Question about PAL vs. NTSC

[Dayspring]

Hi there,

I have a question about TV systems. This might be akin to asking for a philosphical debate, but I was wondering which system people think is a better system: NTSC, or PAL?

I mean, I suppose they must both have their own weaknesses and strengths, and certainly you're more or less stuck with whichever system is available in your area. But overall, which do you think is the stronger system...?

Just offhand, I suppose the basic difference is between a higher vertical resolution vs. higher refresh rate. Is there more to it than that? I'm interested in people's opinions.

Thanks,
Matt

[This message has been edited by Dayspring (edited 22 March 2000).]

[fluggo99]

Though I don't use it, I see the PAL system as far more practical. It matches the frame rate of the films made in those countries, and 25 fps is certainly acceptable if films on this side of the ocean are OK at 24 fps.

NTSC doesn't even have a round number for a frame rate.

[Michel Carleer]

If I remember correctly, PAL not only has a better vertical resolution (625 versus 525 lines), but it also has a better horizontal resolution because of the higher bandwidth (6MHz versus 5.5 ?)
As for the frame rate, the non-round number comes from the frequency of the color sub-carrier. The 3.54 MHz was chosen because of availabilty and stability of synthesizers at that frequency. On the other hand, the color frequency has to be a x and a half multiple of the horizontal frequency (15750 Hz) in order to minimize crossover between luminance and chrominance signals.
Beware, I read all this some 25 years ago, so I am telling all this from ... What is the word again? ... Ah yeah! Memory.
Michka

[salacious]

PAL in different regions sometimes has different bandwidths so it is always true about horizontal resolution.
In the UK where the colour carrier is 4.43MHz this gives you slightly better resolution before interference start occuring between the luminace and chrominace information. PAL uses phase alternative line (hence it's name) and what this does is to remove any errors in the chrominace signal by sending the chrominance over two lines with different phasors and the phasors cancel out when added together and you are just left with the chrominace signal.
The effectively removes the Hue option from your TV since you don't need it. The only downside is that it actually reduces the vertical chrominace resolution but since our eyes are less susceptable to chrominace information we tend not to notice.

I like fluggo99 joke about framerate of PAL country films. ALL films (except IMAX) are shot at 24fps. In the US to get to 29.97fps you use 3:2 pull down with drop frame. In the UK to get 25 fps, we speed up the films by 4% (25/24) which has the side effect of increasing the audio by a semi-tone which isn't always corrected. I have heard of people complaining about Pink Floyd - The Pulse on LD since the music is a semi-tone higher. Also on old video tapes of Star Wars, James Earl Jones voice was a semi-tone higher so you lost a little of his VERY deep voice.

Salacious

[This message has been edited by salacious (edited 23 March 2000).]

[Michel Carleer]

Salacious,
What is the bandwidth of the UK PAL standard?
All PAL european countries use the same 4.433619 MHz color carrier but I think the UK uses a different sound subcarrier than Germany, the Netherlands, Belgium, ... Or is it that you use AM modulation versus FM? There is a difference with sound which makes the TV sets different between the continent and the rest of Europe.
Michka

[fluggo99]

Coulda sworn foreign films were made at 25 fps; oh, well. My bad. (Geez, I'm gettin' a whole slew of these things wrong lately...)

[salacious]

The total video bandwidth is 6MHz for UK PAL. Some other European PALs bandwidth is only 5.5MHz. The are different versions of the PAL standard called things like PAL I, PAL M, PAL G etc these differ with a soundcarrier being on different frequencies. Most of Europe uses PAL Bor PAL G where Britain uses PAL I. In the UK sound is FM whereas in France which have SECAM-L with AM sound. NICAM sound is also encoded above the video spectrum at 5.85MHz on european PAL and at 6.552MHz on UK PAL. I have a book at home which tells me all this at home. I will check up the details to make sure I haven't confused things.

In some countries (I think Brazil is one) they have merged the PAL and NTSC standards to get things like 625/60, 525/50 and colour carriers all over the place.

Salacious

[Michel Carleer]

Thanks Salacious.
Anyway one big problem with the RR-G or the Marvel is that their deinterlacing algorithm is, I believe, well adapted to the kind of resolution they have in the US (NTSC). But in Europe (PAL or SECAM) it tends to blur the picture really too much. In my PC I have both a Marvel G400 and a Pinnacle (Miro) PCTV. The PCTV does not deinterlace the picture at all, so that interlacing effects can be seen, but on the other hand the sharpness of the picture is by far superior. If I look at any european channel with the Marvel, I have the impression I am looking at CNN and it's poor US resolution. Sorry fellows, but NTSC favoured a higher refresh rate at the expense of picture resolution, that's a fact. Unfortunately, Matrox does not give us the choice to switch off or lower the amount of deinterlacing. This is a major default in the way Matrox write their programs: Why is it that when you choose to capture in RGB format you only have the choice of NTSC picture resolutions (320x240, 640x480, ...) whereas for MJPEG you only get the PAL 352x288, 704x576, ...??? The hardware is capable of all resolutions both in RGB and in MJPEG. So why deliberately cripple their card by software? Also, the hardware is capable of capturing in several YUV formats, but you can't choose them in the video tools. After all, YUV is the native digitizing format, and to capture in this format you don't have to do any transcoding, contrary to RGB or MJPEG capturing. Why disable it? I don't understand this way of thinking. One additional rant: in most european countries, we can receive TV from several different countries; which means (apart from the many video formats) receiving channels emitting mono sound, stereo sound, NICAM sound, or multilingual sound. Why is it that I have to go to a child window of a child window of a child window of ... in order to choose between these different audio formats (righ click on the VT, choose Properties in the drop down menu, click on Advanced, choose the Audio tab, select the audio format and finally select mono or stereo). To be fair, most video cards you can buy more or less suffer from the same problem of very good hardware crippled down by really poorly thought (and written) software. Unfortunately Matrox goes a long way in this direction, probably thinking that diminishing the number of choices makes the software easier to use. This is wrong thinking, there are ways to write an interface so that it is both easy to use and at the same time enables you to exploit the full possibilities of the hardware. Matrox programmers: take a look at the Pinnacle PCTV software: It is capable of finding ALL channels, even the ones that are out of the correct frequency; it can automatically detect and switch to the correct audio format, it automatically gets the name of the channels from the VBI information, and so on. Let's hope the next release of the video tools will correct some of this, but I am afraid Matrox still has a long way to go.
Michka

[Meek]

One thing where PAL is a bit better than NTSC is color fidelity. The clever use of Phase alternation eliminates the hue shifts that NTSC has been plagued with.

Of course, currently the differences are not that big, as technology in eliminating the hue problems in NTSC are everywhere.

M.

[Brian Ellis]

Meek

We have had the explanation of what PAL means. Are you saying NTSC means Never Twice the Same Colour?

I have just returned from the USA and what I could see on TVs in my hotel rooms does not compare favourably with ditto in Europe. Especially now that most European sets (other than the cheapest) now have a field rate of 100 Hz (keeping each field in memory and playing it twice, some even interpolating between successive frames), which has eliminated the flicker which was occasionally visible on bright images.

------------------
Brian (the terrible)

[salacious]

NTSC really stands for Natinal Television Standards Committee.
I personally aren't a fan of 100Hz TVs. To do 100Hz you have to build a picture inbetween the current pictures. On older 100Hz TV sets the artefacts were awful, now they are almost acceptable but it does meant it doesn't work with my Playstation lightgun. Damn.

Salacious