[MrWibble]

Originally Posted by london-boy

I know, but some players do. Not sure what the end result is though.
Most PAL TVs are perfectly fine with NTSC signals these days so R1 DVDs are a non-issue really.

Most TVs are fine with 60Hz signals, less are fine with actual NTSC. There were quite a lot of people complaining about 60Hz support in PS2 games not working properly (i.e. being black & white) where other consoles had worked fine. Largely because most things output PAL-60 whereas the PS2 outputs real NTSC (unless you do something naughty).

Not an issue if you're not using something better than composite video, because with a better connection PAL and NTSC distinctions are largely irrelevant and it's only the resolution and refresh to worry about

From next year we'll have a new and improved list of issues to worry about, with HDTV resolutions to choose from, and the resolutions themselves being either at 50Hz or 60Hz, which is still unclear at the moment - Sky will broadcast in 50Hz but i assume consoles will output at 60Hz... And the problem is that some HDTVs sold in the UK these days only accept one of the 2 refresh rates...

What a mess... We'll have a total of 10 configs... 480i/p/50/60, 720p/50/60, 1080i/p/50/60...

1080 is worse because there is a 24fps variant for film usage to avoid frame-rate conversions... though my assumption (read as: I don't know what I'm talking about here) is that this is for the content, not the output/screen...

However the labelling of "HD Ready" devices can only be done if the screen actually accepts *both* 50 and 60. So although right now it's a bit of a mess, I think the majority of devices in peoples homes will be ok. Right now I suspect that most people who have newish HD sets are early-adopter types who could well upgrade again anyway.

A small few might find themselves with what they thought was an HD TV but which only works with a selection of HD content. That's a bit of a shame but hardly surprising when manufacturers rush things to market prematurely and people buy them without really understanding what it is they're getting. Caveat emptor, and all that.

But it's a bit of a mess and could so easily have been avoided if it wasn't for those pesky broadcasters and all their legacy 50Hz equipment and content...

You can never have enough standards!

[Shifty Geezer]

Originally Posted by MrWibble

1080 is worse because there is a 24fps variant for film usage to avoid frame-rate conversions... though my assumption (read as: I don't know what I'm talking about here) is that this is for the content, not the output/screen...

Hang on! This sounds like crazy talk. There'll be 24 fps content on 1080 film disc, which'll be shown on 50 and 60 Hz progressive sets. So there'll be some temporal scaling to show these, on the player? Different sets will play the same program at different speeds? Or the player? Must be the player as it has no idea what it's connected to. What about when you have one player linked up to multiple TVs and they're not all 50 or 60 Hz? How can you have output of a DVD at 24 frames per second and show it at the same speed on 50 and 60 Hz sets if one format just does one frame per two fields at slightly faster then real speed, and the other does interleaved frames slightly slower than real speed, but the disc is sending data at the same rate anyway.

That doesn't make sense to me.

[london-boy]

Originally Posted by Shifty Geezer

Hang on! This sounds like crazy talk. There'll be 24 fps content on 1080 film disc, which'll be shown on 50 and 60 Hz progressive sets. So there'll be some temporal scaling to show these, on the player? Different sets will play the same program at different speeds? Or the player? Must be the player as it has no idea what it's connected to. What about when you have one player linked up to multiple TVs and they're not all 50 or 60 Hz? How can you have output of a DVD at 24 frames per second and show it at the same speed on 50 and 60 Hz sets if one format just does one frame per two fields at slightly faster then real speed, and the other does interleaved frames slightly slower than real speed, but the disc is sending data at the same rate anyway.

That doesn't make sense to me.

Just go with the flow Shiftster... Don't try to understand the intricacies of PAL HDTV, just... Embrace them...

[MrWibble]

Originally Posted by Shifty Geezer

Hang on! This sounds like crazy talk.

...

That doesn't make sense to me.

Note the bit where I quite happily admit I don't know the details of this particular aspect...

However AFAIK it's used in production - I've no idea if it's ever been used or is intended for distribution either broadcast or on disc.

What I have encountered is people who think that 1080p is 1080p/24... so even if it's not relevant in this context, it's causing even more confusion.

[hongcho]

Hmm...

I think the confusion is coming from how the term "interlaced" as expended to include "segemented frames".

In analog days, interlaced video ("i") meant that two frames (odd lines and even lines) that make up a frame comes from two different time instances. This is where the de-interlacer comes about and probably the most analog broadcasts are in this format still.

Then came the digital tools (more precisely the progressive displays). With the advanced technology, we can now scan the whole frame at once ("p"). However, most of the broadcasting tools only new interlaced (and most TVs were interlaced). So, they came up with something called "segmented frames" ("sF").

This is not exactly "interlaced", but it takes a frame and split into two fields (so, these two fields come from the same time instance). This is essentially a progressive image, just format into two fields so that all the editing and other broadcasting tools can handle it.

Due to this history, some people say "interlaced" when they mean "segmented frame" as well.

So, in the analog broadcasting world, the interlaced video still have two fields that come from two different time instances. But in the digital broadcasting and computers, it's mostly either progressive or segmented frame.

Anyway, why are we talking about broadcasting technologies?

Hong.

[Shifty Geezer]

Originally Posted by london-boy

Just go with the flow Shiftster... Don't try to understand the intricacies of PAL HDTV, just... Embrace them...

It's freakin' me out man! Japan is Region2, NTSC. UK is Region2, PAL. I can get a Japanese DVD, plug it in my DVD player and watch it (in theory), but at what speed on the TV? I'm really curious now. I want a DVD player, Japanese DVD, and output to two TVs, one PAL and one NTSC and run them. In theory, if PAL runs a little quicker, I'll have finished watching the film on the PAL set before the NTSC set, despite reading the same data at the same rate from the same player.

Still, though this sounds confusing I guess a calming solution can be found in a quantum physics explanation. Something involving infinit paralell dimensions would explain this behaviour nicely.

[MrWibble]

Originally Posted by Shifty Geezer

It's freakin' me out man! Japan is Region2, NTSC. UK is Region2, PAL. I can get a Japanese DVD, plug it in my DVD player and watch it (in theory), but at what speed on the TV? I'm really curious now. I want a DVD player, Japanese DVD, and output to two TVs, one PAL and one NTSC and run them. In theory, if PAL runs a little quicker, I'll have finished watching the film on the PAL set before the NTSC set, despite reading the same data at the same rate from the same player.

PAL doesn't inherently run quicker. Movies *converted* to 25fps for playing on PAL equipment run quicker than movies converted to 30fps. If your player is playing it back, it's only going to do that at one rate at any given time, no matter how clever it is. A lot of the time the content is preconverted to the appropriate framerate for the region it'll be sold in.

Chances are your R2 Japanese DVD would play back at 60fps (actually, 59.94 if you want to be really anal about it).

What you *could* do, if you want to see the effect, is get the same movie in both PAL and NTSC variants and run it on a native player side by side, and you'd see them go out of sync - quite dramatically by the time a couple of hours have passed.

Another thing that happens surprisingly often is that sound goes out of sync with video. You see it a lot on PC based movie players and happens despite the two streams being interleaved into one source of data. The video gets decoded at "roughly" the right rate, but the sound is output consistently at the correct rate (because frankly sound hardware seems a lot more consistent), and as the two are buffered differently they can diverge. Sometimes you'll see a player stuttering on the video to allow the audio to catch up with the video.

Ironically game content tends to be the other way around, if a developer locks to the framerate and doesn't correct for regional differences, the PAL version will be slower.

Still, though this sounds confusing I guess a calming solution can be found in a quantum physics explanation. Something involving infinit paralell dimensions would explain this behaviour nicely.

It would probably be easier to understand, too.

[Phil]

Originally Posted by MrWibble

Another thing that happens surprisingly often is that sound goes out of sync with video. You see it a lot on PC based movie players and happens despite the two streams being interleaved into one source of data. The video gets decoded at "roughly" the right rate, but the sound is output consistently at the correct rate (because frankly sound hardware seems a lot more consistent), and as the two are buffered differently they can diverge. Sometimes you'll see a player stuttering on the video to allow the audio to catch up with the video.

I actually can confirm that - there were quite a few Sony players that suffered from this and had to be fixed because the audio and video would fall out of synch after some time. Pausing the player manually would solve the problem....

Thanks for pointing out about the speed ups - I didn't know that, but knowing that now, it explains a lot why the problem of audio synching even existed!

[[maven]]

Originally Posted by MrWibble

60fps (actually, 59.94 if you want to be really anal about it)

"59.94 Hz is only a conventional approximation; the mathematically exact field rate is 60 Hz * 1000/1001."
from http://www.uwasa.fi/~f76998/video/conversion/

Sorry...

[Simon F]

Originally Posted by [maven]

from http://www.uwasa.fi/~f76998/video/conversion/

The pop you just heard was the sound of my brain exploding from information overload.