Talk:576i

As I understand it, 576i and 576p were not included in the original ATSC specifications. Obviously if North American broadcasters included 576 formats it would allow them to carry PAL and SECAM programming at its native resolution instead of up or downconverting, but I don't know whether that is or ever will be the case. Lee M 02:50, 2 Feb 2005 (UTC) (copied from Talk:576p - see that page for further discussion)

== This entry should be deleted.

576i/p relates only to PAL/SECAM/DVB and has nothing to do with ATSC. 576i/p can have an aspect ratio of either 4:3 or 16:9. See Digital Broadcasting Australia or Digital Video Broadcasting for more information/proof. This item should not be deleted.

Spelling

WP:ENGVAR says we should "consistently use the same conventions of spelling and grammar" and, "If an article has evolved using predominantly one variety, the whole article should conform to that variety" and, "An article on a topic that has strong ties to a particular English-speaking nation uses the appropriate variety of English for that nation." So I've tried to ensure that the spelling is the same as introduced in the first revision I could find that expressed a preference [1] ... richi (talk) 22:32, 19 January 2008 (UTC)

Pixels

"The 576 identifies a vertical resolution of 576 lines (usually with a horizontal resolution of 720 or 704 pixels)" - Where is 720 and 704 pixels used for width? I've only seen 702 used. Davhorn (talk) 18:36, 24 February 2008 (UTC)

• D1 is 720. The highest resolution SD channels broadcast over the various DVB networks are 720. There are various lower resolution formats, but 702 doesn't make sense because it's not a multiple of eight ... richi (talk) 14:45, 25 February 2008 (UTC)

Well, both DVDs and D1 follow the CCIR 601 raster format which does define the horizontal resolution as 720 pixels. BUT it also defines that the time it takes to draw such a line should be 53.333µs. PAL uses 52µs and NTSC uses about 52.666µs, meaning that not all 720 pixels can be used. With PAL DVDs for example, only the middle 702 pixels are used (9 pixels on each side should be black if it follows the standard) and I guess for NTSC it would be somewhere between 710 and 711 pixels (forgot about that one in my original post). So saying the width is then 720 pixels is a bit misleading... Davhorn (talk) 22:44, 25 February 2008 (UTC)

Increasingly, that's a big "if", but in terms of what is actually broadcast or stored on the disc, the MPEG2 TS stream contains up to 720 pixels across—I'm also aware of 544, 528, 480, and 352 being used. 720, 704, and 544 are in common use on DVB-T here in the UK, for example -- see [2]. See also Overscan#Important_esoteric_values ... richi (talk) 00:01, 26 February 2008 (UTC)

288i?

Is there a source for As some people prefer to identify an interlaced resolution by its number of field lines (rather than the number of frame lines), the format is also sometimes called 288i? I've never heard of this, and couldn't easily find any references to 288i anywhere. It seems like following the standard, 288i would mean two fields of 144 lines each - which may well have its application. Anyone object if I delete the sentence? Blackworm (talk) 05:20, 25 March 2008 (UTC)

History and Origins

The article should have more about the history of the 625 line (576i) system. its development and early use etc ? 213.40.227.50 (talk) 20:40, 6 February 2009 (UTC)

Agreed Ive heard the Germans, Russians and even Americans (postwar occupation troops in Germany) credited with the development of the 625 line system and various dates (1941-48) bandied about. Does anyone know more about who/when/how/why "625" was developed ? 92.4.236.87 (talk) 19:12, 8 April 2013 (UTC)

Why it was developed is easy. Because of primitive electronics at the time, systems had to be based on simple division ratios. 625 is 5x5x5x5, an easy number to generate, as was the field blanking of 25 (5x5) lines.Wmck (talk) 18:50, 28 December 2014 (UTC)

according to this [3] article the 625 line analogue television system was devised in 1946 by two German engineers, Moller and Urtel In Geneva a Mr W. Gerber proposed this as an European system the USSR came up independently with a very similar system. 90.202.231.149 (talk) 21:15, 28 November 2015 (UTC)

Further discussions on the origin of the "625 line" system here [4] Not all implementations used 576 active horizontal lines. System I originally used 582. 2A00:23C7:70C:EF00:89AB:53F7:8297:ADC (talk) 18:35, 29 June 2021 (UTC)

576i speed-up

Has anyone considered that telerecordings of programmes made on 25 fps systems will actually suffer slowdown if telecined at 24 fps? This was certainly true of the 1953 Coronation footage when screened on US and Canadian TV, and may still apply to a handful of films such as The Best of Benny Hill which contain 25 fps footage originally shot on videotape.

A criticism of that section in the article: Your player may be able to play a 23.976fps DVD or BluRay, but what good does it do if you don't have a natively progressive display? Thus, what most standalone DVD and BluRay players do with such a disk is either speed them up or apply an NTSC pulldown on-the-fly, in order for the footage to be displayable on NTSC, ATSC, and PAL displays. Native-progressive players are expensive and can only be used in conjunction with native-progressive displays. --87.151.27.43 (talk) 19:27, 27 August 2012 (UTC)

Horizontal resolution

Could someone add the horizontal resolution to the article? Thanks. ➧datumizer  ☎  19:18, 24 June 2020 (UTC)

Confusion with analog 625 lines

The article is about the digital resolution 576i but it talked about the analog 625 lines systems... Therefore I removed all that, and limited analog talk to the Operation topic, where it makes historical sense. Elsewhere, we always talk about digital applications (DVB, DVD, etc...) I hope it's clearer now. 4throck (talk) 00:46, 30 December 2021 (UTC)