Xbox 360 lcd help

[leugeboy]

Hi,

I have a 32" Phlips LCD tv. It is new and has 2 HDMI inputs as well as the normal component. I am currently using component and using 720p as the display. Can anyone tell me which one is officially better? 1080i or 720p. I have noticed that 1080i is slightly sharper but not as good in games as 720p - 720p seems a bit smoother.

I have basically answered my own question but if anybody has any further insight I would be grateful. Also, has anyone heard when the HDMI cable is being released for Xbox360?

Many thanks for your help, Martin.

 

[Rolf N]

Use 720p. Interlaced video is a dirty hack (1080i transfers just 540 lines per frame) and needs to die out already.
There'll never be an HDMI cable for the current 360. Maybe there'll be one for a revised model somewhere down the road, but not for the one you bought.

 

[Hardknock]

What's the native resolution of your LCD? Also does your LCD have a VGA input? If so I would buy the VGA cable (better picture than component IMO) and lets you upscale DVDs. Then just pick the resolution that is closest to the native res on your set.

 

[Acert93]

Go with 720p. It is a progressive format and will represent 60fps games better.

 

[kyleb]

Use 720p. Interlaced video is a dirty hack (1080i transfers just 540 lines per frame) and needs to die out already.

1080i transfers 1080 lines per frame, that is exactly what the "1080" in "1080i" denotes and it is why 1080i commonly used in favor of 720p.

Neither is inherently though. 1080i allows for a little over double the pixels per frame compared to 720p, and 720p supports double the frames per second compared to 1080i. What differences that will make can depend greatly on what resolution and framerate a particular game is being rendered at along with how well a particular TV handles either of those signals. Beyond all that, the difference can come down to viewing conditions and personal opinion as well. So the only "officially better" choice here is whatever you find works best for you.

 

[Shifty Geezer]

Neither is inherently though. 1080i allows for a little over double the pixels per frame compared to 720p

At 30 frames per second. Above that (60 fps), the frames rendered in 1080i are fields, at half-height resolution. Or putting it another way, at 30 fps second, 720 provides 30 1280x720 images a second, and 1080i provides 30 1920x1080 images per second. At 60 fps, 720p provides 60 1280x720 images a second, and 1080i provides 60 1920x540 images per second.

 

[kyleb]

Above that (60 fps), the frames rendered in 1080i are fields, at half-height resolution.

I don't follow what you are saying here, an interlaced field by is definition half a frame. So while you can render 60 fields per second that is surely not the same thing as rendering progressive frames, be they half-height frames indented to be displayed anamorphically or otherwise. Besides, what 360 games do you know of that does anything of the sort? In every 360 game that I've seen the difference between 720p and 1080i on they have all been clearly rendered at the same resolution either way, with the only difference between the two outputs being the scaling and the interlacing to at 1080i throwing anything over 30fps out.

 

[LunchBox]

At 30 frames per second. Above that (60 fps), the frames rendered in 1080i are fields, at half-height resolution. Or putting it another way, at 30 fps second, 720 provides 30 1280x720 images a second, and 1080i provides 30 1920x1080 images per second. At 60 fps, 720p provides 60 1280x720 images a second, and 1080i provides 60 1920x540 images per second.

I'm confused

I've always thought 1080i will always transmit it in fields coz it's interlaced???

like 1080i @ 30 frames per second is 1980x540 @ 60 fields... please clarify it for me?????

 

[Shifty Geezer]

I've always thought 1080i will always transmit it in fields coz it's interlaced???
like 1080i @ 30 frames per second is 1980x540 @ 60 fields... please clarify it for me?????

That's right, and everything's rosy at 30 fps. When you get above that, you're not seeing full frames, where a frame is an image of 1920x1080. At 60 fps, the image on screen is being updated 60 times a second, but the redraw is drawing 60 1920x540 images per second.

The confusion only really comes from fields and frames, and frames per second, but the actually amount being drawn is straightforward.

I don't follow what you are saying here, an interlaced field by is definition half a frame. So while you can render 60 fields per second that is surely not the same thing as rendering progressive frames, be they half-height frames

Yes, a field is half the height of a frame in interlaced drawing, but at 30 fps you're combining two fields to draw a full-height frame. At 60 fps, with the image updating 60 times a second, you only have time to draw one field per image, which means that frame is half-height (or half-resolution, to be pedantic!).

For XB360 games, it's mostly a non-issue because most games are 30 fps. They're creating 30 images a second which the 1080i TV can render at 1920x1080. If a game is 60 fps 1080, it'll either be rendering half-height frames and outputting an interlaced signal, or rendering 60 full frames and outputting only half of that - which is okay if you're just upscaling 720p.

Because of this, at 720p, an XB360 can render 60 1280x720 images a second and have them displayed completely on a 720p TV. Or it can render 30 1920x1080 images a second and have them displayed completely on a 1080i TV. Or it can render 60 1920x540, or 1920x1080 images a second, and display 60 half-resolution images per second on the TV. When you total up the number of pixels drawn to the display (least confusing metric!), a 720p set gives you 55296000 pixels per second, and a 1080i set gives you 62208000 pixels

 

[LunchBox]

That's right, and everything's rosy at 30 fps. When you get above that, you're not seeing full frames, where a frame is an image of 1920x1080. At 60 fps, the image on screen is being updated 60 times a second, but the redraw is drawing 60 1920x540 images per second.

The confusion only really comes from fields and frames, and frames per second, but the actually amount being drawn is straightforward.

Thanks for clarifying man it totally helped!

 

[DuckThor Evil]

Thanks for clarifying man it totally helped!

Good for you, I'm still confused :smile:
I mean I see huge difference in 480i and p at 30 frames per second...

 

[kyleb]

That's right, and everything's rosy at 30 fps. When you get above that, you're not seeing full frames, where a frame is an image of 1920x1080. At 60 fps, the image on screen is being updated 60 times a second, but the redraw is drawing 60 1920x540 images per second.

But again, isn't that just rendering at a lower resolution to be displayed anamorphically? I don't understand how that could be considered interlaced rendering if the higher spatial resolution isn't accounted for.

Or it can render 30 1920x1080 images a second and have them displayed completely on a 1080i TV. Or it can render 60 1920x540...

Again, I haven't noticed anything like that on any of the 360 games I've compared the resolutions at. Do you know of any games that do this our are you just speaking hypothetically?

 

[Shifty Geezer]

Again, I haven't noticed anything like that on any of the 360 games I've compared the resolutions at. Do you know of any games that do this our are you just speaking hypothetically?

It was an exact response to your comment that 1080i offers twice the pixels, being pedantic about the displays. 1080i as a display format does not offer twice the number of pixel per second displayed as 720p. For actual display of XB360 games, it's a different ball-game because most games are rendering at 30 fps where 1080i does have the advantage, and/or are just upscaling 720p resolutions. In which case whether 1080i looks better than 720p or not is more to do with how your TV handles upscaling than anything!

 

[kyleb]

It was an exact response to your comment that 1080i offers twice the pixels, being pedantic about the displays. 1080i as a display format does not offer twice the number of pixel per second displayed as 720p.

I said "1080i allows for a little over double the pixels per frame compared to 720p", which it most certianly does.

For actual display of XB360 games, it's a different ball-game because most games are rendering at 30 fps where 1080i does have the advantage, and/or are just upscaling 720p resolutions.

And what about the few games that can offer 60fps, do you know of any that do what you suggested at 1080i?

 

[Shifty Geezer]

I said "1080i allows for a little over double the pixels per frame compared to 720p", which it most certianly does.

Yes, for static images and 30 fps, but not when the frame-rate is 60 fps... There's a word with two similar but different meanings here. 'Frame' for TVs is different from 'frame' in games. A 1080i TV frame is 1920x1080 pixels. But a 1/60th second frame rendered and output and displayed at 1080i from a console is 1920x540 pixels.

And what about the few games that can offer 60fps, do you know of any that do what you suggested at 1080i?

Not many. I'm only being pedantic about the idea of 1080i having double the resolution, because at higher framerates it doesn't, and I think people need to understand exactly what 1080i does offer. Otherwise there'll be crossed wires where people can read '1080i has about the same rendering requirements as 720p' and '1080i has doublt the resolution of 720p' and wonder what 1080p is all about when 1080i offers the best of all worlds.

I have 'no comment' on worth of particular resolutions for consoles!

 

[kyleb]

Yes, for static images and 30 fps, but not when the frame-rate is 60 fps... There's a word with two similar but different meanings here. 'Frame' for TVs is different from 'frame' in games. A 1080i TV frame is 1920x1080 pixels. But a 1/60th second frame rendered and output and displayed at 1080i from a console is 1920x540 pixels.


Not many.

I'm not asking if there are many, I"m asking what games do you know of that use these 1920x540 pixel "frames" as you claim?

 

[Shifty Geezer]

I'm not asking if there are many, I"m asking what games do you know of that use these 1920x540 pixel "frames" as you claim?

They don't. They may well be rendering at 720p and upscaling, or crazily rendering full 1080p frames. HOWEVER, when the console is rendering 1 frame every 60th of a second (60 frames per second), the TV is displaying 1920x540 pixels in that 1/60th of a second. The frame of that game is 1920x540 on the display. That's where the 1920x540 frame comes from - frame means what's visible on screen. Not 'what's the definiton of a frame resolution in 1080i'. And not 'what resolution is the frame being rendered'. So 1080i @ 60 fps doesn't have double the resolution per frame than 720p, when you consider a frame to be the image displayed on the screen for the period of 1/FPS, which is the only definition that matters when talking about console game resolutions on displays.

You pointed out 1080i has double the frame resolution and 720p has double the framerate, which is correct and based on definitions of frames. But a 1080i TV is capable of showing iamges at the same framerate of 720p, only at half it's maximum resolution. You aren't limited to 30 fps on 1080i.

 

[kyleb]

They don't. They may well be rendering at 720p and upscaling, or crazily rendering full 1080p frames. HOWEVER, when the console is rendering 1 frame every 60th of a second (60 frames per second), the TV is displaying 1920x540 pixels in that 1/60th of a second. The frame of that game is 1920x540 on the display. That's where the 1920x540 frame comes from - frame means what's visible on screen.

And again, every game I've checked the difference on, what has been visable on the sceeen at 1080i is 1920x1080 upscaled frames every 1/30th of a second, not 1920x540 pixels frames at 1/60th. The difference would be quite obvious, so I'm still curious, what game or games do you belive does what you claim?

 

[Shifty Geezer]

And again, every game I've checked the difference on, what has been visable on the sceeen at 1080i is 1920x1080 upscaled frames every 1/30th of a second, not 1920x540 pixels frames at 1/60th. The difference would be quite obvious, so I'm still curious, what game or games do you belive does what you claim?

I've said, none! And I'll leave it at that. My point was about the technical aspects of 1080i and displayed resolutions (in terms of pixels a second which are not confusing, unlike frames).

 

[kyleb]

I'd say pixels per second is a quite confusing metric to bring up here, as if you just go by that scale then 1080i is always a little better than 720p, when in fact the resolution of the fames and the framnerates of the two resolutions give each advatages and drawbacks compared to the other.