Why do HDTVs look so bad?

[Stephen Mann]

A lot depends on your source and what the metadata says. I can assure you, though, that practically no cable or satellite service is really sending HD. Technically, the FCC defines HD as anything better than NTSC 480-line, so when they say you are getting HD programs, they aren’t lying.

Steve Mann
MannMade Digital Video
http://www.mmdv.com

[Dave Haynie]

[Angelo Mike] “This isn’t a Vegas question, just something I’ve noticed while staying in hotels and at other people’s houses.
“

HDTV can look very good, but it depends on the material. Hotels are probably the worst place to look. Many hotels are using some kind of in-house video distribution system, often analog, rarely digital. Check it out… you probably have just a coax going into the television, most of the time. Unless they’re rebroadcasting ATSC or QAM (cable), you’re not getting HD at all. They may have what’s basically an in-house cable system… they’ll have a “head end” with a couple CATV or satellite tuners, the closed circuit channels for their own purposes, and a system that may just put this out over analog NTSC. The last few times I’ve stayed in a hotel, I had the ubiquitous 32″ HDTV, and some 16:9 channels, but nothing in HD.

Newer systems will have HD, but they always upgrade the TVs first. Given the power requirements, some hotels look at swapping out CRTs for LCD/LED TVs as a medium-term savings, even if the don’t change the content.

It’s also pretty amazingly true that many home users have HDTVs with no HD content. Some people buy the HDTV and hook it right up where the SDTV was. Or they’re just uninformed about HD, and maybe a little blind. I was skeptical about this, but last spring, one of my sisters got a big LCD TV. She’s a PhD, but not very technical… a Mac/iPhone user, you know the type 🙂

So my soon-to-be ex brother-in-law had set up the system. The BD player was correctly attached, via an HDMI cable (the only option), but they had a cable TV box, HD-capable, hooked in via the old evil yellow RCA-ended CVBS cable. And no one complained, until I saw that and … well, he’s gone now. True thing… though there were probably other factors than this involved.

There are a small number of satellite/cable channels that occasionally try to pull one over on you by upscaling SD to HD in their broadcast, and usually screwing with the aspect ratio as well. So sometimes you’ll see that, but it would be restricted to a single channel at a time. This apparently lets them claim their channels are full time HD. Pretty common in the early days, pretty rare now.

-Dave

[Dave Haynie]

The FCC requires at least 1280×720 to be considered HD. But they only regulate ATSC broadcasts, not cable or satellite. They consider ATSC Digital TV, not HDTV; only 1280×720 and 1920×1080 are HD formats on ATSC… no others exist. The FCC had not put their stamp on any hard definition before the ATSC standard was finished… ATSC was there to define HDTV as well as DTV.

The Grand Alliance did a little backtracking.. before ATSC, which in turn pushed the formats for most of the HD stuff, Blu-ray, DVB-2, etc., it was generally considered HDTV if it was 1000 lines or more, but EDTV (enhanced definition) if it fell in the cracks between 480/576 lines and 1000. The CEA basically defined EDTV as anything from progressive NTSC (480p) up through sub-720p. But I don’t know of any FCC or other legal definition of that middle-ground, but the 720×480 allowed under ATSC would qualify.

Cable and Satellite companies, of course, have many more options for formats than those supported by ATSC. They might well be able to broadcast something that’s well into EDTV terratory.
-Dave

[Stephen Mann]

” Pretty common in the early days, pretty rare now.”

Not on Dish – almost everything on Dish is 720i.

Steve Mann
MannMade Digital Video
http://www.mmdv.com

[Dave Haynie]

I’ve been off Dish for a year (switched to DirecTV), but their quality actually went up a bit, HD-wize, once I was switched over to one of the new satellite slots (big dish that actually hits three orbital slots at the same time, same basic thing DirecTV does as well these days).

720i… no, I think that’s essentially impossible. Do you actually have transport stream captures that claim this? The problem is simple: the downrez gear everyone uses does its conversion on the TS stream, where it can lower bitrate and line resolution, but can’t do a proper frame conversion. So going from 1080i (which is practically all the material they receive from the providers, though sure, a few are based on 720p60, maybe still ESPN, not sure about ABC/Disney, and I think NatGeo) to 720i would completely botch the interlacing. While there are virtually no consumer televisions that can even display an interlaced signal anymore still for sale (progressive-only displays; they upconvert all interlaced), that would still be unacceptable. And 720i60 would be no savings over 720p30.

I know that DirecTV and Dish commonly downrez to 1440×1080. They consider that a freebie, because so much is shot at 1440×1080 anyway (DVC Pro, etc)… ABC was a big advocate for that, too, claiming that 1920×1080 was too artifacty for ATSC. Of course, ABC was also strongly lobbying for 720p in those days, pushed by their connection to ESPN.

Some channels get 1280×1080, and I know Comcast was caught on that, too, some years back. Not sure if they still do. FiOS doesn’t downrez… the have no need to… they essentially have 3x the bandwidth of any cable provider.

The other part of the equation is of course the bitrate… which is usually below 10Mb/s for either satellite provider. Still better than the 4-6Mb/s for 1080p from YouTube or the 3.6Mb/s “HD” from Netflix (though their more recent “SuperHD” is supposedly at up to 7Mb/s for 1080p24). Supposedly though, some Dish HD channels are as low as 5Mb/s… presumably at 1280x1080i60, or you’d certainly drown in artifacts. Given this is AVC encoding these days, you’d need 7-9Mb/s to match what you’re seeing in 1920x1080i60, OTA, MPEG-2… depending on how overloaded the local OTA channel is.

I’ve never heard of 720p60 stuff being downrezed, but of course they’re lowering the bitrate, and it wouldn’t be a hard trick to convert that to 720p30 in the inserter.

It’s also funny that satellite and cable companies are now advertising “premium” 1080p content. By which they mean 1080p24, which is of course a lower bandwidth signal than either 1080i60 or 720p60. I suppose the could improve the bitrate and maybe not downrez to 1440 in order to maybe deliver a better picture.

-Dave

[Angelo Mike]

So, if I get an HDTV, how do I get broadcasts to look good? TCM looks atrocious right now, whereas on my 50 pound Sony Trinitron it looks saturated and sharp by comparison.

[Scott Francis]

I use Dish, and it usually shows up (HD channels) as 1080i. I have some channels that have both SD and HD versions, with the HD versions you can “zoom” in and have the SD fill the entire screen. This of course adds noise and pixelation. If I leave it at “normal” SD channels are in the center and letter and pillarboxed depending on if it is 4:3 or 16:9. My HD channels look very good and sports especially.
On a sort of side note, my BR player REALLY up-rezes DVDs to a nice quality. I can tell, but was pleasantly surprised given how much it has to work with on a DVD.
When I shoot in HD (1080i or 1080p) I almost always deliver in DVD format. I see the material in HD and DVD on the same TV, and it looks pretty good off the DVD for the most part (thanks to the BR player). I obviously can tell a major difference from watching the HD files from my WD Live player (I watch final edits for plays and such before I convert to DVD).

But I digress, it is pretty amazing to see what hotels and such do with an SD signal. One also has to take into consideration that they don’t make CRT TV’s anymore, so a hotel and such upgrading may just be doing the TV’s and only had HD sets as an option..

Scott Francis
Mind’s Eye Audio/Video Productions

[Colin Morris]

I have found that a lot of hotel systems compress the signal to distribute it to as many rooms as possible. I regularly do rough cuts in hotel rooms and go HDMI from laptop to the TV. My footage usually looks way better than the hotel channels. The best HD I get is at home with an HD antenna.

Colin Mendez Morris
ArsMusica
http://www.arsmusica.ca