The TV industry is dominated by two main standards for TV design: PAL and NTSC. NTSC is one of my pet hates basically because
of it's rather low quality and use of weird framerates. NTSC stands for the National Television Systems Committee,
it is the colour video standard used in North America, Canada, Mexico and Japan.
Some engineers have said it should stand for Never Twice Same Color
because no two NTSC pictures look alike
.
Due to the electric system used in the US it was decided to scan the lines across the NTSC TV screen at about 60Hz
(or 60 half frames per second) which produced 30 whole pictures every second. NTSC resolution is about one sixth less than that of PAL.
This may not seem so bad, but divide a sheet of paper into six even parts and chop one off of the bottom and
you will have a lot of detail lost. NTSC uses 525 horizontal lines of which only about 487 make up the active picture.
PAL stands for Phase Alternating Line, it is the TV standard used for Europe, Hong Kong and the Middle East.
It was a new standard based on the old NTSC system but designed to correct the NTSC colour problems produced
by phase errors in the transmission path. PAL resolution is 625 horizontal lines but only about 540 of these are used for the picture.
PAL is higher quality than NTSC, it keeps a sharper picture and remains closer to the original format produced by
motion picture cameras. Due to the European electric standards it was decided to interlace PAL lines every other line at
50Hz producing 25 whole frames every second.
http://www.dvddemystified.com/dvdfaq.html#1.19
[1.19] Is DVD-Video a worldwide standard? Does it work with NTSC, PAL, and SECAM?
The MPEG video on a DVD is stored in digital format, but it's formatted for one of two mutually incompatible television systems:
525/60 (NTSC) or 625/50 (PAL/SECAM). Therefore, there are two kinds of DVDs: "NTSC DVDs" and "PAL DVDs."
Some players only play NTSC discs, others play PAL and NTSC discs. Discs are also coded for different regions of the world (see 1.10).
Almost all DVD players sold in PAL countries play both kinds of discs. These multi-standard players partially convert
NTSC to a 60-Hz PAL (4.43 NTSC) signal. The player uses the PAL 4.43-MHz color subcarrier encoding format but keeps
the 525/60 NTSC scanning rate. Most modern PAL TVs can handle this "pseudo-PAL" signal. A few multi-standard PAL
players output true 3.58 NTSC from NTSC discs, which requires an NTSC TV or a multi-standard TV.
Some players have a switch to choose 60-Hz PAL or true NTSC output when playing NTSC discs.
There are a few standards-converting PAL players that convert from an NTSC disc to standard PAL output for older PAL TVs.
Proper "on the fly" standards conversion requires expensive hardware to handle scaling, temporal conversion,
and object motion analysis. Because the quality of conversion in DVD players is poor, using 60-Hz PAL output with
a compatible TV provides a better picture than converting from NTSC to PAL. (Sound is not affected by video conversion.)
The latest software tools such as Adobe After Effects and Canopus ProCoder do quite a good job of converting between
PAL and NTSC at low cost, but they are only appropriate for the production environment (converting the video before it is
encoded and put on the DVD). See Snell and Wilcox's The Engineer's Guide to Standards Conversion and
The Engineer's Guide to Motion Compensation for technical details of conversion.
Most NTSC players can't play PAL discs. A very small number of NTSC players (such as Apex and SMC) can convert
PAL to NTSC. External converter boxes are also available, such as the Emerson EVC1595 ($350).
High-quality converters are available from companies such as TenLab and Snell and Wilcox.
Many standards-converting players can't convert anamorphic widescreen video for
4:3 displays. See 1.22.
There are three differences between discs intended for playback on different TV systems: picture dimensions
and pixel aspect ratio (720x480 vs. 720x576), display frame rate (29.97 vs. 25), and surround audio options
(Dolby Digital vs. MPEG audio). (See 3.4 and 3.6 for details.) Video from film is usually encoded at 24 frames/sec
but is preformatted for one of the two required display rates. Movies formatted for PAL display are usually sped up
by 4% at playback, so the audio must be adjusted accordingly before being encoded. All PAL DVD players
can play Dolby Digital audio tracks, but not all NTSC players can play MPEG audio tracks. PAL and SECAM
share the same scanning format, so discs are the same for both systems. The only difference is that SECAM
players output the color signal in the format required by SECAM TVs. Note that modern TVs in most SECAM
countries can also read PAL signals, so you can use a player that only has PAL output. The only case in which
you need a player with SECAM output is for older SECAM-only TVs (and you'll probably need a SECAM RF connection, see 3.1).
A producer can choose to put 525/60 NTSC video on one side of the disc and
625/50 PAL on the other.
Most studios put Dolby Digital audio tracks on their PAL discs instead of MPEG audio tracks.
Because of PAL's higher resolution, the movie usually takes more space on the disc than the NTSC version. See 3.4 for more details.
There are actually three types of DVD players if you count computers.
Most DVD PC software and hardware can play both NTSC and PAL video and both Dolby Digital and MPEG audio.
Some PCs can only display the converted video on the computer monitor, but others can output it as a video signal for a TV.
Bottom line: NTSC discs (with Dolby Digital audio) play on over 95% of DVD systems worldwide.
PAL discs play on very few players outside of PAL countries. (This is irrespective of regions -- see 1.10.)
BTW :
I am currently running a DVD conversion PAL -> NTSC, using
http://www.pegasys-inc.com/en/product/te3xp.html,
and after 8 Hrs 49 Min, it has reached 51%
and is
finally on the 2. and last pass.