AV:Video Standards

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Broadcast Systems

Television started, if only for the lack of better technology, as a:

  • monochrome
  • live broadcast
  • "successor" of radio

These facts implied that not only a composite video signal had to be defined (in bandwidth, total and active lines, polarity) but also the matching audio signal (bandwidth, modulation) and also their carrier (channel bandwidth, frequency offset).

These are named by the CCIR with an uppercase letter, A through N. Most of these define variations on what is known today as standard definition (525/480 or 625/576 total/visible lines) but also include the historical British 410/377 and French 819/736 systems.

List on Wikipedia

Many TVs, especially those not intended for the North American and Japanese mass market, clearly specify which systems can be received over the air.


Eventually, by the time content started to become relatively less coupled to the medium of transmission, the world converged on the 525/480 @ 60 Hz and 625/576 @ 50 Hz video standards, which came to be named respectively EIA (RS-170) and CCIR after the main promoting groups.

Note that, while an EIA signal can correctly be called NTSC (as the standard was indeed linked to the NTSC association), it is incorrect to use the term "PAL" for 50 Hz video in general.

Color Encodings

Later, backwards compatible methods for adding a color signal to composite video were added, of which 3 were ultimately accepted: PAL, SECAM, and NTSC.

The full name of a combination is composed of the color standard followed by the system (which also specified the color carrier frequency, typically 3.58 or 4.43 MHz): PAL-G, NTSC-M, etc.

They are most commonly coupled to a CCIR signal and 4.43 subcarrier for the former two and EIA/3.58 for NTSC, but this is not always the case, with the main exception (PAL-M) being used in Brazil. Other blends exist outside of broadcast standards such as NTSC 4.43 and PAL60.

In fact, the timings of EIA's standard were slightly modified so that the colorburst could be defined as a multiple of the deflection timings, resulting in a new vertical frequency of 59.94 Hz.