720p video on a 1080p TV, and vice versa?

[sldvd]

How would a 1080p video look on a 720p TV? Would it look exactly the same as it would if the video were recorded in 720p, or would it be worse?

What about a 720p video on a 1080p TV? Would there be a 1-to-1 pixel mapping, so that there's a black border around the video? Or does the video get stretched out to fit the TV? I imagine it wouldn't look so good if that's the case.

[redwudz]

I'm no expert, but I would guess it would be downscaled or upscaled by the TV to fit the screen. How that looks depends on the circuitry in the TV. But I've never noticed any serious quality loss either way.

[Bonie81]

i hv all branded HD TV / BD player and sound system.
i do not feel much difference in DVD-SD, 720 HD or 1080 HD except video sharpness (which comes from higher bit rate naturally), plus additional DTS Audio track in case of BD. Some original DVDs have DTS too!

some original DVD-SD (AR: 16:9, 2CH AC-3) automatically unconverted to HD 5.1ch AC-3 to fill 16:9 big screen by hardware circuitry. some original DVDs (not downloaded stuff) give almost same sharp picture quality as BD, as well, very hard to notice difference. Many times I get original DVDs and BDs for very cheap in local retailers deals where exchange with same title is possible. just in case if it is scratched.

But, i am not a hardware expert either.

[v491138]

My TV only does 1080i and when fed 1080p it simply says unsupported format.
When fed 720p, it simply switches to that mode.
My conclusion is that if you fed 1080p to a TV that could only do 720p, it would simply do the same as mine does.
That is also based on my experience with computer monitors dating back to green screens <G>.
As far as HD recception goes, my TV simply works. I don't know what it does, but I got HD both on cable and over the air.
Or maybe it was simply widescreen though the signals were touted as HD by the broadcasters with little on screen logos and other references to their signal being HD.

[jagabo]

You need to separate what the TV displays vs. what it accepts as input. Many HDTVs won't accept 1080p as input, even many HDTVs that have 1080p screens. All HDTVs I know of accept 720p and 1080i input.

In general all HDTVs scale the incoming picture to the native resolution. Actually, slightly larger than the native resolution because they simulate overscan. Some 1080p HDTVs have a non-overscan mode where the 1920x1080 source is mapped pixel for pixel on the display.

Most 720p HDTVs don't actually have 1280x720 displays. They are usually more like 1366x768. An incoming 1080i or 1080p signal could potentially look a little better than an incoming 720p signal.

[jagabo]

i do not feel much difference in DVD-SD, 720 HD or 1080 HD except video sharpness (which comes from higher bit rate naturally)

No, it comes from the higher resolution (and the higher bitrate to support it).

[pirej]

Originally Posted by Bonie81
i do not feel much difference in DVD-SD, 720 HD or 1080 HD except video sharpness

I dont fill it too, but i can see a BIG difference between SD and GOOD HD (720 or 1080)

This are the supported format's on my HD-TV "37PFL5405H/12"

Supported Display Resolution
• Computer formats
Resolution Refresh rate
640 x 480 60Hz
800 x 600 60Hz
1024 x 768 60Hz
1280 x 768 60Hz
1280 x 1024 60Hz
1360 x 768 60Hz
1920 x 1080 60Hz

• Video formats
Resolution Refresh rate
480i 60Hz
480p 60Hz
576i 50Hz
576p 50Hz
720p 50, 60Hz
1080i 50, 60Hz
1080p 24, 25, 30, 50, 60Hz

And i guess it does support 1080p input, but not if it's coming from the PC(hdmi)??
Maybe it support's 1080p only from plugged in usb, or dvd/bd player???

[v491138]

You need to separate what the TV displays vs. what it accepts as input. Many HDTVs won't accept 1080p as input, even many HDTVs that have 1080p screens. All HDTVs I know of accept 720p and 1080i input.

In general all HDTVs scale the incoming picture to the native resolution. Actually, slightly larger than the native resolution because they simulate overscan. Some 1080p HDTVs have a non-overscan mode where the 1920x1080 source is mapped pixel for pixel on the display.

Most 720p HDTVs don't actually have 1280x720 displays. They are usually more like 1366x768. An incoming 1080i or 1080p signal could potentially look a little better than an incoming 720p signal.

No confusion on my part on this one. I do not care about the display other than given an input, I get one (in this case). The original question was predicated on the input. On a TV or other display that only goes to 720p and you try to input a 1080p signal, what would you get? I'd say nothing just as I do now. And just as obviously on a TV or other display that does accept a higher resolution signal,, I'd expect to see some representation that is either a real 720p image or a 1080p approximatin when feeding that higher resolution device with the low 720p signal. As for the relative qualities, it is clear you know something of that and likely more than I remember of what I've read about it. But that doesn't change the truth in what I've said since the question was based on input and that is how I looked at it. The actual display resolution and how the device processes the input in order to fit it to the native resolution of the display simply isn't involved in the question (at least as I understood it).

[jagabo]

Every 720p HDTV will downscale 1080i to 720p. If it accepts 1080p input it will downscale it to 720p. Conversely, any 1080p HDTV will upscale 720p input to 1080p. The quality of the scaling can vary.

HDTV behavior with other sizes varies. Some won't display anything at all. Some will center the image (assuming a computer is the source so you want a pixel for pixel display), some will scale.

Computer monitors can be different. Cheap 720p displays may not accept 1080i or 1080p input. Some high resolution monitors will display low resolution inputs at the original resolution with black borders to fill the screen. Some will scale instead.

[v491138]

Originally Posted by Bonie81
i do not feel much difference in DVD-SD, 720 HD or 1080 HD except video sharpness

I dont fill it too, but i can see a BIG difference between SD and GOOD HD (720 or 1080)

This are the supported format's on my HD-TV &quot;37PFL5405H/12&quot;

Supported Display Resolution
• Computer formats
Resolution Refresh rate
640 x 480 60Hz
800 x 600 60Hz
1024 x 768 60Hz
1280 x 768 60Hz
1280 x 1024 60Hz
1360 x 768 60Hz
1920 x 1080 60Hz

• Video formats
Resolution Refresh rate
480i 60Hz
480p 60Hz
576i 50Hz
576p 50Hz
720p 50, 60Hz
1080i 50, 60Hz
1080p 24, 25, 30, 50, 60Hz

And i guess it does support 1080p input, but not if it's coming from the PC(hdmi)??
Maybe it support's 1080p only from plugged in usb, or dvd/bd player???

Not quite. That is what HDMI is all about. That is exactly the input that will display that 1080p signal IF it is at one of those refresh rates. When the TV is connected to my laptop via HDMI, my laptop sees the full native resolution of the TV. very cool for movies. I'd say you 3have a standard VGA type computer input on that TV for which the computer resolutions are valid. Note that they are (with 3 exceptions) 4:3 and not widescreen. Your HDMI input should give your computer full access to the &quot;TV&quot; resolutions.

[pirej]

And probably 1080p video will look better on 720pHDTV then 720p video on 1080p HDTV.

Originally Posted by sldvd
What about a 720p video on a 1080p TV? Would there be a 1-to-1 pixel mapping, so that there's a black border around the video? Or does the video get stretched out to fit the TV? I imagine it wouldn't look so good if that's the case.

There are no borders, the video is being upscaled to fit the screen, and it looks good

[pirej]

Not quite. That is what HDMI is all about. That is exactly the input that will display that 1080p signal IF it is at one of those refresh rates. When the TV is connected to my laptop via HDMI, my laptop sees the full native resolution of the TV. very cool for movies. I'd say you have a standard VGA type computer input on that TV for which the computer resolutions are valid. Note that they are 4:3 and not widescreen. Your HDMI input should give your computer full access to the "TV" resolutions.

No, i have a Full-HD(1920 x 1080) PC Monitor, and its connected to the TV using HDMI, but i have never played 1080p video on it, that's why i dont know if it would play it .
I have a small Sony camera that records AVCHD in 1080-50i, and the videos play perfectly(great deinterlacing) on the TV if i play it from a pluged in usb, and if i play it from the PC... then there is no deinterlacing from the TV, it just plays what it gets from the PC.

[v491138]

i hv all branded HD TV / BD player and sound system.
i do not feel much difference in DVD-SD, 720 HD or 1080 HD except video sharpness (which comes from higher bit rate naturally), plus additional DTS Audio track in case of BD. Some original DVDs have DTS too!

some original DVD-SD (AR: 16:9, 2CH AC-3) automatically unconverted to HD 5.1ch AC-3 to fill 16:9 big screen by hardware circuitry. some original DVDs (not downloaded stuff) give almost same sharp picture quality as BD, as well, very hard to notice difference. Many times I get original DVDs and BDs for very cheap in local retailers deals where exchange with same title is possible. just in case if it is scratched.

But, i am not a hardware expert either.

One small detail here. I understand that you will not see any real difference between 720 vs 1080 until you view them on at least a 32 inch screen. I'd say 40 myself. And yes, I know that today that is usually thy case, but I sit no more than 18 inches from my 19 inch widescreen, not 16:9.

[v491138]

Not quite. That is what HDMI is all about. That is exactly the input that will display that 1080p signal IF it is at one of those refresh rates. When the TV is connected to my laptop via HDMI, my laptop sees the full native resolution of the TV. very cool for movies. I'd say you have a standard VGA type computer input on that TV for which the computer resolutions are valid. Note that they are 4:3 and not widescreen. Your HDMI input should give your computer full access to the &quot;TV&quot; resolutions.

No, i have a Full-HD(1920 x 1080) PC Monitor, and its connected to the TV using HDMI, but i have never played 1080p video on it, that's why i dont know if it would play it .
I have a small Sony camera that records AVCHD in 1080-50i, and the videos play perfectly(great deinterlacing) on the TV if i play it from a pluged in usb, and if i play it from the PC... then there is no deinterlacing from the TV, it just plays what it gets from the PC.

"no", you've got it. More than I "got" it. Might point exactly about those 3 exceptions. And that you do get it via HDMI is my point. Nope, you have it and didn't quite see it and I didn't quite follow your lead. Thanks

[jagabo]

One small detail here. I understand that you will not see any real difference between 720 vs 1080 until you view them on at least a 32 inch screen. I'd say 40 myself.

It depends on how far away you sit. 2 feet away from a 24" monitor and you'll easily see the difference between a good 720p source and a good 1080p source. 10 feet away from a 32" HDTV and you won't see a difference.

[v491138]

One small detail here. I understand that you will not see any real difference between 720 vs 1080 until you view them on at least a 32 inch screen. I'd say 40 myself.

It depends on how far away you sit. 2 feet away from a 24&quot; monitor and you'll easily see the difference between a good 720p source and a good 1080p source. 10 feet away from a 32&quot; HDTV and you won't see a difference.

Did I or did I not say that I sit roughly 18&quot; from my 19&quot; widescreen (not 16:9)? (and just how does one get a &quot;smiley&quot; in here?) Otherwise, YOU are CORRECT. Also, I might note that I do not wear glasses, but have had the lens in my eyes replaced and I'm 63. So NONE of my skills etc are anything like what they once were . Thankis.