Talk:NTSC

History: CBS system

How come the early CBS system had 24 effective frames/sec but 144 fields/sec? Did it split each frame into 144 / 24 = 6 fields? That's the logical explanation to me, but the way it's written now, it seems a bit obscure and confusing, so the section would probably benefit from adding that fact if it's true. --79.193.57.210 (talk) 21:00, 8 June 2010 (UTC)\

It's true that the CBS analog system (briefly the law of the land--FCC) used 6 fields per frame. Ohgddfp (talk) 16:09, 6 January 2024 (UTC)

How about compare CBS with French television channels. Compare NBC with England television channels. Compare ABC and FOX with German television channels. Are the frozen pictures look any opposite? --DuskRider 08:33, 5 December 2012 (UTC)

Upcoming Fix - Discretization

About "This process of discretization necessarily degrades the picture information somewhat, though with small enough pixels the effect may be imperceptible.": Where is the source? We need to find a reliable source for this. Otherwise, I will delete the above quote from the article. Or, ....... not. So here's my argument. From sources on this subject over the years, I've found that discretization is a lossless process, meaning that, unlike that for many other kinds of operations where mathematically, there exists a minimum degree of degradation, discretization has no such minimum degree of degradation. In other words, with discretization, as with many other kinds of signal processing, there is no mathematical limitation as to how small the degradation can be.

So in NTSC, degradation caused by discretization can be minimized to any desired degree through hardware improvements. But that can be said about almost all operations. So why single out discretization? This is not an NTSC problem in reality. It gives weight to something that, due to hardware imperfections, is no worse than just about any other signal processing operation. Giving such weight to something without a good source to back it up only confuses the reader. Since this is actually in the realm of mathematics, I am waiting for a mathematical proof from a reliable source, that discretization "necessarily degrades the picture information somewhat". Since this is a mathematical issue, the source must be compatible with mainstream science. - A source, anyone? Ohgddfp (talk) 02:06, 13 December 2013 (UTC)

The section on colour encoding needs to be looked at by someone who really knows this subject well. The lower half of this section has some pretty specious explanations about scanning rates, dot patterns and sound IF frequencies. For starters I don't think these topics should be in the article at all. How is Mr Average supposed to understand any of this Gobbledygook? Spyglasses 10:31, 1 February 2014 (UTC) — Preceding unsigned comment added by Spyglasses (talk • contribs) ---

From Nyquist–Shannon_sampling_theorem if you sample a band-limited signal with a sample rate greater than twice the bandwidth, no information is lost. Video sources are normally band limited, so this should not be a problem. Actually Nyquist sampling requires that the signal be available over an infinite time span, but it is plenty close enough for usual video and audio sources. The loss comes later, when MPEG compression is done to the sampled signal. In signal processing, there is also quantization, relating to the finite number of values at each sample point. With uniform sample spacing, this results in quantization noise with amplitude about half the quantization step. Quantization noise is fundamental in any digital system, but can usually be made low enough, compared with other noise sources, such as thermal noise. Gah4 (talk) 16:59, 12 May 2017 (UTC)

Yes, digitization always causes quantization noise, which indeed is a degradation of the picture information. Hopefully such degradation banding is not usually noticable. Now discretization, required by digital systems, also occurs in some analog systems where the signal is sampled, but not digitized. This is sampled analog. There are some video tape time-base correctors (used for color under VCRs inside cable TV studios--I myself used them--that are this kind of sampled analog, using analog memory cells in a fire bucket delay arrangment. So sampled (discretization) analog degrades only by hardware imprefections, as any operation in analog is degraded by hardware inperfection. Analog disretization has no inherent picture information degradation at all. Ohgddfp (talk) 16:39, 6 January 2024 (UTC)

Uhh... what?

Quote:

"

This standard is slowly being replaced by HDTV.

"

HDTV (high-definition television) is not a "standard", it is an ambiguous comparitive term describing the resolution of nearly any video mode. NTSC is not being "replaced by HDTV", it is being replaced by newer video systems that support high-definition modes. Once upon a time, 405-line television System A was once considered "high definition" compared to the previous 30-line Baird system, as the later 625-line system was to A.

NTSC definition of the acronym

I've seen NTSC as an acronym for "National Television System Committee", but somewhere I read it was National Television Standards Committee. Is it possible that the latter was also used, or that it became one or the other over time? Misty MH (talk) 08:14, 5 January 2017 (UTC)

The NTSC called themselves the "National Television System Committee". It was never officially changed to anything else. See their 1953 publication: "Petition of National Television System Committee for Adoption of Transmission Standards for Color Television". This can be found in Google Books. Ohgddfp (talk) 16:50, 6 January 2024 (UTC)

change to past tense?

NTSC is obsolete. I’m contemplating changing the front end of the article from present tense to past tense. Comments? Cpoynton (talk) 17:12, 22 August 2024 (UTC)

Obsolete doesn't necessarily mean past tense. You might consider MOS:TENSE. Past events are past tense. The NTSC system was formerly used for broadcasting in the US. But the standard itself, written on paper, still exists. And many devices still output a signal satisfying NTSC. (DVD players and DTV converter boxes, for two.) I suspect that the important events are already past tense, but you can check for that. Gah4 (talk) 18:16, 22 August 2024 (UTC)

OK, in the case of is the first, I prefer present tense, but others disagree. (Once first, always first.) As noted, the term NTSC is still used for DVDs designed for NTSC countries, especially with 60Hz or 56.94Hz displays. So the term itself isn't obsolete. Gah4 (talk) 18:21, 22 August 2024 (UTC)