1080i vs. 480p on HD Ready 4:3 TV

[ToxMox]

I just got a new 4:3 27" Panasonic HD Ready TV that has component in and supposedly supports 1080i and 480p. Today I received the Crescendo Systems TC2000 transcoder and I'm wondering what will get me a better result 480p or 1080i? I have an Nvidia based FX5200 card and I guess I'll have to use Powerstrip. I just don't want to break my new TV by doing something stupid and hopefully get the best result I can possibly get. Any help will be greatly appreciated. Thanks!

[David Lawrance]

Here's my simple-minded thinking...

You'll probably letterbox with 1080i, and on a 27" set, that will be a small pixture, indeed. If you're mostly watching regular TV programming, then 4x3 formatted programming will end up even smaller. Sure, you can stretch and crop, but why not just use the entire screen. 480p could be your better bet. David

[stanger89]

I'll dissagree, on the provision that you can make 1080i fill the screen, if you can go for that, otherwise stick with something that does fill the screen.

[jptaz]

I disagree with David and question why you think you need to send it one of its native resolutions.

I use the DVI input on my 32" Zenith that also supports 480P or 1080i natively, but I use 1280x720 on my FX5200 so no messing with PowerStrip.

When I used 480P the video looked horribly blocky. The 1280x720 (720P) signal gets converted by the TV to 1080i and looks great.

I don't know how powerful your computer is but think about how much work your computer will have to do to scale your 720x480 video to 1920x1080i, you might even be able to make a custom resolutiion with the lastest Nvidia drivers to dk 1920x540P, but I don't what this will look like.

Of course this all hinges on your TV having an aspect ration option. by default my TV is set to Set the aspect ratio based on the input, which as David correctlu points out would be letter boxed on a 4:3 TV. I change my aspect ratio to 4:3 when using SageTV.

EDIT: I see that Panasonic went Cheap and only actually accepts 640P or 1080i via component. I would recommend that you feed 1080i or 540P if that works. But I also see that there is an aspect mode so you can swith the 1080i signal to 4:3.

John

[ToxMox]

I really appreciate the tips so far.

From reading what has been posted so far I'd like to feed the TV 1080i via the transcoder converting VGA to Component.

Now I've been looking at the thread on AVS forum regarding the powerstrip timings etc and most of that documentation refers to people using a Radeon card. Since I'm using the FX5200 I am really confused on which setting to try.

Will I need powerstrip to definitely do this and if so what settings would you guys recommend?

[jptaz]

You might want to at least try playing with the settings in the latest Nvidia Drivers. I have heard that they have improved settings for HD.

John

[ToxMox]

What would be an appropriate resolution to try to get 1080i without frying the TV.

[jptaz]

I may be wrong here, but I do not think it is possible to fry the TV. If the signal that you send is not correct the display should just say no signal is available.

[stanger89]

Originally Posted by ToxMox

What would be an appropriate resolution to try to get 1080i without frying the TV.

1080i is 1920x1080i,
But the important thing it that the horizontal scan frequency be 33.75kHz, that there, is what tells the TV it's 1080i. What I would do is look in the nVidia CP, the newer drivers are supposed to have advanced/custom timing support, hopefully you'll be able to do it through there. What I'd look for is 1920x1080@30Hz.

[ToxMox]

I have no idea if it is possible but if I can get the nVidia CP to use a custom setting of 1920x1080@33.75Hz should I try that instead of 1920x1080@30Hz?

[stanger89]

That's 33.75kHz, it's horizontal scan rate not vertical refresh (30Hz).

I'm not sure how detailed the settings are in the nVidia CP, but if you can specify horizontal scan and vertical refresh rates, I'd try that, set them to 33.75kHz and 29.97Hz respectively.

Otherwise, if there's a 1920x1080@30Hz Interlaced preset it should be close.

[ToxMox]

Ok cool...thank you so much for the words of wisdom. I will hopefully try this out tonight.

[stanger89]

The only other comment I'll make is start at 640x480@60Hz, just to make sure everything's working. You might even want to make a keyboard shortcut so you can switch back if you get into an "out-of-sync" situation.

[ToxMox]

Gotcha. I was planning on using the vga pass through on the transcoder to hook up to a monitor during the setup procedure but wasn't looking forward to having to lug my old 60lb 20" hitachi into the living room.

[jptaz]

I have also found that using VNC is a good idea. If something goes wrong no matter what the refresh rate / resolution is you can usually go in and use VNC to make changes.

John

[ToxMox]

John, great suggestion! I will chuck UltraVNC on there and do that instead of lugging around the monitor

[ToxMox]

OK so I just tried some things with the nVidia drivers. The nVidia CP's custom resolutions seem to cover all the possibilities. When I use the 480p setting it works great. When I used the 1080i settings I ended up with the left and right edges of the windows desktop meeting in the middle of the TV with a thin black line going down the middle seperating them. Everything is basically shifted over half way if you get my drift. Is this a common issue? If so what did I do wrong?

[stanger89]

Hey, to satisfy my curiosity, could you post a screenshot of the custom resolution CP?

As for your shift issue, are there options for "porches" or "sync pulses" I'm thinking perhaps (wild, educated guess) that maybe your sync pulses are inverted, or the porches are off.

[ToxMox]

Here is a screencap of the advanced timings mode and the setting I'm trying for 1080i.

[stanger89]

That's very cool, looks like it covers 90% of what powerstrip does.

If you're still getting the image in the wrong place thing, try switching the Sync polarities. Or possibly the Horizontal porches.

Man I just want a new video card more and more