TV Systems

TV Systems

Analog television encoding systems by nation; NTSC (green), SECAM (orange), and PAL (blue)

The Concept

A TV System is two things:

1. Line system TVL (televison lines) that raster luminosity, of course black and white TV systems are just a line system.
2. Colour encoding system that decides how the color is added to the luma picture.

The 3 Global SD Signal Standards (Camera to Device Output/Input)

Common Name	Line System	Standard Name	Full-Frame 4fsc	Active Area Resolution	IMX Resolution	Frame Rate	Field Rate
NTSC	525-line	525i29.97	910x525	720x480 & 720x488	720x512	29.97fps	59.94i
PAL	625-line	625i25	1135x625	720x576	720x608	25fps	50i
SECAM	625-line	625i25	1135x625	720x576	720x608	25fps	50i

• IMX full-height sampling preserves the top VBI area.

• There is also 405-line, 655-line & 819-line systems but these are rare to be encountered by most readers today, and should be preserved with RF capture or RAW CVBS capture as standard existing baseband capture methods always converts the signal or won't even support decoding of it at all.

• The base frame/field rates were based around the power grids japan being the odd case of having both 50Hz & 60Hz grids.

Formats and there outputs you will find on Tape VCRs

Common Name	Line System	Colour System	Sub-Carrier	Notes
NTSC	525-line	NTSC	3.58 MHz	Native NTSC
PAL	625-line	PAL	4.43 MHz	Native PAL
NTSC 4.43	525-line	NTSC	4.43 MHz	Up-converted colour carrier
PAL60	525-line	PAL	4.43 MHz	NTSC converted to PAL
PAL-N	625-line	PAL	3.582056 MHz	PAL with NTSC carrier rate
PAL-M	525-line	NTSC	3.575611 MHz	Near NTSC colour carrier
SECAM	625-line	SECAM	4.25 and 4.41MHz	Bloody French just had to...
MESECAM	625-line	Modified SECAM	?	Consumer recorded SECAM

Things of Note

PAL - B,D,G,H,I broadcast transmission types are FM Modulated for broadcast per region.

A key thing in baseband and recorded format world is that source feeds and production footage is virtually only from NTSC/PAL native camara sources and there is some SECAM but that was virtually all converted to PAL or supported by PAL conversion by the time of digital era production.

Notably these regional differences in broadcasting can have there own quality factors.

Some NTSC 3.58 / PAL 4.43 only equipment won't support decoding of NTSC 4.43 colour such as Skynet TBC units, but devices like a native PAL DMR-ES10 will convert the signal to a 25i frame shifted PAL colour image for example.

PAL-M Brazil 1972-2000 intordeuced the PAL60 with a 525-line system but PAL colour.

PAL-N Argentina, Paraguay & Uruguay, 625-line but with NTSC colour.

NTSC-J NTSC but with a 0 IRE black level adopted in Japan. (Standard NTSC encoding otherwise) (Note: they have a 50hz & 60Hz power grid but adopted NTSC/29.97i)

SECAM The French's standard for colour encoding before virtually all regions switched to PAL, found in France, USSR, French Collonised regions and parts of the Middle East, in the digital era, most PAL equipment in the later 90s and 2000s supported playback and or conversion of SECAM.

NTSC Tape Playback on PAL Systems

NTSC 4.43 uses NTSC at 4.43MHz

PAL60 uses PAL at 4.43MHz (called Playback on PAL TV on most devices).

Both with 29.97i (59.97i) frame and 525 line rates

PAL has 4.43Mhz colour sub-carrier native.

NTSC has 3.58Mhz colour sub-carrier is native.

PAL equipment with duel support will output one or two flavors of NTSC (with multi system decks supporting 3 if you include native NTSC) for example Digital8/Hi8 PAL units for example have both NTSC 4.43 & PAL60 options so do some duel system DVD recorders.

Thanks to Stephen Neal for breaking this down:

NTSC and PAL are two different chroma encoding systems, now PAL is based on NTSC - but improves on it by flipping the phase of one of the components on alternate lines (hence the name Phase Alternate Lines)

That means if you use a delay line PAL decoder, the phase errors in pairs of line cancel each other out, and become saturation errors (which are far less noticeable than hue errors), if you don't use a delay line and instead use Simple PAL decoding then you get inverted phase errors on alternate lines which your eye/brain is supposed to average at distance (so-called Hanover Bars).

PAL60 basically converts the NTSC 627kHz colour-under signal to PAL 4.43MHz chroma (so does the phase alternation) so that a TV with a PAL 4.43Mhz decoder that can lock to both 525/59.94 and 625/50 input signals (which almost all TVs sold in Europe were capable of by the late 80s) can display a colour picture.

NTSC 4.43 VCRs didn't do the conversion from NTSC to PAL that PAL60 VCRs did, but instead just heterodyned the 627KHz NTSC chroma up to 4.43MHz instead of 3.58MHz (which was simpler as it removed the need for a pair of heterodyne circuits in the VCR for PAL and NTSC support, and avoided the TV/monitor displaying the signal needing both 3.58 and 4.43MHz chroma support).

NTSC 4.43 required the display to support NTSC decoding at 4.43MHz - which in some cases was easier to add to a PAL 4.43MHz display than NTSC 3.58MHz decoding support.

My 1993 and 1996 Sony CRTs both supported PAL, NTSC 3.58, NTSC 4.43 and PAL 60 - and my mid-90s Sony VCRs did too (I could chose between NTSC 3.58, NTSC 4.43 and PAL60 output from the VCR when it replayed an NTSC VHS tape). NTSC 3.58MHz definitely looked a bit better, NTSC 4.43 was marginally worse, and PAL 60 was worse still.

Colour Bar ID

NTSC & PAL/SECAM used diffrent colour/color bar test patterns and master tapes and some release copys of media will have these at the start and end of the tape to calibrate video monitors levels.

EBU PAL 75% Colour Bars	SMPTE NTSC 75% Color Bars

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