Talk:Enhanced-definition television

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[edit] Rewrote the article

Now I need someone to check grammar and spelling. DCEvoCE (talk) 00:02, 22 March 2008 (UTC)


[edit] Is 480p24 or 480p30 considered EDTV?

"EDTV signals are often broadcast in a 16:9 aspect ratio, and are generally considered equivalent in picture quality to the DVD format."

O rly? A motion picture or filmed television series consists of 24 or 25 frames per second. DVD of a motion picture or a filmed television series is in effect 720x480p24 (NTSC or PAL-M at 2:3 cadence), 720x480p25 (NTSC or PAL-M at 2:2:3:2:3 cadence used in NTSC releases of some European films and in some TV airings of North American films that are compressed to allow for more advertisements), or 720x576p25 (PAL). The 480p article and the {{TV resolution}} template seem to imply that a 480p signal has to have 60 distinct frames per second to be considered EDTV, meaning that a motion picture in EDTV must be at least 720p. --Damian Yerrick (☎) 19:30, 24 March 2006 (UTC)

Frame rate is irrelevant to whether or not something is EDTV. "Definition" refers to sharpness, not smoothness of motion. Only pixel count, compression, and the presence or absence of interlace come into account. It's debatable whether or not a signal from a DVD could be considered EDTV. IMHO: If it it pure progressive 24p, perhaps, but not if it has been de-interlaced. Algr 15:46, 27 April 2006 (UTC)
What is the practical difference between a pure progressive signal and a properly deinterlaced signal? --Damian Yerrick (☎) 23:51, 1 May 2006 (UTC)
1) If you are viewing an interlaced signal from a DVD, the best connectors you could be using is analog component. That signal would then have to be re-digitized before it could be de-interlaced. This processing would cause signal loss compared to routing a progressive signal directly to a CRT. (This might not effect non-CRT displays, which have to digitize any analog signal no matter what.)
2) I'd question if a de-interlacer could ever be perfect, given the realities of DVD mastering. Often content that you'd think ought to be progressive, such as movies, end up being encoded in interlaced form for obscure production reasons. For example, in the DVD of the movie "Adaptation", the movie is progressive, but the bonus clips of ads for the movie are interlaced. I've no idea why. The ads look much worse then the movie on my computer's LCD screen, but on a regular TV, there is no difference since it is all interlaced.
3) When video is viewed on interlaced screens, the image must be blurred slightly (anti-aliasing) to prevent fine details from making one field brighter then the other and thus causing flicker. When you put the fields back together, you can't get that detail back. Anti-aliasing on DVDs happens during the mastering phase - players expect this to already be done. So even progressive DVDs aren't as sharp as a theoretical 480p DTV broadcast could be. Algr 05:18, 2 May 2006 (UTC)
1) I was referring to the fact that DVD signals are stored interlaced on the disc, even if they are deinterlaced to 480p24 inside the player.
2) Yes, a perfect deinterlacer is possible as long as it can detect the cadence (using field differencing) and field dominance. If your DVD player has a poor deinterlacer, it's your DVD player's fault.
3) My Apex AD-1200 has picture modes HI-RES and NONFLICK. This "NONFLICK" mode must be there to compensate for DVDs that are not blurred in mastering. --Damian Yerrick (☎) 16:29, 2 May 2006 (UTC)
1) Films on DVD are supposed to be stored in 24p. (Any player can convert it to 60i for output.) However often the encoding is not done that way, for example if they start with a videotape transfer intended for laserdisc, or if a promo was edited on video gear that doesn't support 24p. Only then would the de-interlacer in your progressive scan player have to start guessing what field goes where.
2) This is circular reasoning. A perfect airplane is possible as long as it doesn't crash. There are also very difficult situations like a program shot on PAL and mixing film and video footage together, then converted to NTSC.
3) I've only seen one DVD that I suspected was not blurred for interlace - It was an anime, and looked rather harsh on my TV. The nonflick mode you describe would probably have helped, but next to no one is going to understand what that means and when to turn it on. Algr 17:03, 2 May 2006 (UTC)
I need to edit that "Television resolution" chart, because it is wrong to include 720p in EDTV, and there is no such thing as 720i. But I can't figure out how to access it. What am I missing here? Algr 15:46, 27 April 2006 (UTC)
To edit any (unprotected) template used in any page: Go to the article, click "edit this page", scroll down to "Templates used on this page", click one, and click "edit this page" again. --Damian Yerrick (☎) 23:51, 1 May 2006 (UTC)

[edit] Is there a SMTPE or ITU standard for 480p television?

It would be helpful if these pages told the names of the standards.

-- user:GregGarner

I don't think they have names other then 480p, 576i ect. Unless you mean this: ATSC

[edit] EDTV TV Channels

Anyone have a list of channels that broadcast in EDTV? —The preceding unsigned comment was added by 84.255.168.44 (talk) 06:30, 10 January 2007 (UTC).

[edit] ED Question

There is one question that this page doesn't seem to answer. Can the normal crts, the ones that millions of people have owned for the past 15 years, display ED? Or is it only possible on the newer HD sets? JayKeaton 10:25, 6 April 2007 (UTC)

The biggest requirement is the ability to scan at 31.5 kHz. Any "computer" CRT dating back to VGA (1987) can do this. (You may need an adapter to convert YPP components to RGB+sync components.) But "standard resolution" CRTs such as those used in SDTV sets and JAMMA arcade monitors can display only SDTV. --Damian Yerrick (talk | stalk) 11:34, 6 April 2007 (UTC)

I m french so excuse me if my english is far from perfect. I thought till today that only newer sets could display ED. Thought it seems to be wrong. The Sega Saturn (1994) was able to output ED via a special video cable (currently a scart cable) on japaneese TV. I know some old TV also capable of ED via RGB Scart (Sony KVS2911B).It may be the case for every high cost TV system of that period.

[edit] HDTV or not?

"EDTV generally refers to video with picture quality beyond what is broadcastable in NTSC or PAL, but not sharp enough to be considered High-definition television (HDTV)."

However, near the end of the article, there's also this:

"In the United States, the ATSC official DTV formats include SDTV, and HDTV. EDTV is considered part of the HDTV standard."

To my understanding, a 480 (or 576) line resolution is not "High-definition" by any widespread standard, that term only being used to denote the 720p and higher resolutions. Unless I missed something here. At any rate, this contradiction should be noted. RyokoYaksa 23:53, 12 July 2007 (UTC)

[edit] 50% more perceived vertical resolution than interlaced

The statement "50% more perceived vertical resolution than interlaced" is only true in the context of a moving subject, but its entirely false in the case of a stationary subject. Anyone want to come up with a better wording? --Ray andrew 17:48, 24 September 2007 (UTC)

  • Even a stationary subject needs to be filtered vertically to some extent so that fine horizontal lines on the subject do not appear to flicker. --Damian Yerrick (talk | stalk) 21:01, 25 September 2007 (UTC)

[edit] Merge from Extended-definition television

Support - I support merging Extended-definition television into Enhanced-definition television. A simple move of content from Extended-definition television, while keeping non-duplicate data would be fine. — IncidentFlux [ TalkBack | Contributions ] 10:36, 12 March 2008 (UTC)

Weak Support - since both articles are rather short. They do seem to discuss different things, however. Enhanced is basically about the current DTV standards in 480p mode, while Extended is about what we DIDN'T do with NTSC to improve it's quality. If we get a good deal of info about rejected attempts to improve NTSC in the '90s, then it might be worth it to have separate articles Algr (talk) 16:39, 12 March 2008 (UTC)

[edit] Mention of the 854*480

I don't know much about the resolution standards, but the graph in the article clearly seems to state that 854*480 is what EDTV is. Yet this format isn't mentioned even once in the article. Shouldn't it be? (It's in the green part here:)

EDTV Resolutions.png

--LeGUIGUI (talk) 15:45, 18 April 2008 (UTC)

That resolution has been a long standing headache for the article. Some plasma displays used to be made at 854 x 480 pixels, but nothing was ever natively shot or broadcast at that pixel count. Actual broadcasts use 704 or 720 pixels horizontal. But this uses non-square pixels, so if you draw a rectangle with 720x480 pixels, it comes out with a non-standard 2:3 aspect ratio. Since people drawing the chart need 854 pixels to make the shape of the screen 16:9, that is what we keep seeing. Algr (talk) 21:29, 18 April 2008 (UTC)
So basicaly, EDTV have a 720*480 resolution, but the use use of non-square pixel give it the size of a square pixel screen of 854*480, right? And if an ED video (720*480) is diplayed by an HDTV with square pixel and 16/9 ratio (for example, 1280*720) it will be interpreted as a 854*480 video and then upsacaled to the size of the screen. Did I get it right?--LeGUIGUI (talk) 00:47, 19 April 2008 (UTC)
Close. An HD set would resample the 720 horizontal pixels directly into whatever it's native horizontal resolution was. (1280 in your example) There would be no need to turn 720 into 854 first. Another example of non-square pixels is the anamorphic lenses that can be placed on any camera (film or video) to change it's aspect ratio. It doesn't change the number of pixels or film grains you have, it just changes there shape, and thus the shape of the screen. Algr (talk) 18:58, 20 April 2008 (UTC)