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Idea & Info Wanted: Dreaming of the ultimate LD transfer — Page 2

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A hot-wheel?

<span class=“Italics”>MeBeJedi: Sadly, I believe the prequels are beyond repair.
<span class=“Bold”>JediRandy: They’re certainly beyond any repair you’re capable of making.</span></span>

<span class=“Italics”>MeBeJedi: You aren’t one of us.
<span class=“Bold”>Go-Mer-Tonic: I can’t say I find that very disappointing.</span></span>

<span class=“Italics”>JediRandy: I won’t suck as much as a fan edit.</span>

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Heavy is good. After my 704 went south on me, (a cheap tiny little spring fell off the side changing gizmo the laser pickup rides on) I looked around at what could still be bought in DVD's atomic wake. One Pioneer model I almost bought open box was mind bogglingly light! I had lurid visions of it flying off the shelf trying to get an LD up to speed.
It pains me to think Pioneer went cheap ass before they gave up LD for good.
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Where were you in '77?

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OK so I exaggerated a little, but the sucker weighs in at 36Kg ( 80lbs ), so its no flyweight.
To paraphrase from the service manual.
The HLD-X0 has 37 active power regulators spread around its different PCBs, most of these are not the standard IC type but made from several individual components which has much lower impedance variations than the IC type. The HLD-X0 has in its NTSC path five NTSC decoders (from RF) in parallel to average out any decoding errors, it has enough memory to run NT, uses 9 bit digital processing, uses the best selection of 1702 audio DACs and so on. Its a real beast.
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Have you tried any rotted discs with it yet?
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Where were you in '77?

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Oh yeah, it cuts through them like butter. Old Discovisions that won't even play on a cld-97 play without a glitch on the X0.
Dunno why other players weren't made with the same laser assembly - I guess it was too near the end of LD.
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How 'bout this for blue-skying:

The laser assembly is just an input to some complicated processing, right? And even some of that complicated processing is just an input to some even more complicated processing. Part of that processing is feedback to the laser assembly (accel or brake, for example), and some is signal from the disc -- some sort of RF signal, which isn't yet video and audio so much as it is "proto"-video and "proto"-audio, to be turned into RGB/S-video/composite way down the line somewhere.

(You know where I'm heading with this, don't you?)

Could it be possible to build a Franken-X0 that would use the high-quality laser pickup and some of the early signal processing stuff of the X0, but be controlled (feedback, and latter signal processing) by something like the 925 or 2950's PAL section?

Now, assuming that it is possible -- I'm an optimist, but not an electrical engineer -- is it even remotely feasible?

I don't think anyone could argue that this would not be the best possible PAL player ever. Totally unique, and fearsome. Also maybe a waste of a good X0, perhaps, but unique and fearsome.
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I- T-S A - L - I - V -E !!!

Hmm FrankenX0, I highly highly doubt it, but who knows, it may be possible to adjust the X0 to read PAL disks anyhow if you left the soundtrack alone.
I'll have a chat to the boys downstairs in tech when I get back.

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Thus thread is exciting me and scaring me at the same time.

<span class=“Italics”>MeBeJedi: Sadly, I believe the prequels are beyond repair.
<span class=“Bold”>JediRandy: They’re certainly beyond any repair you’re capable of making.</span></span>

<span class=“Italics”>MeBeJedi: You aren’t one of us.
<span class=“Bold”>Go-Mer-Tonic: I can’t say I find that very disappointing.</span></span>

<span class=“Italics”>JediRandy: I won’t suck as much as a fan edit.</span>

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Well I'll continue my thoughts on moding it here then. Karyudo it appears even my electrical knowledge is more than yours. It does appear that you hit a hitch, though, as laserman says there are five independent NTSC decoders on board, which are then used together in the final output. I understand this complicates things for several reasons. My best advice for Laserman would be to mod a more expendable - but similar NTSC unit first, and see if it works. Yes your dummy unit won't have the same complications of the 5 NTSC processors, but it will provide a starting point.

Yes, there is no "tap here for pal" - but it's really not THAT complicated. It wants to process the picture it's read, all you have to do is feed it's information through the right circuitry in the right way. The first, and most obvious thing is the frequency, changing that is no problem. The only real problem is the fact there's no PAL processor on board to decode a PAL output. You may be able to coax the NTSC ones into it, however you'd still have an ntsc signal. Laserman I expect could explain this to you far better than I ever could, but basically the PAL standard features more stable hues, wider luminance bandwidth and a higher gamma ratio than NTSC. So, when I play an NTSC DVD on my home player I have it set to output PAL to take advantage of those features of the PAL signal system. It outputs PAL-60 instead of NTSC, which has the same number of lines as NTSC at the same frame-rate, but better colour and contrast. And it is visibly better on my TV. Fleshtones look much more consistent, NTSC likes to make fleshtones look too red.

Now if you play a PAL LD and output it in a hybrid 50hz NTSC signal, well you loose all the advantages of the PAL colour system. You lose the contrast definition, and the hue stability.
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For some guy just hypothesizing everything and without resources or even a player of your own, you're awfully condescending.

When you're done your transfer, DanB, be sure to let us all know.

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Karyudo I don't live under a dictatorship, and not certainly not one dictated by you. I haven't posted many replies lately because (to name names) MeBeJedi persists to hold a grudge. I have no grievance with anyone here, if they want - if you want to hold a grudge, then that is your choice. It's not that I don't care, but it is that my right free speech comes before your right to have everything your way on this forum. Laserman said here exactly what I was thinking in terms of modifications - either way I certainly don't expect the X0 to be modified; I was simply discussing the possibility irrespective of the availability, or practicality. You wondered if you could take the laser out and put it in another player, have you ever tried to replace the laser in a DVD drive with one from another drive?

It can't be done. Oh sure for some similar models from the same manufacture, yes... but two drives internally different with different laser assemblies? Nope. CD players? Not a chance.

"If I have my way, you will never, ever have a copy of anything I have the opportunity to work on."

It is exactly that kind of attitude which I take issue with. So you don't want what you work on to be publically available to all?

No, that isn't what you want is it? Come on, I know better than that - you must want the original Star Wars Trilogy to be publically available or you wouldn't be involved in anything. I have a friend, who agrees that the Special Editions are awful. However he likes the new Empire scene, and the sabre effects. That is to say, he prefers them. This kind of pick-and-choose attitude is what is detracting from the original trilogy preservation. How can one person say that the Original Trilogy is what should be available, but then when push comes to shove produce a Modified Trilogy? Is that Film Preservation?

Let me ask you, if this was the preservation of the original Noddy Books, would it be okay if instead of publishing the original books how they were originally released, I modified the images that bothered me? If I did that in my "preservation" what right would have to claim golliwog shouldn't have been edited?

It saddens me to see an intelligent individual as yourself become so. You don't have to see things my way to conduct in civil debate, or discussions. You don't have to hold a grudge either. I have seen the pains it causes, because one person - and it only takes one - refuses to get along with another. And don't you - OR ANYONE ELSE, dare roll that back on me, I have not marginalized any member here, I do not hold a grudge with anyone. What your quoted statement says to me is "you are not worth the time of day". Now I'm here to tell you now, that I do not feel that way about you, or any other forum member.

The reason I have taken pains to try and convince MeBe, is that when Lucas looks at this what he will see is people cherry-picking how to compile their own version of the trilogy. Heck he has even said himself that it's not the fans that should have it their way, it's him who should have it his way. And that's exactly what he's going to continue to think if we (the SW fan community) persist with editing his work. I agree with Lucas, it's not the fans that should have it their way. What I argue is for the original trilogy in the interests of film preservation. To have the movie released his original way.

And I do believe that what MeBeJedi will do with his version will undermine the efforts of having Lucas himself release the unaltered trilogy. I'm not finished. I'll post back shortly with an extension to this post.
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DanielB, I actually do agree with your views. I want an OT transfer without any fixed sabre shots. I also dislike the change of Gollywogs to Goblins, the removal of the gruesome end to Peter Rabbit's father, and the "dumbing down" of Awdry's Railway Stories.

It's just a shame you have to be such an annoying twat.

Now, back on topic:
There's something I don't understand in this discussion about playing the PAL discs on the NTSC-only X0, maybe Laserman, Karyudo or someone else could clarify. The video on a laserdisc is stored as an analogue waveform, yes? The optical stuff in the player converts the undulations on the disc surface to an electrical composite video signal. Why does the player need to decode this signal (if it's not doing any processing)? Isn't it the display device or capture card that decodes the composite signal into RGB? From my simplistic point of view, if the disc itself is PAL or NTSC then the output signal will be the same format. Or does the player need to decode the signal to check the disc is playing at the correct speed, or something like that?

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Moth3r thankyou. I will forget you called me an annoying twat, and I will not use name-calling myself.

The simple answer to your question is the decoders are poorly named, like how positively charged electricity is the lack of electrons. It should be called an encoder. Well that's my understanding anyway, I may be wrong.

-edit-

I might add to Karyudo, thankyou for removing the insults from your post. I have no grievance with you, please do not hold a grudge against me.
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It's pretty obvious here that some of you know almost nothing about how laserdisc works, and are assuming that it is like CD or DVD which is not the case.
You need to get away from the 'digital' mindset, that the data is just read of the LD as some info which is then simply output ot PAL or NTSC. This is not how laserdisc works. I don't mean to sound mean, but suggestions without any knowledge or research are mostly wasted as the reality is so complex that the chance of 'stumbling' across a solution is almost infinitely small. I'd suggest anyone wanting to contribute to the Franken-X0 discussion do some reading and research offline first.

Some background will probably be helpful here.
1) PAL vs NTSC. Its not just the framerate. The big differences as far as laserdisc goes are:

a) Different rotational speed. NTSC CAV = 1800RPM PAL CAV=1500RPM NTSC CLV = 1800 down to about 600RPM, PAL CLV = 1500 to about 500RPM

b) 3:2 Pulldown. This is where it gets frankly amazing. You all know that for NTSC they do the perverse 3:2 pulldown, wherin you use a film frame for the first 3 fields, then grab the next frame and use it for 2 fields, and then start again. (Grabbing the next frame is referred to as 'pulling it down' hence the 3:2 pulldown name. They used to just repeat the 4th frame which gives the awful juddering you can see on some early telecines.
Now to do this on Laserdisc, they player has to know which two adjacent fields actually make up the frame (othewise you might get one field from one frame of film, and the other field from a diferent frame - not good). So how does an analogue system cope with this? Easy, encode the required information in the VBI (the vertical blank interval). When making the disc, you store the info in the VBI, its often referred to as a 'white flag'. When you hit the pause button on a CAV disc, it reads the flag, and the laser assembly actually does a one track reversal (i.e. 2 fields) and can then redisplay the current frame. It is set in the VBI area outside of picture info, or CC info (its at line 11 or 274 depending on the field). If you get it wrong, the pause feature will have a 'jiggling' frame for 40% of the frames! You can see this on some discs. Sometimes just the 'picture number' is used instead, which is also encoded into the VIL.
PAL on the other hand needs none of this, they just play at 25fps, like the way DVD does in that respect. This makes PAL very attractive for conversion as there is no difficult IVTC to contend with.

c) Frequency and colourburst. The frequency of PAL is 50Hz, and of NTSC 60Hz (for this discussion anyway). Laserdiscs are composite video, which in simple terms means a black and white image with a colourburst signal. Even black and white laserdiscs have to contain the colourburst signal. The colourburst signal from PAL and from NTSC are also very different, and because of PAL's encoding, there is no need for the 'hue' adjustment you see on NTSC TVs. On PAL , red is just red - end of story.

d) Analogue Video. Video is stored on the laserdisc on one long spiral of pits of infinitely variable length (the analogue part). For NTSC the baseband CV signal of around 4.2MHz wide is used to modulate a FM carrier signal (about 8.5MHz or so) . This results in a variable amplitude of 7.5Mhz to 9.3MHz, which gives you an analogue rendition of video (Its at this point that it is something near video, but still not something you could directly output to a TV) . It is not digital video, so what is on the disc is not anything that is directly manipulatable or 'interceptible' to turn it from NTSC to PAL.
Now because it is *not* digital, it is actually possible to swap laser transports between different models, and this has actually been done in the past. It also means that laserdiscs are weird and wonderful beasts with analogue braking mechanisms, and all sorts of amazingly bizarre mechanisms to track the spiral and focus etc. They are absolutely not anything like a CD player in that regard, and the video extraction is absolutely not like DVD or VGA - TV for example.

d) Resolution. This is where it gets really interesting for us. In letterbox mode, NTSC discs have a vertical resolution of just 480 vs PAL 576 lins. This may not seem a big deal, but when ou get down to letterbox, that leaves NTSC with a measly 272 lines of resolution! PAL by contrast has 327 available lines (obviously depending on the aspect ratio, but the above is pretty much what you get on Star Wars), so around 20% more. When the baseline is so low this can really make a difference - hence the interest in the PAL laserdiscs as a master.



Now in NTSC laserdiscs, there is no error correction, unlike DVD, so the means of making sure you get a watchable picture are purely analogue. On the X0 for instance, there are multiple output stages to average out any errors, on other players they employ a range of techniques to get a decent picture out the other end.

They are a truly fascinting system, but also horribly horribly complex, and take a non-digital mindset to understand them They actually have a lot more in common with VHS than they do with DVD or CD as far as the video goes.
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Yes I can see what you're saying, that's some very useful info LM. I did not realise that Laserdiscs repeated frames for pulldown, I thought that they'd just encode the repeated field twice. I had not initially thought of the rotation speed, however for NTSC TV material that is native 30fps (and so every field is encoded), does that require a different rotation speed? From what I now know I would say modding the X0 for PAL output is impractical.
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Originally posted by: Laserman
It's pretty obvious here that some of you know almost nothing about how laserdisc works, and are assuming that it is like CD or DVD which is not the case. You need to get away from the 'digital' mindset, that the data is just read of the LD as some info which is then simply output ot PAL or NTSC. I've never cracked a LD player open, and even if I had I wouldn't know what I was looking at. However, I've never had the 'digital' mindset; I've always thought of an LD player as the video equivalent of a record player, in that a vinyl record, like LD, contains uncompressed analogue information. That simplistic analogy has been sufficient for me up until now, but I was requesting for further clarification from yourself or Karyudo as to the nature of the signal stored on the disc.

Originally posted by: Laserman
This is not how laserdisc works. I don't mean to sound mean, but suggestions without any knowledge or research are mostly wasted as the reality is so complex that the chance of 'stumbling' across a solution is almost infinitely small. I'd suggest anyone wanting to contribute to the Franken-X0 discussion do some reading and research offline first. Well this thread was never intended to offer a real solution, it was based on my "dreaming of..." or "wouldn't it be good if...". I had no idea that such a project was actually in the running! But modifying an existing X0 player to play PAL disc goes beyond even what I thought would be the "ultimate" transfer.

Originally posted by: Laserman
Some background will probably be helpful here.
Yes, that info is helpful, thank you.

Originally posted by: Laserman
d) Resolution. This is where it gets really interesting for us. In letterbox mode, NTSC discs have a vertical resolution of just 480 vs PAL 576 lins.

This may not seem a big deal, but when ou get down to letterbox, that leaves NTSC with a measly 272 lines of resolution! PAL by contrast has 327 available lines (obviously depending on the aspect ratio, but the above is pretty much what you get on Star Wars), so around 20% more. When the baseline is so low this can really make a difference - hence the interest in the PAL laserdiscs as a master.
On my PAL version of ANH it's 320 lines. On ESB and ROTJ, it's 324 lines.

However, the 20% increase is not always that clear cut, because telecine machines filter the fine horizontal detail to prevent flicker when displayed on an interlaced display. If the PAL discs were subject to the same level of filtering as the NTSC discs, then there would be no benefit from the extra resolution! I don't know if this is the case or not, and I don't have the NTSC discs to do a direct comparison.

EDIT - well, Karyudo has the resources to do a direct PAL/NTSC compare. I think it would be in our interests if he would be kind enough to make some screenshots for us.

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