RP HDTV Monitor

[mike909]

I have a Toshiba 51hx83
http://www.tacp.toshiba.com/televisions/product.asp?model=51hx83
It allows me to choose either 1080i, or 540p in it's on screen menu. The manual sais suggested scan rates are 1080i, 480p, 480i, 720p. I'm guessing this is just what it can 'accept'...i'm sure it can't display 720p. I have my dvd player connected via component, and will soon have a pc hooked up to it's dvi connection. To the best of my knowledge I am telling the dvd player to output a 480p signal, so if I want to view the 480p dvd should I choose 540p or 1080i from the tv's on screen menu? It's also possible that the tv upconverts everything to 1080i, but I can't tell from the manual. That's all for now (additional questions regarding the dvi input will probably follow)

[edDV]

That spec sheet is very "marketing' and gives no clue to true display resolution. I assume it is in the range of 800 to 1000 H and 600-1000 V. Since you have DVI with HDCP that dates your set to approx 2004.

First, DVD is 720x480 native and a DVD player can output that as 480i 59.94 fields pre second (interlaced mode) or 480p/59.94 frames per second (progressive mode).

HDTV for that type of set handles 480p in two ways; they alter scan rate to show true 720x480 progressive (all resolution in active 16:9 picture area at 59.94 frames per second) or they upscale to 1080i or some other resolution interlaced or progressive. Upscaling does not necessarily improve the image and it probably cuts refresh by half. Try it both ways if you have both modes. Make sure you evaluate motion.

I prefer native 480p/59.94 progressive myself on my CRT TV. Mileage will vary by TV.

If the TV only works for 1080i or 480i, it probably wants 480i from the DVD player so it can simply upscale at the same field rate.

[mike909]

Ed,
Yea, the manual is kind of marketing'ish too, but I'm not surprised. The set was bought late 2003. So...I guess theirs no real way to tell if the set can display 480p without upscaling. If the set does in fact upscale 480p to 1080i, than I mite as well output from the dvd player as 480i...if I understand it correctly. I guess it lets me choose 540p because it can display that without up/down scaling...what is 540p anyways? Probably some form of the HDTV spec has 540p. Regarding the dvi-d input it sais in the manual that it "will accept and display 480i,480p and 720p picture signals". This has to be wrong, I doubt it can display 720p. Also, it has a 'cinema mode' which when set to 'film' performs the 3:2 pulldown if a dvd player is connected to a component or dvd input (which it is..component).

[mike909]

Ok, just realized something.... according to the manual, that on screen menu lets me choose the display format for 480p signal source only. it sais I can use this feature to convert a 480p signal to 540p or 1080i. it sais signals other than 480p are automatically converted to 1080i. it also sais if you notice flicker in a 480p image try setting the display format feature to 540p. SO...being their is no selection in the menu for displaying 480p AS 480p (can only choose 540p or 1080i) can't we determine that it is not possible to display 480p? The way I read it is basically....EVERYTHING except 480p signal source is converted to 1080i, and 480p signal source has the ability to be displayed as 540p or 1080i...and that's it. So, basically I have only 2 practical choices. 1) output a 480p signal from dvd player and have tv upscale to 540p, or 2) turn off progressive output on dvdplayer and output 480i signal and let the tv upscale to 1080i. Is that how you understand it?
EDIT: On a side note...is there a utility disk or something that can help me configure my display..as opposed to replaying some movie scene over and over again...looking for quality differences? I.e. some disk that has video material on it from 480p, 480i, 720p, 530p, 1080i, 1080p etc. etc. source.

[edDV]

Yea, the manual is kind of marketing'ish too, but I'm not surprised. The set was bought late 2003. So...I guess theirs no real way to tell if the set can display 480p without upscaling. If the set does in fact upscale 480p to 1080i, than I mite as well output from the dvd player as 480i...if I understand it correctly. I guess it lets me choose 540p because it can display that without up/down scaling...what is 540p anyways? Probably some form of the HDTV spec has 540p.

540p is a single field of 1080i. One field is tossed and the other is displayed as 540 progressive lines. Sometimes horizontal resolution is halved as well to produce a 960x540p representation of a 1080i input.

Regarding the dvi-d input it sais in the manual that it "will accept and display 480i,480p and 720p picture signals". This has to be wrong, I doubt it can display 720p

.

720p (1280x720) would be internally converted to 1080i (1920x1080) most likely, or maybe to 540p.

Also, it has a 'cinema mode' which when set to 'film' performs the 3:2 pulldown if a dvd player is connected to a component or dvd input (which it is..component).

3:2 pulldown removal (aka IVTC) is only done on 29.94 fps interlaced video. In this case on 480i or 1080i inputs. The circuit will analyze for repeating fields, determine the sequence and then delete redundant fields restoring a 23.976 frames per sec progressive (or interlace) stream when film based video is being displayed. The frames will be repeated in a 3:2:3:2 pattern and displayed at 59.94 frames per second (progressive) or reinterlaced for display depending on how that set works internally.

Ok, just realized something.... according to the manual, that on screen menu lets me choose the display format for 480p signal source only. it sais I can use this feature to convert a 480p signal to 540p or 1080i. it sais signals other than 480p are automatically converted to 1080i. it also sais if you notice flicker in a 480p image try setting the display format feature to 540p.

So it's beginning to look like 1080i, 540p (quarter 1080i) or 480i are your only options. Possibly 480p is being directly scaled to 540p.

SO...being their is no selection in the menu for displaying 480p AS 480p (can only choose 540p or 1080i) can't we determine that it is not possible to display 480p? The way I read it is basically....EVERYTHING except 480p signal source is converted to 1080i, and 480p signal source has the ability to be displayed as 540p or 1080i...and that's it.

Looks that way.

So, basically I have only 2 practical choices. 1) output a 480p signal from dvd player and have tv upscale to 540p, or 2) turn off progressive output on dvdplayer and output 480i signal and let the tv upscale to 1080i. Is that how you understand it?

Try both methods for 480p (i.e. 1080i or 540p), then compare that to 480i from the DVD player. In 480i mode, the "Cinema" 3:2 removal kicks in and then the image is somehow scaled and field repeated to display 1080i.

I predict the latter will be the best choice but try it and see.

EDIT: On a side note...is there a utility disk or something that can help me configure my display..as opposed to replaying some movie scene over and over again...looking for quality differences? I.e. some disk that has video material on it from 480p, 480i, 720p, 530p, 1080i, 1080p etc. etc. source.

no. Your only choices for DVD player output are 480i or 480p. There are scaling DVD players but that would only duplicate what is already in your TV, that is rescale 480i or 480p to 1080i.

PS: HDTV sets like that also scale analog sources to 1080i and the cinema mode probably works for broadcast NTSC and VHS as well. It may not work as well as it does from a 480i DVD player because of higher noise levels.

[mike909]

Thanks Ed,
and yes...every source other than 480p is upscaled on this set to 1080i. I will give the 3 different possible options a try....but it would seem to make the most sense that output from the dvd player as 480i would look the best on this set.
EDIT: kind of funny that you pay (or at least used to pay) additional for a 'progressive scan' dvd player, but it's useless if your TV can't display it 'natively'.

[FulciLives]

This Saturday I am having a Hitachi 51" 16x9 HDTV CRT RP TV delivered. I looked at the manual and it does say it can do 540p or 1080i. It can handle just about any input but only displays 540p or 1080i. The model number is 51F710A

Right now I have a progressive scan DVD player but I am guessing I should just output 480i over the component video cables?

Hopefully by the end of January I will have enough saved up for the OPPO upconversion DVD player. I know it is excellent quality and I do need region free and PAL to NTSC conversion.

But for now I only have a Cyberhome CH-DVD 500 model DVD player which has no DVI or HDMI ... just the usual composite, S-video and component type outputs.

- John "FulciLives" Coleman

P.S.
I just noticed in my manuel (downloaded PDF version as I don't have the TV just yet) the following:

Under VIDEO adjustments (which you adjust contrast and brightness etc.) is the option VIRTUAL HD which allows you to choose 1080i or 540p but it comes with the following note: "VIRTUAL HD is not available (grayed out) in Digital Channels, 1080i input, HDMI and componets"

So I guess if I input 480i via component video it will do whatever it does (not clear if it does 540p or 1080i but obviously it does one or the other without the ability to choose).

[edDV]

It will take some testing to see which type of interface produces the best image from the different sources.

Analog NTSC (or PAL) inputs will probably look best upscaled by the TV to 1080i. Mike909's Toshiba has the cinema option that will allow "film" sources to be realtime IVTC'd and displayed at 540P. Automatic modes could switch the set to 540p when telecine sources are detected* but normal broadcast TV has rapid intercuts of pure interlace and "film" (e.g. news to commercials and back) so the set would need to do this smoothly.

Pure interlace source conversion to 540P will probably have deinterlacer motion issues.

The TV sets probably have various ways to play a DVD. 480i in would be treated like analog above and may auto switch from 1080i to 540p based on "telecine" sequence detection.

A 480p connection would probably be upscaled by the TV to 540P.

A DVD player scaled input over HDMI would trigger HDTV modes. I would bet 720P gets in downscaled to 540p and 1080i in gets displayed as is.

I would think a movie type progressive DVD would look best interfaced 480P and simply upscaled to 540P in the TV.

720P interface would first require the DVD player to upscale followed by a downscale to 540P in the TV.

I'm just speculating. All of these modes should be observed and the viewer can choose what looks best.

* 25 fps PAL sets would detect progressive "film" sources by analyzing field pairs for temporal motion. No motion = progressive.

[mike909]

My picture from DVD's seems to look better when outputting 480i and letting the TV upscale to 1080i, than when ouputting 480p and choosing either 540p or 1080i. If I ouput 480p I can choose on the TV whether to upscale to 1080i or 540P.
Perhaps my eyes are not trained enough, but all in all, I am not even sure if I can tell the difference between either of the 3 choices.

[edDV]

All that matters is which path looks best to you.