Tuesday 24 December 2013

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NTSC and PAL video standards

NTSC and PAL video broadcasting standards

There are currently two types of analog format used to broadcast video signals throughout the world. Certain parts of world use NTSC, which stands for National Television System Committee, while other parts of the world use PAL, which is short for Phase Alternating Line. There are several important differences between PAL and NTSC signals which are good to know about since they affect how certain technologies (such as DVDs) work in different countries. This Bamboo AV Advice article will help you to understand the differences between NTSC and PAL video standards, and will give you a good overview of what will happen to television systems and broadcasting standards in the future. NTSC will be the first video standard examined, followed by PAL.

NTSC format

NTSC stands for National Television System Committee, and is the analog format used by the majority of television American broadcasters. NTSC was developed in 1940 to establish a common broadcasting standard following the popularity of television and the introduction of analog television signals. NTSC images conform to a standard of an interlaced image made up of 525 horizontal lines with a refresh rate of 30 frames per second. Any standard definition picture with a maximum horizontal resolution of 720 lines and a 480 vertical resolution limit with a frame rate of 30 frames per second can be defined as NTSC and will play on a device designed for NTSC television. Numerous amounts of consumer video products, such as DVDs have been tailored to work to this standard and thus output in a resolution of 720 x 480. If a DVD uses an unsupported digital standard, many manufacturers of DVD players have implemented the ability to convert the signal to analogue and “squeeze” the image frame to fit the video.
Countries using NTSC
NTSC signals are used predominately in the Western hemisphere. The territories and some of the more notable countries that use NTSC broadcasts are listed below.
North America
Canada
Mexico
United States
Central America and the Caribbean
Costa Rica
Cuba
Guatemala
Honduras
Nicaragua
Panama
South America
Bolivia
Columbia
Peru
Asia
Burma
Japan*
Philippines
South Korea
*Japan uses a variant known as NTSC-J that has a slightly lower level of darkness.

PAL format

PAL, which stands for Phase Alternating Line, is the video standard used primarily in Europe and Africa for displaying television, DVD, and VHS pictures. The system was primarily introduced because of the inability of the 50 Hz power grids in European countries to accept the existing 60 Hz NTSC standard, and because of the colour shift that can occur during poor transmission weather. As a result, in 1963 Walter Bruch of Germany unveiled a television standard with a frequency of 50 Hz and a better quality picture than NTSC.
The PAL format outputs interlaced images at a resolution of 720 x 576 (86 more vertical lines than NTSC) with a refresh rate of 25 frames per second (5 less than NTSC). This means that while PAL broadcasts have a superior picture quality, NTSC images appear smoother, especially during high motion footage such as action films or sports.
Countries using PAL
PAL signals are most common in Europe and Africa. The territories and some of the more notable countries that use PAL broadcasts are listed below.
Africa
Nigeria
Ghana
Cameroon
South Africa
Asia
China
India
Philippines
Vietnam
Europe
Czech Republic
Denmark
Ireland
Italy
Poland
Portugal
Romania
Spain
Ukraine
United  Kingdom
South America
Argentina
Brazil
Paraguay
Uruguay
Oceania
Australia
New Zealand
A map showing the parts of the world that broadcast in PAL and NTSC
The image above shows a world map of the distribution of PAL and NTSC video standards usage.
The future of NTSC and PAL
In the last few years the penetration of High Definition televisions into homes has been consistently on the rise. As a result there has been an increased amount of demand for digital signals that can contain 5.1 audio and High Definition broadcasts. Both NTSC and PAL are analog formats, which means that they have a limited bandwidth incapable of broadcasting Dolby Digital sound or High Definition images. In the near future there will be little need for these analog signals.
Numerous countries around the world have set mandates to phase out and stop any further analog broadcasts and replace them with digital high definition broadcasts. For America, on February 8th 2006 George W. Bush signed the “Digital Television Transition and Public Safety Act of 2005” into law. This set February 17th 2009 as the date when all NTSC transmissions will be turned off permanently. NTSC broadcasts will be replaced with ATSC (which stands for Advanced Television Systems Committee), a standard that will broadcast digital High Definition images.
In Europe there are already countries that have fully converted to digital signals. The countries currently using the new digital format DVB – T (Digital Video Broadcasting – Terrestrial) are listed below:
Andorra
Finland
Luxembourg
Netherlands
Sweden
Switzerland
The remainder of the European countries have all set deadlines similar to those of the United States for when PAL broadcasts will be permanently stopped.

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