Talk:Standard-definition television
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[edit] SDTV article
You DO have an article called "Standard-definition television." I have been reading
it! Maybe, your <HEAD> is not coded exactly right, or maybe there is a glitch in the Search-engine, or something,
but, you DO have an article of that title. It is located [according to my browser's address slot] at
http://en.wikipedia.org/wiki/Standard-definition_television
Here's the erroneous text that appears at top of
this page I am typing into, which page is addressed at
http://en.wikipedia.org/w/index.php?title=Talk:Standard-definition_television&action=edit
Editing Talk:Standard-definition television
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We don't have an article called "Standard-definition television"
- Search Wikipedia for Standard-definition television - it might be called something else.
Have fun. This is a great service, wikipedia. Best wishes. I'm not logged in - you may acknowledge to me at basketx7@7aol.com. (Remove spam-fighting 7s first.) —The preceding unsigned comment was added by 63.210.89.130 (talk • contribs) 17:49, May 28, 2006 (UTC)
[edit] Copyright Violation?
Looks like vast swaths of this article are taken from this page here. If one of the authors wants to stand up for this work, now is your chance to do so. If you wrote it originally for this article and the site in question has lifted that. If, however, you lifted the text from that page and put it here, please just remove it and say so... and please don't do it in the future ;) I'll revisit this in a week or so to look for development. As an aside, as I look at this article, I can't help but wonder if we would be better served just redirecting Standard-definition television to 480i instead. --Reverend Loki 22:45, 27 March 2007 (UTC)
- Even if the author of the original content submitted this to Wikipedia, it's still not of a suitable standard for an encylopedia. The original article contains many glaring inaccuracies, biased and unsubstantiated assertations and some complete gibberish. Here are some gems:
- "SDTV is a digital format that provides a high quality picture, very similar to that of digital versatile disk."
- "The quality of these new digital transmissions will become the standard for the future of broadcasting."
- "In order to fully experience SDTV or HDTV, you will need to buy a new television set."
- "SDTV will give a greater range of choice in the type of viewing material you will be able to access. Children's programs, documentaries, films, and public affairs -- the choice will be far greater than before."
- "These [high definition] television sets were very expensive, much like when the first compact disc players appeared."
- I vote this article be removed forthwith. M0thr4 12:06, 29 March 2007 (UTC)
- Yeah, I agree that the quality of the content of the article is pretty low. However, I wasn't about to start trying to fix an article that may be about to be deleted anyways. I suspect I will be soon deleting vast swaths of this one and suggesting a merge with 480i. --Reverend Loki 16:57, 29 March 2007 (UTC)
[edit] Incorrect Pixel Aspect Ratios
The pixel aspect ratios (PARs) listed for NTSC 720/480 and PAL 720/576 (8/9, 16/15 and their anamorphic counterparts, 64/45, 32/27) are incorrect.
They were all derrived from the assumption that the active display area, i.e. one of perfect aspect ratio 4/3 (16/9) is the entire 720*480 and 720*576 display, which is wrong. The actual active display area is
710.85 * 486 for NTSC 702 * 576 for PAL
or, taken approximately
704 * 480 for NTSC 704 * 576 for PAL
Therefore, the PAR of NTSC 720/480 is the same as of NTSC 704/480, i.e. 10/11 standardly and 40/33 anamorphically. Similarly the PAR of PAL 720/576 is the same as of PAL 704/576, i.e. 12/11 standardly and 40/33 anamorphically.
Unlike the 704-vertical-line (NTSC and PAL) display, for 720-vertical-line one the display aspect ratio (DAR) is no longer 4/3 (or 16/9). Indeed, it is
720/480 * 10/11 = 15/11 for standard "4/3" NTSC display 720/576 * 12/11 = 15/11 for standard "4/3" PAL display 720/480 * 40/33 = 20/11 for anamorphic "16/9" NTSC display 720/576 * 16/11 = 20/11 for anamorphic "16/9" PAL display
If we (very roughly) consider the standard display pixel as a E*E square, then the above approximated PAR still have an error of ~2*E on standard display and ~3*E on anamorphic display. There are better approximations which give error much less than 0.5*E, for example [1]:
PAR = 128/117 for PAL 720/576 and PAL 704/576
PAR = 72/79 or (even better) PAR = 4320/4739 for NTSC 720/480 and NTSC 704/480.
[1] Jukka Aho: A Quick Guide to Digital Video Resolution and Aspect Ratio Conversions. http://www.iki.fi/znark/video/conversion/ —Preceding unsigned comment added by 118.68.183.131 (talk) 15:44, 17 February 2008 (UTC)
[edit] Definition of SDTV
In USA, SDTV refers to digital television broadcast in 4:3 aspect ratio, the same aspect ratio as NTSC signals. It has to do with the resolution, not the aspect ratio. The reference provided also does not support the claim - it doesn't define SDTV. SDTV is 480i, EDTV is 480p, and HDTV is 720p, 1080i or 1080p.--RLent (talk) 16:40, 30 April 2008 (UTC)
[edit] Standard Definition / High Definition
To my memory, when the BBC launched 625-line television, it was described as High Definition Television, it seems a little odd that this terminology can now be applied to the present as the old HDTV becomes SDTV and a new HDTV takes over - is there really any such thing as Standard or High Definition Television? The terminology is not used in other mediums - photographs/resolutions are mega/pixels. It is like saying the temperature is hot at 25c and the next day saying 26c is hot. I know there are the 1080 and 720 formats but why wasn't megapixels good enough for this? And I notice there is Extended Definition and Enhanced Definition available also. Seems anything to confuse the common folk is good for the industry. pebbens (talk) 01:29, 9 March 2008 (UTC)
- Even the original British 405 line system was called "high definition" when it was first transmitted in the 1930's. Early experimental TV systems had as few as 12 lines. For decades the term fell into disuse because all TV was in the same ballpark, so it was revived to describe the new 1000+ line systems. Algr (talk) 05:45, 22 May 2008 (UTC)
