I'm not sure on the relevance of this post. I've given data showing the encoding of the raw MPEG streams on both R1 and R2 discs & these seems to follow NTSC and PAL resolutions and frame rates.
If a dvd disc was simply encoded in some base form and transcoded by the player then why do multiregion dvd players output NTSC or PAL depending on the region of the disc rather than simply transcoding to PAL or NTSC by default.
If OTOH, your point is that NTSC and PAL are RF transmission methods (as John has said) and aren't used to describe encoding methods then you certainly haven't made it very clearly and are IMHO being a little pedantic.;)
One point has been overlooked in this thread, there is also the question of how the material on the disc has been digitised. If it has been encoded to CCIR 601 standard, then it is by *definition*, PAL encoded isn't it ;)
I know that my multi-region DVD player produces some form of NTSC-alike output with R1 discs, because the geometry is different and can be seen to change when accessing the tv menu and fiddling with the 60Hz settings. Of course, it could be no more than PAL at 60Hz. I can't detect any obvious quality differences between R1 and R2 discs, and certainly don't have versions of the same disc to compare anyway.
The link I posted earlier from
formatting link
seems to suggest quite strongly that the frame rate of the encoded mpeg stream is the intended rate. As such, it is probably a good thing that R1 discs carry an NTSC logo if they are encoded at 30Hz (or seemingly 29.97 as the Yanks seem to have come up
0.1% short somehow), even if it is strictly technically meaningless. If my TV did not have some 60Hz capability, would I have to rely on my DVD player to drop frames to get down to 25Hz frame rate, assuming it could ?
[Okay, just checked the DVD manual. For output, it has PAL/Auto. on Auto, the TV must be multi-standard. I changed it to PAL and tried to play an R1 disc. Up popped a message saying it wasn't a PAL disc. Not quite the correct terminology, but I see what it meant.]
I don't think I've made myself clear. These might well be the common rates used on most PAL and NTSC, but this is due to history, not a fundamental.
They don't. They will output a native screen resolution and size etc, but this is nothing to do with PAL or NTSC.
They're not just transmission systems - they used to be part of the entire chain from camera output onwards. But this was many years ago with quality equipment. The PAL 'footprint' caused many problems in production and was dispensed with as soon as was practical. It only really exists now for the final stage of transmitter to receiver if things are being done correctly.
PAL is made up of 25 frames, or images per second, with *625* scan lines NTSC is made up of 30 frames, or images per second, with *525* scan lines
(and with both these each frame is displayed in two separate fields which are interlaced at either 50Hz (PAL) or 60Hz (NTSC) )
Errr - not necessarily ;-)
The DVD contains information that will instruct the player to render the digital data stream into an appropriate format. The actual data held on the disc can be format agnostic.
The problem with NTSC/PAL colour incompatibility is usually only observed with a composite or RF modulated video signal. This is because the chroma sub carrier information is positioned differently in an NTSC broadcast signal, and does not have a "swinging colour burst" like PAL. Hence the TVs failure to decode the chroma information correctly. If your TV has a RGB compatible input the whole thing gets much simpler.
Colour information in a video signal is not carried on "extra lines" as such - so fewer lines does not equal no colour. Also since PAL has a higher resolution than NTSC this would not support the argument!
A second and more important point is that when a DVD player is connected via a RGB connection you are no longer dealing with either PAL or NTSC video as such. RGB does not use a colour encoding scheme at all - the colour information is directly represented by the three R, G, & B wires.
Normally if you play a region 1 DVD, the player will output its RGB signal at the same scan rates as those used for NTSC broadcast. If your TV has RGB but is not capable of syncing to a 60Hz 525 line signal then you may also have a problem (although complete lack of picture or a rolling picture is more likely)
pardon me for replying to my own post... having read what I wrote I realalise that I do not write quite what I thought! ;-)
The word "format" was perhaps a little "fuzzy" for the pedantry of this conversation!
I should have added that while the colour transmission system of the actual data on the disc does not *have* to be encoded specifically for a given region - the digitisation is usually performed at a resolution and frame rate that matches that used in the target market.
So for example a region 1 DVD will be encoded for 30/60 Hz field/frame rate. The player however could output this in true NTSC, or as PAL60
(Its much harder for a player to change the frame rate of a disc however unless it includes a standards converter)
NTSC and PAL were originally systems to encode colour information in analogue video systems. Incidentally, PAL (Phase Alternate Line) was better, as it reverses the direction of the chroma signal every line. If the chroma adjustment is out, the colour divergence is opposite on every line, which cancels out, unless you press your face against the screen. This is why NTSC sets often has a colour adjustment knob, as it is far more critical to get the decoding right. Anyway, I digress.
As systems spread through the world, basically it divided into two main camps. Firstly the 625 line PAL 50Hz camp and the 525line NTSC 60Hz camp (with the addition of France, the Russians and satellites who pretended to use SECAM). It mostly followed the mains frequencies used in the various countries. However, PAL and NTSC aren't limited to the normally used framerates and resolutions. It is possible to have PAL at 60Hz with 525 lines. It is possible to have NTSC at 50Hz. Some countries had unusual systems. Few agreed where the sound carrier would go.
In any case, now in the digital age, PAL and NTSC have actually mutated to just become shorthand for a particular set of framerates and resolutions that were commonly used with the old analogue systems and no longer have anything to do with the encoding or colour system at all. At least, unless you are talking about analogue composite video signals.
I suspect the transformation occured because some ignorant people thought that NTSC/PAL referred to the resolutions typically used, rather than the colour encoding system. Their original proper meanings are actually more akin to the "MPEG" encoding part than the resolutions or framerates stated.
The regional coding is part of the operating system of the DVD which is purely in the digital domain. It matters not one jot whether it is to be replayed on a machine that delivers it in PAL or NTSC - that encoding is done in software and/or by the modulator.
Y'know, I always thought the crap on the disks about PAL/NTSC was just that, but my home cinema buff colleagues were insistent, so I just shut up, but it always struck me as insane to tie the disks to a TV system.
ITU-R Rec. BT601 (to use the full up-to-date title) is a standard for sampling and digitisation of video in _component_ form (i.e. with separate luminance and colour difference channels - Y, Cb, Cr). The whole shooting match was designed to simplify the process of exchanging material between
625/50 and 525/60 countries and the luminance sampling rate (13.5 MHz) was chosen to be compatible with both - it's 864 times the horizontal scan frequency for 625/50 systems and 858 times for 525/60.
Colour pictures can, and do, now go all the way from the studio to your CRT without going through PAL or NTSC codecs at all - and very much better they are for it too (provided that MPEG compression isn't overdone).
Of course DVDs aren't PAL or NTSC. These are now obsolescent analogue colour coding systems which were designed to bolt colour on to the luminance waveform in a compatible-ish manner, using a QAM sub-carrier. But they will be either 625/50 (720x576) or 525/60 (720x488). If you care about picture quality then the last thing you want to do is to turn 'em back into PAL (or NTSC) - so use RGB all the way to the tube if possible (with the half-way house, S-video, as second choice). Composite and modulated RF outputs _are_ PAL or NTSC and are clearly inferior.
720x576 @ 25 FPS is the PAL standard, used on PAL systems
720x480 @ 29.97 FPS is the NTSC standard used on NTSC systems
The origanal poster had problems playing DVD's on an old TV, this TV may not have supported the NTSC standard, therefore he got a black and white picture.
Maybe the wording should have been a NTSC format DVD, rather then just a NTSC DVD
Either way, DVD's ARE different, Some use the PAL fomat (720x576 @ 25 FPS) Some use the NTSC format (720x480 @ 29.97 FPS)
Are you happy with that statment, or are you going to tell me it is incorrect without explaining why, like you did in the first place?
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