TV tech

[haertig]

Originally Posted by JSWolf

Amazon did botch the PW4 and I do feel sorry for anyone how bought one. The screen was the problem. How they did it when they made it flush made the screen muddy and less contrast.

I think people here sometimes obsess over resolution and contrast. Yes, it's nice to have, but I'm not going to throw a less-then-300-dpi device into the trash can. Or demand the latest in contrast technology before I'll agree to read a book.

My home theater setup is 4K. And 4K movies look good on it. Especially when you add HDR to the mix (that actually makes a much bigger difference than the 4K). But 1080 movies look good as well. And so do 720 movies. And I still watch DVDs on it too (gasp, not even Bluray - although I have that capability - but plain old regular DVDs). What are those, 480 I think? They are fine. Can I tell a difference? Of course, if I walk up close to the screen and examine the pixels. Does it make any difference in enjoyment of a movie? No.

I read books to enjoy them. Not to microscopically examine the pixels on my eReader.

[Quoth]

Originally Posted by haertig

but plain old regular DVDs). What are those, 480 I think? They are fine. Can I tell a difference? Of course, if I walk up close to the screen and examine the pixels. Does it make any difference in enjoyment of a movie? No.

I read books to enjoy them. Not to microscopically examine the pixels on my eReader.

Europe and some other places use 576 line DVDs. Also for NTSC you need Progressive and suitable source DVDs or else not only are they only 480 line, but have 3:2 pull down artefacts if the 24 fps film was converted to NTSC video before encoding. PAL DVD quality is unaffected by progressive or not.

I still watch the odd VHS (about 480 line NTSC and 576 lines PAL /SECAM) only about 250 horizontal resolution unless a local S-Video recording (nearly 400). NTSC analogue video/VHS is seriously poorer colour than PAL too, but it was about 16 years earlier! My older HDTVs had component, SCART (RGB or composite), Y/C and composite, VGA and 4x HDMI. Latest TV only has 2 x HDMI, so I have a Yamaha Home Theatre (Theater) with 4x HDMI in and some adaptors for VGA, component, S-Video(=Y/C) and composite. Don't need the RGB one because the Philips BD player plays all regions DVD (but only local BD).

I remember the rubbish UK 405 lines (378 visible lines, 625 = 576 and 525 = 480, hence VGA was 480 lines). It rand from 1936 to 1985 with a 1939 to 1946 gap. Political nonsense restarting it in 1946 for only 300 TV sets instead of USA 525 with 50 instead of 60, or waiting 2 years for 625. The USA and several European countries used 441 lines before 625. After WWII Europe used 625, except for France and Belgium (819). The 1080 line visible HD is based on Japan NHK 1125 line hybrid HD (1080 visible). HD is a bigger mess of standards than Analogue TV.


It's annoying when a BBC or European DVD recording is mysteriously only "region 0" which is usually NTSC.

[Aleron Ives]

Originally Posted by Quoth

Also for NTSC you need Progressive and suitable source DVDs or else not only are they only 480 line, but have 3:2 pull down artefacts if the 24 fps film was converted to NTSC video before encoding. PAL DVD quality is unaffected by progressive or not.

The problem with film content on PAL DVD is that it's often just sped up to 25 fps, so not only does the movie become shorter, but sometimes the audio isn't even pitch corrected. It's possible to IVTC NTSC DVDs to restore the progressive frames of the film content, and the gap between 24 fps and 2400/1001 fps is much smaller than the gap between 24 and 25 fps.

[JSWolf]

Originally Posted by Aleron Ives

The problem with film content on PAL DVD is that it's often just sped up to 25 fps, so not only does the movie become shorter, but sometimes the audio isn't even pitch corrected. It's possible to IVTC NTSC DVDs to restore the progressive frames of the film content, and the gap between 24 fps and 2400/1001 fps is much smaller than the gap between 24 and 25 fps.

But with HD Blu-Ray and UHD Blu-Ray, they are frame correct. A lot of UHD Blu-Ray are region free. So you get the 4k, HDR, correct frame rate, and no region restriction. It's a win-win.

[Aleron Ives]

Originally Posted by JSWolf

But with HD Blu-Ray and UHD Blu-Ray, they are frame correct. A lot of UHD Blu-Ray are region free. So you get the 4k, HDR, correct frame rate, and no region restriction. It's a win-win.

Of course, you need a UHD player and UHD TV for the UHD Blu-ray to be worth anything. Blu-ray is also quite a bit more trouble if you want to rip your movies for things like NAS access.

[haertig]

My local library also has a ton of DVDs you can check out for free. But no Blurays that I am aware of. Some movies are not worth buying (some aren't even worth the cost to stream them). Older and less popular titles are not always available for streaming, and purchase (if you can find that) can sometimes get expensive. Libraries to the rescue! (at least some of the time)

p.s. - Example: Zorro the Gay Blade with George Hamilton, Lauren Hutton, Brenda Vaccaro, Ron Leibman... Funny movie. Older. Politically incorrect these days, so probably "canceled". I haven't seen it streamable. You can buy it, but it's like $10. Our library has it on DVD though.

[JSWolf]

Originally Posted by Aleron Ives

Of course, you need a UHD player and UHD TV for the UHD Blu-ray to be worth anything. Blu-ray is also quite a bit more trouble if you want to rip your movies for things like NAS access.

You do not need a UHD TV. You can get a good UHD Blu-Ray player such as the Panasonic DP-UB820-K which allows you to play UHD Blu-Ray on an HDTV. It downscales to HD and converts HDR to SDR. Then when you do finally get a UHD TV, you will have your library of UHD Blu-Ray. Also, a number of UHD Blu-Ray come with the HD version.

It means that when you do finally get a UHD TV, you are all set and ready to go instead of stuck with an HD Blu-Ray player and HD Blu-Ray.

I've tested this on my Panasonic and it dowsclaes and converts HDR to SDR rather well.

[haertig]

Originally Posted by Aleron Ives

Of course it's possible to downscale UHD, but there's no benefit to buying the UHD version when your equipment can't handle the output. I have no intention of ever buying a UHD TV, as even 1080p is overkill for my viewing conditions.

What you will probably find, as I did, is that a 1080p set is not going to have the newest features on it. If you want better features, more connections, newer innovations (HDR, etc.) then you're probably going to have to buy a 4K set to get them. Even if your seating distance and screen size would not show you any benefit for 4K alone (resolution-wise). I can tell you, that HDR is a vast improvement at any seating distance. It makes more of an impact than moving from 1080p to 4K, even when your seating distance is close enough that 4K actually makes a difference. BTW, HDR does not require 4K, you can have it on 1080 too. But finding a 1080 set that supports it may not be easy, and if you do find that set, it will probably cost as much as a 4K set anyway.

And currently, 4K sets do not cost a whole lot more than 1080 sets. They certainly DID, back when 4K first came out. But they don't now. You're kind of cutting off your nose to spite your face by sticking to purchases of older technology. Once the newer technologies become mainstream and drop in price, there's not much reason to buy old stuff. Once the price advantage has evaporated, what benefits are there? I can certainly see not replacing older stuff that is functioning fine and meeting your needs. I wouldn't replace that myself (says the guy still reading on a PW3). But once the old stuff starts deteriorating or it no longer meets your needs, treat yourself to some newer stuff if it's not going to cost you any more than re-buying old stuff.

[Aleron Ives]

Originally Posted by ZodWallop

Isn't Carta and Carta HD the same thing? The resolution makes it HD, but it's not like it's a different generation of screen, is it?

I'm pretty sure that's right. Carta HD just means 300 PPI using Carta, instead of < 300 PPI.

Originally Posted by haertig

If you want better features, more connections, newer innovations (HDR, etc.) then you're probably going to have to buy a 4K set to get them.

You're kind of cutting off your nose to spite your face by sticking to purchases of older technology. Once the newer technologies become mainstream and drop in price, there's not much reason to buy old stuff. Once the price advantage has evaporated, what benefits are there?

Well, I don't really care about the "innovations" in the video sector. Yes, I'm sure HDR does look a bit better than SDR, but is it really that much of a leap? I normally use a TN monitor for my PC. I can tell that an IPS monitor looks better when they're side by side, but I find the TN monitor perfectly usable when I'm not comparing them. I suspect HDR and SDR are the same way.

As for the benefits of older tech, the weak DRM on DVD means that you actually do own the movies you bought. BD DRM is significantly more draconian, and UHD BD is even worse still. I'm leery of investing in a format that may cease to work in the future, because a server somewhere is no longer online. I'm not even 100% sold on BD yet, so I'm certainly not going to jump into UHD BD.

[haertig]

Originally Posted by Aleron Ives

Yes, I'm sure HDR does look a bit better than SDR, but is it really that much of a leap?

I personally think it's more than "a bit better", but everyone would have to judge for themselves:

[Aleron Ives]

Uhh... maybe I'm crazy, but that's not even the same picture, so I don't think it really proves anything.

[haertig]

Originally Posted by Aleron Ives

Uhh... maybe I'm crazy, but that's not even the same picture, so I don't think it really proves anything.

Of course it's not the same picture. One was taken with an SDR camera, and the other was taken with an HDR camera standing next to the first camera. HDR is not simple post-processing that can be applied to an existing image. It has to be captured in the image from the start. Starting with the camera. And then it has to be continued through any post-processing, and finally displayed on a device that is capable of handling the HDR info.

I think it is somewhat akin to taking multiple captures of an image, each using different exposure settings, and then combining those images taking the best from each and coming up with a composite. Something like that, in basic terms.

p.s. - The above description is my understanding of the process as it was originally done with still photos. I believe the techniques to come up with an HDR output in video are implemented differently. For one, I believe the control information in an HDR video stream instructs the backlighting of the display device to change for different parts of the image. But just like in regular photography, if parts of the image are blown out to pure white, or so underexposed that they are pure black, no amount of processing is going to bring detail to areas that simply have none. Hence, you need a camera (still or video) that captures different parts of the image at different exposures. I don't think this can be done with one single capture, but I'm not an expert on the implementation. I just like the results!

[haertig]

p.p.s. - My TV does HDR, however, it was one of the first that did it, and it does not display on the screen "Hey, you are looking at an HDR video stream" like the newer sets do. But you can tell the difference, and not by just eyeballing the result and declaring "it must be HDR because it looks so good". On TV sets, you can adjust the intensity of the backlight in settings. Normally you set that at far less than 100% intensity. I can't remember the exact number I have mine set at, but lets just say it was 65% for this discussion. You would never set your backlight at 100% intensity ... the resulting picture would be horrible. Anyway, when playing SDR content, I can go to settings while the film is playing and observe that my backlight intensity is 65%. That indicates SDR. But when I am playing HDR content, I can go to settings and I find my backlight has been turned up to 100%. This is because the control info in the HDR content subsequently instructs the backlight to alter its intensity for different parts of the image. As soon as the HDR content stops and things revert back to SDR, then I can observe in my settings that the backlight is once again set to 65%. This is how I can verify I am looking at HDR content objectively, not subjectively. Sometimes a scene in a movie is intentionally dark and low contrast, because that's the way the director wanted it. HDR does not automatically brighten that to make midnight look like noon. The control info in the HDR stream instructs the TV to display the parts it wants as "dark, and the viewer shouldn't be able to make out details". Because of this, you can't just look at any scene in any film and deduce, "This is HDR content". Some scenes you are not meant to be able to see well.

[JSWolf]

Originally Posted by Aleron Ives

Are there any good comparisons of 300 vs 212 PPI, or do you simply have to see it in person? I can't imagine settling for less crisp text unless the price difference was huge.

My Kobo Aura H2O is 265 DPI. I doubt most would know it wasn't 300DPI if they didn't know.

Of course it's possible to downscale UHD, but there's no benefit to buying the UHD version when your equipment can't handle the output. I have no intention of ever buying a UHD TV, as even 1080p is overkill for my viewing conditions. The UHD BD usually costs more, so I wouldn't waste my money on it.

Most TVs made these days are 4k TVs. So if you were to ever replace your TV, would you get a 4k TV or would you look for another HD TV?

[Aleron Ives]

Originally Posted by haertig

Of course it's not the same picture. One was taken with an SDR camera, and the other was taken with an HDR camera standing next to the first camera.

Ah, I assumed this was supposed to be a video frame taken from a UHD Blu-ray and its HD counterpart, and thus it should have been possible to grab the same frame number both times. My mistake.

Originally Posted by haertig

and finally displayed on a device that is capable of handling the HDR info.

This is a wrinkle I was afraid of. Since I'm looking at the image on a TN LCD, my understanding is it's impossible for me to see the true benefits of HDR, anyway.

Originally Posted by haertig

I think it is somewhat akin to taking multiple captures of an image, each using different exposure settings, and then combining those images taking the best from each and coming up with a composite.

I believe the techniques to come up with an HDR output in video are implemented differently.

Yes, HDR has nothing to do with creating a composite image. It has to do with how the image is stored. We usually think of digital images in terms of R G B values, but storing full RGB information requires way too much space for video. Instead, the video is transformed into chroma (colour) and luma (brightness) components. Since the human eye is much more sensitive to brightness than colour, the colour component is usually stored at quarter resolution, e.g. the luma is 1920x1080, but the chroma resolution is only 960x540. This is called chroma subsampling, of which 4:2:0 is the most common type.

The luma (Y) and chroma (UV) are commonly arranged in a planar format (meaning Y and UV are stored separately, rather than interleaved) called YV12. This is much more efficient than RGB, and the quality degradation is hardly noticeable, leading to a big compression efficiency increase, but there's a problem: how do you convert back to RGB, so you can actually display the image on your TV?

There are multiple standards for this, and this is where SDR vs HDR comes in. Regular Blu-ray uses Rec.709 to define the rules of the conversion, whereas UHD Blu-ray uses Rec.2100 for things like Dolby Vision. The main thing to note on each Wikipedia page is the spectrum area covered by the black triangle: Rec.2100 (and Rec.2020, which Rec.2100 was extended from) cover a much higher percentage of all possible visible colours than Rec.709 does by specifying different conversion formulas for how to move between YUV and RGB. Rec.2020 covers the same wide gamut as Rec.2100, but it doesn't support HDR.

As long as you record the original footage in HDR, you can convert to SDR by doing a YUV -> RGB conversion using Rec.2100, and then converting RGB -> YUV using Rec.709 (or Rec.601, if you want SD resolution).

The move from 8 bits per pixel to 10-12 bits per pixel is also somewhat relevant, but this is mostly useful from a compression perspective: the banding artifacts caused by using 8 bpp reduce compression so badly that using 10 bpp (4x more precision) actually improves compression, despite the need to represent more information.

Hopefully I haven't mucked this up too badly. Video encoding is a complex subject, and I'm only a hobbyist, not an expert.