

    cheers,
    Rob.
     
  8. Dale Adams

    Dale Adams
    Active Member

    Joined:
    Jul 9, 2003
    Messages:
    175
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +15
    Rob,

    You wrote:

    But in a previous message you wrote:

    So why is it that PAL transfers, which use 2:2 pulldown instead of NTSC's 3:2 pulldown, don't have a problem with a non source-type adaptive deinterlacer combining fields from different film frames? With 2:2 pulldown, every other field pair has fields from different film frames, so you should see this more often than with 3:2 pulldown, not less often.

    Also, why wouldn't you get the same 'increase in perceived vertical picture resolution' with a 2:2 pulldown source as with a 3:2 pulldown source, assuming the deinterlacer was capable of removing both? While you don't explicitly state this, it's strongly implied in your original post.

    - Dale Adams
     
  9. Jayb

    Jayb
    Standard Member

    Joined:
    Feb 6, 2003
    Messages:
    149
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    19
    Location:
    Nottingham
    Ratings:
    +0
    I will admit that the last few posts have gone right over my head and maybe I will learn a little more about progressive scan over time with the help of the forums

    but so far my experience of progressive scan has been with a tosh 520 and 32zd26p, they can both handle ntsc PS and while watching a ntsc DVD you can toggle between progressive and interlaced........Trust me, even on a 32" screen it makes a big difference....:eek:

    So my advice with regards to ntsc progressive or interlaced is go progreesive.....:smashin:

    as for pal, sorry not a clue....:confused:
     
  10. Family Guy

    Family Guy
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Can I just add that the quality of the source (disc/broadcast material) needs to be taken into account as well...
    I used to own an iscan pro that did the de interlacing prior to the signal hitting my Sony HS1 PJ - which dosen't have an internal de interlacer AFAIK. Watching some programmes from Sky+ fed by s video into the iscan were terrible. Football being a prime example. Some DVD's also looked really bed as well - gangs of new York R2 being the prime example there. Jaggies everywhere and brick walls looking as though they were alive.
    I now have a Brainwave V880 which upscales material to 720p. I have had only one experience of a bad DVD through this - The Life Of David Gale. Parts of the scenery on this film appeared to be alive on this disc...really bad. Yet all other discs I have watched have been sublime and a real improvement over the iscan...the next firmware upgrade is going to include a 1080i 50hz option as well - which will remove the juddering I get on R2 discs if I watch them via 1080i 60hz.:)
     
  11. rscott4563

    rscott4563
    Standard Member

    Joined:
    Jan 21, 2003
    Messages:
    1,051
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    38
    Location:
    Cumbria
    Ratings:
    +1
    Well I know nothing about that particular PJ but I'm assuming its a LCD PJ which means it does have a de-interlacer as a digital display device such as an LCD or DLP PJ can only show a progressive image, it would be impossible for it to show the interlaced signal as it is.....
     
  12. Family Guy

    Family Guy
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I'm afraid you are wrong mate. My PJ tells me what signal is being output. When I watch sky it tell me I'm watching a 575(I know it should be 576 but the pj says 575)/50i. When I ran it through the iscan, it would tell me I was watching 575/50p.

    This isn't a digital PJ as far as I know. It has no DVI input and only goes up as far as svga with a native panel of 800 x 640 I believe...but I do KNOW it outputs an interlaced signal and I have no way of upscaling it inside the PJ. It only outputs what it receives.

    I would love someone to prove me wrong here, believe me...
     
  13. rscott4563

    rscott4563
    Standard Member

    Joined:
    Jan 21, 2003
    Messages:
    1,051
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    38
    Location:
    Cumbria
    Ratings:
    +1
    Sorry Army Bloke but its you that's getting confused.....

    What is meant by digital display device is that it displays the image by a digital method LCD, unlike a crt which is analogue device (well sort of) a digital display device such as a LCD or DLP is incapable of showing an interlaced signal as it doesnt scan the frame to be shown, it shows the whole frame as one image. :rolleyes:

    You mention scaling, well scaling is not de-interlacing I never mentioned anything about your PJ scaling anything.... :nono:

    Finally the message that you refer to regarding what signal is being shown, refers to the signal the PJ is receiving at its inputs, thats why if you feed it a pal interlaced signal it says 576i/50 and if you use an iscan ultra or a pal prog dvd player then the PJ would say 576p/50, if you fed it an ntsc signal it would say 480(i or p)/60 etc...
     

Share This Page

Loading...