HDTV Video standards, or lack there of

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Hoping someone migt be able to help me out here...

I have a CRT rear projection TV which is supposed to handle 720p & 1080i
standards via Component video input & up until now no problems. My HD STB
works fine with the TV, set on either 720p or 1080i output. Connecting a PC
to the set however is a different story. Video card is an NVidia 7600GT
(with component video output obviously) and set to either 720p or 1080i I
have some serious sync issues.

Now am I under the wrong impression here or is a standard supposed to be a
standard or a rough approximation of something that should work. Not only
that but I haven't managed as yet to find any such "standard" reference to
1080i or 720p via component video, Levels, sync pulse timing etc.

I'm pulling my hair out over the bloody thing, I'm pretty sure not everybody
would have to look at the signal with a CRO to find out what's going on
(which is what I was planning to do, comparing to the output of the STB,
handheld Oscilliscope I have tried with so far is pointless though :))

And don't suggest buying a plasma or LCD TV either....not interested, I
prefer having something that I can repair, and has a superior picture :)


James



Re: HDTV Video standards, or lack there of



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Hi,
maybe the pertinent word there is that your tv is "supposed" to be...?

Anyway, perhaps you should check the specs of the tv and video card as to
whether its pal ntsc or secam? and whether the video card is outputting 50hz
frames?

maybe worth trying non progressive on 720 too?

or perhaps it's the resoultion you're running the screen at?

don't know too much about hooking tvs to pcs but the above seem the most
obvious areas to look at.

Have fun

Greg




Re: HDTV Video standards, or lack there of



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Works fine with 1080i output from HD STB

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CRT sets dont have fixed "resolutions" though, its all about the bandwidth
of the circuitry isn't it, technically the 1080i standard is 1920 x 1080
interlaced, but really I could change that to anything x 1080 interlaced and
achieve similar results, as there are no "fixed" number of pixels in each
line, as it's an analogue signal being fed to the thing. After mucking
around a little earlier today I did actually get it to sync in 1920 x 1080i
but with some weird coloured streaking. Ah well, keep playing around with it
until I get frustrated enough to put the lot on Ebay I guess :)

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Hi,
I meant the resolution of the pc screen. ie is the dvi output a fixed res or
is it dependant on what the vga res is?

Greg



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Not DVI, Component Video, and as for the PC screen resolution not being
independant, thats not a problem because there is no other monitor. Got ya
thinking now haven't I....No I'm not good enough to be able to change
settings without seeing the display...using VNC instead :)

James




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Well they do have a maximum number of 'lines', which is analogous in one
sense.  And a max bandwidth which is analogous in the other sense.

geoff



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I've heard 100Hz vertical rate mentioned, are you complying with that
possibly the tv wants sync on green, got that?

--

Bye.
   Jasen

Re: HDTV Video standards, or lack there of


  I have a hitachi CRT WS rear pro.

i connect my pc to it using componant output from my 6600LE nvidia card.

I found that the screen will happily sync and show what ever res my pc
will send out up to whateverX1080 i got it up to 2048x1080 and it looks
  very sexy. if you are getting bad colouring,  you may6 have mismatched
impedence on your cables. try another cable set.

maybe, your tv is running the componant input as RGB insstead of YUV. go
in to your tv input settings and change its references.

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Well thats good that it works for you but what about me? Maybe I should go
to Hardly Normal and buy a set of $200+ monster cables....OK you know I'm
only kidding :) The chroma problem had crossed my mind as being an impedence
issue as the cable I scrounged up is actually an old AV cable, using the
75ohm for the Y and the shielded audio cable for the Pb Pr. Unlikely to
explain the sync issues though. What vert & horiz scan frequencies are you
using? or are you just going with the driver defaults? If you did any custom
timing settings with powerstrip or the like it would be great if you could
post them here.

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To the best of my knowledge the inputs are Component only, not RGB, I really
have to get a service manual from HCSD, because the specs in the user manual
tell me SFA. All I know is when it does get a signal it recognises I get a
nice loud relay click and a picture :) otherwise when the signal is out of
sync it just greats me with "Incompatible mode" or something to that effect.
I'm not going to have another look tonight because I dont know how well
those fresnel lenses stand up to my fist :)

James



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Ah yes, the old Fresnel fist percussive maintenance.
An expert is needed. Patience is needed. Sounds like a bakery.
You need to learn patience and to know not all software is up to the
promises, and needs to be updated. Also Aldi are selling some fairly
good video cables at around 10 bucks for your info.

Re: HDTV Video standards, or lack there of


try a different cable, grab a couple pair of audio cables (so all cables
are the same impedence and short)

my tele can do 100hz or under which means it supports multi sync modes.
yours may or may not handle 50hz, 60hz and 100hz. what you can to is go
in to your nview settings and set the refresh rate to 60hz and try that.

as i was saying with mine, the 3 rca connectors used for YUV will also
run in R sG B.

one trick i used was connect the tele to the card and remove your
monitor and then reboot your machine (only tv connected) and you should
see your bios startup screen + the rest of the boot process. if you do
and then it all turns to shit when windows commences boot, you need to
hit F8 and select "enable vga mode" from the XP boot menu then force 60Hz.

i never used any special settings, the card and drivers did all the
work. i did have to play around with resolutions tho. try 1280x960 as
this is a 16:9 resolution. your nview settings will allow 800x480 as well.

James wrote:
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