1. Join Now

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

PSM192 + scaler?

Discussion in 'TAG McLaren Audio Owners' Forum' started by PhilB1234, Sep 1, 2004.

  1. PhilB1234

    PhilB1234
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Since obtaining a HD projector (1280x720) and running my DVD32+PSM192 through it via DVI, I've noticed that the projector's internal scaling seems to have trouble working fast enough to keep up on rapid panning scenes.
    By comparing a native pixel image (720x576p@50Hz) to the scaled image (1280x720p@50Hz) I notice that the shapes and outlines are fairly well scaled, but there is colour banding in the colours and textures. Does this suggest that the projector's scaler isn't up to the job?
    Would an offboard scaler help?

    I've looked around and have seen a few options (bearing in mind the VSM2048 is out of my price range!):
    -iScan HD
    -Lumagen's new Vision HDP (are there any advantage's to going up to the ProHDP, other than case & cables?)
    -Crystallio (but twice the price of the iScan)

    Are there any others I've missed?

    Does anyone have any experience with Tag gear and any of these?

    Any comments on set-up or settings that might help me get the most from the current set-up?

    Any help or suggestions would be greatly appreciated!
     
  2. JohnMulcahy

    JohnMulcahy
    Member

    Joined:
    Jun 13, 2004
    Messages:
    181
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Aldershot
    Ratings:
    +20
    What kind of projector? Blurring from rapid motion is common on LCD projectors and also causes problems on some DLP projectors. Going in at native resolution is unlikely to help with this, but it may help the colour banding problem you mention, which could be a scaling deficiency especially if the scaling is done in the YPbPr space.

    It is almost certain that standalone de-interlacing and scaling would perform better than the projector's internal implementation, though you have the most difficult part covered already with the PSM. Besides the video processors you mentioned there are Vigatec, Key Digital, Faroudja etc but getting very costly. iScan HD, VisionDVI and Vision HDP look to be the main contenders for affordable processing/scaling. I've just bought a Vision HDP on the classifieds forum, will let you know how it performs once I get a chance to play with it - but firmware is still in beta.

    The iScan HD and Lumagen processors use the '504, as does PSM, though the iScan has some aspects of its implementation that help work around some deficiencies in the 504, whilst Lumagen are writing their own co-processing code and may move de-interlacing into their FPGA eventually (though maybe not for VisionDVI).

    If you are going DVI in and DVI out then Vision DVI or Vision HDP would look to be good options, Pro HDP should be usefully better for analogue sources and analogue projectors. Re the detailed differences between HDP and the Pro HDP, Jim Peterson of Lumagen posted this explanation in the middle of a monster 1300+ post thread on the AVS Forum, though in the context of an application using BNC analogue output rather than DVI:

    I haven't detailed these before, but here goes. This is some rather down in the hardware details, but they are differences that may be visible for SDI in and BNC out.

    - The processing and chips used are the same in the VisionHDP and the VisionPro HDP. This is what makes the comparison referenced to the original Vision/VisionPro the appropriate one.

    - Note that the VisionDVI does not use the same chips in some places, does not use the same processing in some parts of the pipeline and does not have as high a precision in the hardware for the calculations.

    - The VisionPro HDP has slightly better analog power supplies. The input and output are actually separate supplies in the VisionPro HDP, while the VisionHDP has one supply for both the input and output analog sections. This is less of an issue with SDI in, but the VisionPro supply is still a touch better. I cannot yet say if this really is going to be a noticable difference for SDI in and BNC out, but it should give the edge to the VisionPro HDP for analog in and analog out.

    - The BNC output on the VisionHDP is on a Daughter card while the BNC output of the VisionPro HDP is on the main board. So, the VisionHDP BNC output has an extra about 15mm of "not really 75 ohms" in the connector to the daughter-card that the VisionPro does not. This probably will be a (small) visible difference on a really good projector.

    - Not all inputs will be digital. The BNC's on the VisionPro HDP still give it the edge for the analog inputs.

    - I also like to point out that for the VisionPro HDP the 4 SD only inputs can be configured as 2 Component and 2 SVideo, or up to 4 SVideo. This gives it a significant edge for large systems.
     
  3. Gordon @ Convergent AV

    Gordon @ Convergent AV
    Distinguished Member AVForums Sponsor

    Joined:
    Jul 13, 2000
    Messages:
    13,999
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Living in Surrey, covering UK!
    Ratings:
    +2,803
  4. PhilB1234

    PhilB1234
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Hi John,
    The projector is a iVision HD, DLP using an original HD2 chip, rather than the newer HD2+.
    The interesting thing is that the shapes and borders of moving objects appear very controlled during pans (I'm thinking that shows the de-interlacing is doing a great job), but the colours within these lines are 'over-simplified', by that I mean they are reduced to just a handful of colours insead of the lare number used when the image was static. I hope that makes sense.

    If I were to use an offboard scaler and send in the scaled image at 1280x720p@50Hz would you expect the internal processing of the projector to be bypassed? Or is this difficult to predict? I'm hoping that scaler with decent processing power won't have these limitations and therefore the projector just has to do 'do what it's told' with a pixel-for-pixel image.

    I'd be keen to hear what you think of the HDP as that's the one I'm (currently) most likely to go for!
     
  5. GrahamMG

    GrahamMG
    Well-known Member

    Joined:
    May 8, 2004
    Messages:
    4,449
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    UK
    Ratings:
    +192
    Hi Phil.

    I wouldn't get bogged down in the difference between HD2 and HD2+, certianly from a motion point of view... ;)

    Bypassing the PJ's internal scaling is largely a matter of luck still, most units do still have a stab at buggering things up....DVI inputs are supposed to be the "most likely to succeed" method of bypassing internals but..... After a lot of DVI fiddling and many conversations with John regarding the VSM and best methods of connection, I settled on feeding the PJ processed RGBHV which gave less problems between PAL and NTSC sources and frankly looked better with no artifacts/jaggies/blocking/stuttering etc. I'm not saying all PJ's react the same though..... I will re-visit the DVI/HDMI connections one day probably after Gordon sets up Event3 and shows the various Lumagens/Leeza's etc. using DVI to feed DLP's.....Until then I'll stick with the VSM.....
     
  6. jbm007

    jbm007
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    John

    Now that you are on the forum. I have a Qualia 004 projector coming. It will be here next week. Are you familiar with it? I was just wondering if there would be any tricks to use in setting up the scaaler/av192 with the PJ. Will the scaler output 1080i 24fps to the projector?
     
  7. JohnMulcahy

    JohnMulcahy
    Member

    Joined:
    Jun 13, 2004
    Messages:
    181
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Aldershot
    Ratings:
    +20
    Hi jbm,

    I'm not familiar with the Qualia. When you say "scaler", which scaler do you mean? If you mean VSM2048, it only outputs progressive signals and its outout rate is locked to the input rate, so would be 50Hz or 60 (59.94)Hz only.
     
  8. JohnMulcahy

    JohnMulcahy
    Member

    Joined:
    Jun 13, 2004
    Messages:
    181
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Aldershot
    Ratings:
    +20
    jbm, I've looked at some of the info for the Qualia 004, very impressive! As the native res is reported as 1920x1080 it would be best to drive it with 1080p over DVI (no problem for VSM) if you were interested in comparing the results of external de-interlacing/scaling with directly connecting sources and relying on the projector's own processing. It claims 10-bit video processing and a liberal sprinkling of TLAs related to its de-interlacing, so connecting directly to it has to be worth trying, but some de-interlacing and scaling artefacts were reported in the Stereophile Ultimate AV review (http://www.guidetohometheater.com/videoprojectors/504sony/index.html). It would be best to leave the VSM's black level, white level, colour etc adjustments for your best source at the no-adjust settings and use the display's own adjustments to optimise the image, so that the (presumably) 10-bit projector processing resolution is used rather than the 8-bit resolution of the VSM's adjustments. The VSM adjustments should then be used for other sources as required to compensate for their individual characteristics.

    Looks like a great piece of kit, be sure to let us know how you get on with it.
     
  9. Gordon @ Convergent AV

    Gordon @ Convergent AV
    Distinguished Member AVForums Sponsor

    Joined:
    Jul 13, 2000
    Messages:
    13,999
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Living in Surrey, covering UK!
    Ratings:
    +2,803
    John,

    The Qualia doesn't accept 1080P in. It will accept 1080P24segmented frames. Which is why JBM asked. The Lumagen you just bought is currently being beta tested with some Qualia owners for just this specific purpose.

    Gordon
     
  10. jbm007

    jbm007
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Gordon

    How will your scaler improve what the vsm will not. I have heard that the Sony will eventually do 1080p. I think that is because that is what blu-ray will output. If I have problems with the vsm 2048 what would becoming a beta tester involove. I have a friend who is ISF certiied who calibrated the first Sony's that came out. He is coming to work with me. I am looking for the best set up combination I can. PM me if you have additional thoughts. I just hope the TAG scaler doe not cause issues after what I paid for it.


    Jim
     
  11. Gordon @ Convergent AV

    Gordon @ Convergent AV
    Distinguished Member AVForums Sponsor

    Joined:
    Jul 13, 2000
    Messages:
    13,999
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Living in Surrey, covering UK!
    Ratings:
    +2,803
    Hi Jim,

    Not my scaler...I'm just UK distributor. I've seen a Qualia and you've got a nice piece there...I#m jealous!

    By being able to remove the 2:3 sequencing of 24 frames per second film, turned in to 60 frames per second video you should get removal of motion judder artefacts inherent in your film based sources. Film based sources are, of course, films on TV and DVD/tape and also many tv programmes. Most shows on US TV (and UK for that matter) that are not studio based are recorded on film then tele-cine'd to video.

    The Lumagens have lots of other options that may allow you to to get a consistent nice image on all your sources.

    Your ISF guy should be able to speak with Lumagen direct to try and get you involved. If you email me I will happily put you in touch direct myself.

    Gordon

    I would add that the psm/vsm combo is very good at what it does, from what I've seen.
     

Share This Page

Loading...