Television System Video Standards
Broadcast television systems are encoding or formatting standards for over the air television. Television stations broadcast in one of these standards, the standard being used depends on the region.
NTSC
VIDEO STANDARD: NTSC is the analog standard television system in the United States and North America.
The National Television System Committee (NTSC) was formed in 1940 and devised a television standard in 1941 for black and white televisions for improved interoperability among television manufacturer products.
NTSC uses 525-Line / 60 field 480i standard definition (SD) resolution. The NTSC resolution on the vertical axis is lower than the European standards, 525 lines against 625.
NTSC altogether uses 525 scan lines, thereof approx. 485 are visible. The refresh rate is 29.97 Hz or 29.97 fps respectively. This corresponds to 59.94 Hz (interlaced - half-images) or 59.94 fields/s (59.94?) respectively which can be derived from the NTSC 2:3-Pulldown based on 23.976 fps of NTSC films. The digital standard resolution is 720x480 pixel for DVDs.
PAL
VIDEO STANDARD: PAL is the analog standard television system in Europe.
Phase Alternating Line (PAL) is a color encoding system for analogue television used in broadcast television systems in most countries broadcasting at 625-line / 50 field (25 frame) 576i standard definition (SD) resolution. PAL is designed with a frame rate of 25 to make it compatible with the 50Hz electrical systems of Europe. PAL and NTSC are not compatible.
PAL altogether uses 625 scan lines, thereof approx. 575 are visible. The refresh rate is 25 Hz or 25 fps respectively. This corresponds to 50 Hz (interlaced) or 50 fields/s respectively. The digital standard resolution is 720x576 pixel for DVDs. Related to NTSC, PAL has a shorter run time because of the higher amount of "fps" - PAL movies are (normally) not cut, but they are "faster" (PAL Speedup). When film is covered for transmission over PAL, the simple conversion results in a playback flaw known as PAL Speedup.
SECAM
VIDEO STANDARD: SECAM is the video standard first used in France.
Sequential Color with Memory (SECAM) is similar to PAL. The French developed SECAM and it later became adopted by former French and Belgian colonies, Greece, and the Soviet Union.
ATSC
VIDEO STANDARD: ATSC is the current digital television standard which is designed to replace NTSC in the United States for over the air transmission. ATSC provides for high definition including the 16:9 wide screen format up to 1920x1080 pixels as well as high definition sound using the Dolby surround sound Digital AC-3 format.
The Advanced Television Systems Committee (ATSC) sets standards for digital television transmission over terrestrial, cable, and satellite networks. ATSC replaced much of the analog NTSC television system in the United States on June 12, 2009, and on August 31, 2011 in Canada. The ATSC system supports both forms of scanning (progressive or interlaced.)
QAM
VIDEO STANDARD: Auadrature Amplitude Modulation (QAM) is used by Cable TV providers. QAM television tuners allows for the reception of unencrypted digital signals from a cable provider.
Related
- Cinema Aspect Ratios.
- Film, PAL, and NTSC Compared
- Subscription Free Digital Video Recorder
- Television System Video Standards
