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SmitdoggAdministrator
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DU: The great laserdisc flood
#376106 - 05/12/18 08:39 PM Attachment: DdD-PCB-2_2.jpg 448 KB (1 downloads)




Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which we're getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

[ATTACHED IMAGE - CLICK FOR FULL SIZE]

Attachment



CiroConsentino
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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376107 - 05/12/18 10:09 PM


Cool. What video format can be expect ? MPEG-2, AVI, MPEG-4, AVC, DivX, Xvid...



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SmitdoggAdministrator
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Re: DU: The great laserdisc flood new [Re: CiroConsentino]
#376108 - 05/12/18 10:11 PM


As far as I know those details aren't figured out yet.



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376109 - 05/12/18 11:35 PM


> Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which
> we're getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

This is so cool. I can't wait to hear the specifics of how the video data on these is being dumped. Looking forward to reading about it in the future!



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376110 - 05/12/18 11:36 PM


That's great! A long time ago (like ten years?) I sent off some LDs to be ripped and I figured they just disappeared into the void. Hopefully they are still around with someone involved - I'd be happy just to see Time Traveler or Badlands working in MAME.



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Re: DU: The great laserdisc flood new [Re: btribble]
#376111 - 05/12/18 11:41 PM


If you sent them to mamedev then they are still around waiting for more dumping as far as I know.



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376112 - 05/13/18 01:03 AM


> As far as I know those details aren't figured out yet.

The new lossless AV1 would be nice.



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376113 - 05/13/18 02:37 AM


> Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which
> we're getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

Finally!



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We are glad to help you but simply posting that something does not work is not going to lead to you getting help. The more information you can supply defining your problem, the less likely it will be that you will get smart-alec replies.

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I'm excited like a fridge new [Re: Smitdogg]
#376114 - 05/13/18 02:47 AM


> Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which
> we're getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

Sounds good to me



JustNiz
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Re: DU: The great laserdisc flood new [Re: Shoegazr]
#376115 - 05/13/18 03:10 AM


> The new lossless AV1 would be nice.

Digitising LaserDiscs is unavoidably lossy as they are analog.



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376116 - 05/13/18 03:15 AM


YES! Those things aren't going to last forever, it's great that there's finally going to be high quality backups of them now!

Does anyone know if there's a surviving Atomic Castle disc still in existence? I heard the game sucked but I've always been curious about it and given there was like only one or two made it would be a good one to save if it still survives somewhere.



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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376117 - 05/13/18 03:43 AM Attachment: DomDup_comparison.jpg 131 KB (0 downloads)


>
> Digitising LaserDiscs is unavoidably lossy as they are analog.

As far as I understand, what this hardware is doing is EXACTLY what everyone who has criticized LD captures said was required.
It records the actual signal from the laser of the LD player then that signal is used by an emulated LD player to either be played or converted to .avi's et al.

Image showing a comparison of the same frame captured as RGB and as RF

[ATTACHED IMAGE - CLICK FOR FULL SIZE]

Attachment



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JustNiz
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Re: DU: The great laserdisc flood new [Re: *=/STARRIDER\=*]
#376118 - 05/13/18 04:36 AM


Even so, that would still be lossy.
There is no way to go from analog to digital without quantisation loss.
LaserDisc is analog. AVI (or whatever) is digital.



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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376119 - 05/13/18 04:55 AM


Obviously you have no idea who you are talking to!
I know exactly what you are saying but the signal on the LD is an Analog signal so there is no way to get a digital copy!
The ONLY (and preferable) method is to capture that analog information directly from the format it was saved to (LD) and preserve it directly in digital format without any further analog processing!
As far as I understand, that is the goal of this project and there will always be naysayers like yourself but I'm sorry you cannot get a digital copy of something that was never recorded digitally!

This is the best option available.

In theory, if enough captures of the same thing were made from several different LD's then a MASTER copy could be assumed.

By your logic NO Music or Movies recorded Analog should have ever been reproduced on CD or DVD!
I cant image a world where that were the case.

Edited by *=/STARRIDER\=* (05/13/18 05:02 AM)



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Shoegazr
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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376120 - 05/13/18 05:13 AM


> > The new lossless AV1 would be nice.
>
> Digitising LaserDiscs is unavoidably lossy as they are analog.

Besides the point. Even inherently "lossy" analog sources could be captured in a lossless manner. But okay, AV1 does lossy too.



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Re: DU: The great laserdisc flood new [Re: *=/STARRIDER\=*]
#376121 - 05/13/18 05:23 AM


> Obviously you have no idea who you are talking to!

I think your last answer gave me a clue

> there will always be naysayers like yourself

Lol. This is not just my personal opinion, its a basic law of information theory.

> The ONLY (and preferable) method is to capture that analog information directly from the format it was saved to (LD) and preserve it directly in digital format

Please do go ahead and explain how this is somehow not converting analog to digital, and how it magically avoids quantisation loss of the analog signal. I could do with a laugh.

> By your logic NO Music or Movies recorded Analog should have ever been reproduced on CD or DVD! I cant image a world where that were the case.

Wow do you really not understand the difference between "some information/quality loss" and "no information at all"? FYI movies copied from tape/film onto DVD are in fact also lossy so necessarily lower quality than the original. Not only just from quantisation loss, but also because the compression algorithm used is intentionally VERY lossy and actively throws away quite a lot of information (in fact most of it), just to make the amount of information remaining small enough to fit a whole movie on a DVD.

Edited by JustNiz (05/13/18 05:48 AM)



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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376122 - 05/13/18 05:51 AM


Exactly my point! So you dislike all movies and music on DVD and CD that were made from analog recordings?

Maybe I just assumed you are criticizing this?
What exactly is your point?
Yes it's obviously apparent to EVERYONE that this is a lossy capture.
But what is your point?
It shouldn't be used?
There's a better way?

Please educate me!



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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376123 - 05/13/18 05:55 AM


> Even so, that would still be lossy.
> There is no way to go from analog to digital without quantisation loss.
> LaserDisc is analog. AVI (or whatever) is digital.

While technically correct, that's not really a useful thing to say. Any analog signal will have some level of noise. Beyond a certain point, increasing bit depth just captures the noise in more detail - it doesn't capture any more information from the signal. Similarly, if a signal is band-limited you gain no information by increasing the sampling frequency once it's past twice the highest-frequency component of the source material.

In a LaserDisc, there are only two levels (pit/land). The noise comes in from manufacturing tolerances that cause the lengths of the pits to vary, and ageing effects on the discs as they distort from temperature changes. You only need 1-bit samples of a sufficiently high frequency that the period between samples is smaller than the manufacturing tolerances of the pressing process to get an effectively lossless capture. Increasing the sample rate would capture noise in more detail.

Separating the carriers and demodulating the audio and video is inherently lossy. Any conversion to an A/V container format, even using lossless codecs, is going to be lossy as it requires carrier separation and demodulation. The archival dumps will not be in an A/V container format.

I don't know what the exact figures you need to get an effectively lossless capture of a LaserDisc, but I trust that the guys working to archive the Domesday Project material know what they're doing.



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Re: DU: The great laserdisc flood new [Re: *=/STARRIDER\=*]
#376124 - 05/13/18 07:08 AM


> As far as I understand, what this hardware is doing is EXACTLY what everyone who has
> criticized LD captures said was required.
> It records the actual signal from the laser of the LD player

Quite right, and it brings a tear to my eye to see that a small group of people (really just Simon and Ian) have finally made the hardware that I've said for years would be necessary to capture a laserdisc to MAME standards. In a way it feels vindicating.

I can personally vouch for Simon of the Domesday crew being an awesomely capable dude, who shares the same passion as the MAME team and the DU in terms of preserving history. I've been working on a Philips VP415 driver, which is the LV-ROM player used in the Domesday system. When I pointed out to Simon that the player dumps on the Domesday Project website lacked a couple of microcontroller dumps, he actually pulled apart his own priceless VP415 player, desoldered them, and dumped them.

As it happens, the dude also lives literally a 15-minute drive from my house, so at some point I'm going to have to check out his retro computer collection. I'll bring my camera.



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Re: DU: The great laserdisc flood new [Re: MooglyGuy]
#376125 - 05/13/18 07:13 AM


This is truly fantastic news! Any thoughts on properly dumping the CED discs? I seem to recall at least one game using them. But memory could be all wrong there.



MooglyGuy
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Re: DU: The great laserdisc flood new [Re: Kitsune Sniper]
#376126 - 05/13/18 07:15 AM


> This is so cool. I can't wait to hear the specifics of how the video data on these is
> being dumped. Looking forward to reading about it in the future!

Good news, you can read about it now!

The Domesday Duplicator is hardware which was developed to capture, at the lowest possible level, the data on LV-ROM discs used in the BBC's "Domesday" project from 1986. It just so happens that LV-ROM discs are simply laserdiscs with the option to have specially-encoded data embedded in the signal, replacing audio, of one or more frames. A specially-equipped LV-ROM player - like the Philips VP415 - could read it out.

The thing is, the effective result is a device that can not just dump LV-ROM discs, but which is a general-purpose LD dumping solution that can perform captures at the accuracy level that some of us (like me) have been screaming for for years. Anyway, there's a whole website, check-ch-check it out: https://www.domesday86.com/?page_id=978



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Re: DU: The great laserdisc flood new [Re: MC68K]
#376127 - 05/13/18 07:25 AM


> This is truly fantastic news! Any thoughts on properly dumping the CED discs? I seem
> to recall at least one game using them. But memory could be all wrong there.

CED's different again - it's an actual analog signal on the disc, as opposed to the discrete value, continuous time LaserDisc setup. Also CED degrades badly with repeated playback since the stylus contacts the groove directly. There's a bit more hope for VHD since the groove is under a protective coating so the stylus doesn't make direct contact with it.



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Re: DU: The great laserdisc flood new [Re: Tornadoboy]
#376129 - 05/13/18 11:15 AM



> Does anyone know if there's a surviving Atomic Castle disc still in existence? I
> heard the game sucked but I've always been curious about it and given there was like
> only one or two made it would be a good one to save if it still survives somewhere.

AFAIK Atomic Castle was never produced/released.
A few years ago, John Mendoza was doing a research about that game (The Search for Eon) but I can't find anything about it online ?!



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376130 - 05/13/18 11:25 AM


> ...There's going to be a tidal wave of laserdisc dumps.

...and all of a sudden prices of the mass storage devices goes through the roof !!!



italiandoh
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Re: DU: The great laserdisc flood new [Re: CTOJAH]
#376131 - 05/13/18 12:46 PM


> > Does anyone know if there's a surviving Atomic Castle disc still in existence? I
> > heard the game sucked but I've always been curious about it and given there was
> like
> > only one or two made it would be a good one to save if it still survives somewhere.
>
>
> AFAIK Atomic Castle was never produced/released.
> A few years ago, John Mendoza was doing a research about that game (The Search for
> Eon) but I can't find anything about it online ?!

Info on DLP



italiandoh
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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376132 - 05/13/18 12:57 PM


> Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which
> we're getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

I would contribute by dumping my discs if I can get one of these and instructions on how to properly use it. I have several discs that no one ever bothered to dump. I've been looking for an easy solution for years.

Matteo



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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376133 - 05/13/18 02:33 PM


Wow... Just... WOW!

This is some of the best MAME-related news I've heard in years. Kudos to everyone involved for making it happen!



f205v
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Re: DU: The great laserdisc flood new [Re: italiandoh]
#376136 - 05/13/18 05:01 PM


Matteo, I'll have one, and we can share using it, no problem mate!



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Re: DU: The great laserdisc flood new [Re: f205v]
#376138 - 05/13/18 05:46 PM


Just so everyone is clear, this will not work with just any LD player it requires a Pioneer LD-V4300D (which may be next to impossible to find) or similar that provide RF output but will require adjustment.

Edited by *=/STARRIDER\=* (05/15/18 05:30 AM)



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JustNiz
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Re: DU: The great laserdisc flood new [Re: *=/STARRIDER\=*]
#376141 - 05/13/18 08:10 PM


> Exactly my point! So you dislike all movies and music on DVD and CD that were made from analog recordings?

Please stop making incorrect ASSumptions and putting your words in my mouth. Of course I don't.

> Maybe I just assumed you are criticizing this?

Yes, you did. Actually I've never seen a reason to not digitise LDs. I've been frustated for years that MAMEDEV wouldn't accept digitising
*some* LDs apparently just because someone suddenly decided it was lossy therefore not perfect therefore not up to MAMEs standards, even
though achieving a perfect digital dump/copy of an LD is actually impossible.
The further irony being that an obvious double-standard exists because some LD games have already been emulated in MAME
for years such as Firefox, MACH3 and others. I'd much rather see something preserved/emulated ASAP as well as currently possible/viable,
then possibly improved on later, rather than just ignored and possibly lost forever because of some cluelessly applied technicality.

> What exactly is your point?
If you go back and read my original post, it was in response to someone suggesting loss-free compression would be nice.
My response was simply stating a FACT that digitising LaserDiscs is unavoidably lossy as they are analog. Then you jumped right in on the assume train.

> Yes it's obviously apparent to EVERYONE that this is a lossy capture.
Really? even you? Remember this you posted yesterday?:
> As far as I understand, what this hardware is doing is EXACTLY what everyone who has criticized LD captures said was required.
Nope, assuming you agree that the criticism (that I've never agreed with, but whatever) was that it needed to be exact (i.e. lossless) to be in MAME.
Even this approach is actually still lossy. But I welcome it because it signals that finally that whole stupid and meaningless "must be perfect" argument
is finally coming to an end, so we can now have more LD games preserved.

Also you wrote,
>In theory, if enough captures of the same thing were made from several different LD's then a MASTER copy could be assumed.
Really not. Averaging multiple reads would be a great idea as it may eliminate spurious read errors so get the dump much closer, but it is formally impossible to ever
get back to exactly what was on the MASTER, even with an infinite supply of untouched LDs and infinite number of reads.

> But what is your point?
That dumping LDs is inherently lossy, but that shouldn't stop us.
Secondly, people responding to posts need to respond to what was actually written, not the voices in their head.

> It shouldn't be used?
There you go incorrectly assuming thats what I must have meant again.

> There's a better way?
There's ALWAYS a better way possible when capturing analog. Higher resolution/faster A2D converters, higher quality analog compnents, smoothed out power etc etc.
Its the same reason why Audiophiles spend fortunes on DACs and amplifiers but no matter how far down that road you go it can never be perfect by definition.
Since you ask I'd suggest its best to use the actual player used in each disks' machine and use equipment that samples its output as accurately as possible,
and also do exactly like you said: average over several reads/disks. Using the correct player for each arcade game would mean all the artifacts that the player's cheap
electronics introduced are also captured, so the final result would more closely recreate the actual arcade experience, warts and all.
That point alone does lead to a whole philosophical debate about what MAME is actually trying to preserve/emulate though.

> Please educate me!
I tried.

Edited by JustNiz (05/13/18 08:29 PM)



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Re: DU: The great laserdisc flood new [Re: *=/STARRIDER\=*]
#376151 - 05/14/18 02:30 AM


> Just so everyone is clear, this will not work with just any LD player it requires a
> Pioneer LD-V4300D which may be next to impossible to find.

So it does not work on the Philips VP415 player it was designed to?
Is it also not possible to adjust R4 & R5 for the Sony LDP-1500P RF signal gain?
How do you know?



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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376152 - 05/14/18 02:41 AM


Well, I'm done talking to you, but I just want to inform you that there is no double standard!
The reason some LD games are in MAME while most are not is simply because the games that are in MAME were captured in a way that included the Metadata encoded in the vertical blanking interval.

There were only one or two setups to do these captures and it basically ended before it really got started.

Keep replying to me if you want but I'm done.



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Re: DU: The great laserdisc flood new [Re: RdW]
#376153 - 05/14/18 02:52 AM


Well I don't know that it can't be made to work with a different LD Player but that is the player it was developed to work with.

https://www.domesday86.com/?page_id=1176



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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376154 - 05/14/18 03:31 AM


> If you go back and read my original post, it was in response to someone suggesting
> loss-free compression would be nice.

> My response was simply stating a FACT that digitising LaserDiscs is unavoidably lossy
> as they are analog.

Generational loss is something we can't control, compression loss is something we can control.

Generational loss has a minor impact on the video signal, compression loss has a major impact on the video signal.

Which of the two do you think we should worry the most about?

We also can't control laser rot, but we can try to preserve as much of the signal as possible & keep looking for discs in better shape and try to remaster it.

> Nope, assuming you agree that the criticism (that I've never agreed with, but
> whatever) was that it needed to be exact (i.e. lossless) to be in MAME.
> Even this approach is actually still lossy.

The previous dumps for MAME were done using loss less compression. The problem was they were made with video capture cards, which don't capture all the data on the disc. This has made it impossible to emulate some of the games.

Do you understand why this is important now?



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definitely material for MAME FAQ section imo new [Re: John Doe]
#376155 - 05/14/18 04:45 AM




>> My response was simply stating a FACT that digitising LaserDiscs is unavoidably lossy
>> as they are analog.

>Generational loss is something we can't control, compression loss is something we can
>control.

>Generational loss has a minor impact on the video signal, compression loss has a major
>impact on the video signal.

>Which of the two do you think we should worry the most about?

>We also can't control laser rot, but we can try to preserve as much of the signal as
>possible & keep looking for discs in better shape and try to remaster it.

>> Nope, assuming you agree that the criticism (that I've never agreed with, but
>> whatever) was that it needed to be exact (i.e. lossless) to be in MAME.
>> Even this approach is actually still lossy.

>The previous dumps for MAME were done using loss less compression. The problem was they
>were made with video capture cards, which don't capture all the data on the disc. This
>has made it impossible to emulate some of the games.


from Aaron Giles' site

-
In 2008 I extended the CHD format to support laserdiscs, in order to enable MAME to support the handful of laserdisc-based games that came out in the 1980s. During this process I investigated how laserdiscs worked and developed tools to extract the frame metadata that was encoded in the vertical blanking interval.
-



It's too bad Aaron's older site isn't around (maybe retained on Archives?) that explained the procedure for capturing data from discs from his wip blog from 2009.

Someone that handles the MAME FAQ section could add material explaining how the laser disc data capture was done in 2009 and what is being done these days and why the current supported laser discs in MAME need to be redone again.

It should (hopefully?) resolve some of the confusion that new users might be wanting to ask.....in case any return later wanting to see what the fuss is about with possibly more laserdisc game support possibly taking place within coming months.



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Mad Dog McCree! new [Re: Smitdogg]
#376156 - 05/14/18 04:52 AM



That is the only LD game that matters. Let's make this happen.

Who cares about Star Rider?....kidding.


>Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which we're
>getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

Props and kudos for this achievement in the process of taking shape and preserving the various LD games whatever means possible. Looking forward to seeing better images of CubeQuest down the road.



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Re: Mad Dog McCree! new [Re: gregf]
#376157 - 05/14/18 04:56 AM


Fuck You Greg! Kidding...;)

Matt O has pretty much emulated and documented everything about SR!
I live for the day it's playable in MAME!



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Re: Mad Dog McCree! new [Re: *=/STARRIDER\=*]
#376158 - 05/14/18 05:02 AM



>Fuck You Greg! Kidding...;)


Heh. I knew that was going to work. :-)

Anyway the LD community fanbase can eventually rejoice.



o/t

Maybe I'll say something bad on Loonybin forum, about NE Patriots and Boston Celtics going to lose to Cavs to see if that gets Fazeo to return.



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Re: Quick link to Aaron's Laserdisc explanation... new [Re: gregf]
#376161 - 05/14/18 05:28 AM


For those who care & are also a little lazy-

From Aaron's old site: aarongiles.com

About Laserdiscs: Parts III, II, & I:

https://web.archive.org/web/20090227052012/http://www.aarongiles.com:80/



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Re: Mad Dog McCree! new [Re: *=/STARRIDER\=*]
#376162 - 05/14/18 06:07 AM


Hmmm not sure what would make me think you would want to see *=/Star Rider=* emulated.

Hmmmmmm

Just kidding. It was one I played back in the day. I can't wait to see it emulated one day (hopefully soon).

IIRC this game would be difficult to emulate (compared to others). Didn't it do some crazy panning and zooming or something like that? Reversing the video maybe?

Would the frame information be encoded in the CHD as it is now with say CQ? Would it go a frame file route? I'm probably not wording it right as I don't really understand it.

Great news anyway.



Antny
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Re: Mad Dog McCree! new [Re: gregf]
#376163 - 05/14/18 06:11 AM


> Anyway the LD community fanbase can eventually rejoice.

You know I'm happy. If we can only capture that damn WG video reel

Now if only that courriersud would return My life would be complete.

Slowed down this week. PM you soon.

Edited by Antny (05/14/18 06:11 AM)



*=/STARRIDER\=*
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Re: DU: The great laserdisc flood new [Re: RdW]
#376164 - 05/14/18 06:26 AM


OK I was wrong! other players can be used that provide RF output but require adjustment as you said!



btribble
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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376165 - 05/14/18 06:40 AM


Went and looked it up, they were originally sent to Greg S back in 2006, and he got busy and apparently forwarded them along to Aaron sometime the next year. So hopefully yeah they can still be used!



Kitsune Sniper
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Re: DU: The great laserdisc flood new [Re: MooglyGuy]
#376166 - 05/14/18 07:38 AM


> > This is so cool. I can't wait to hear the specifics of how the video data on these
> is
> > being dumped. Looking forward to reading about it in the future!
>
> Good news, you can read about it now!
>
> The Domesday Duplicator is hardware which was developed to capture, at the lowest
> possible level, the data on LV-ROM discs used in the BBC's "Domesday" project from
> 1986. It just so happens that LV-ROM discs are simply laserdiscs with the option to
> have specially-encoded data embedded in the signal, replacing audio, of one or more
> frames. A specially-equipped LV-ROM player - like the Philips VP415 - could read it
> out.
>
> The thing is, the effective result is a device that can not just dump LV-ROM discs,
> but which is a general-purpose LD dumping solution that can perform captures at the
> accuracy level that some of us (like me) have been screaming for for years. Anyway,
> there's a whole website, check-ch-check it out:
> https://www.domesday86.com/?page_id=978

Thanks for the link. It's amazing how good of a signal this device can get from RF. Hope this system is used by other preservation projects in the future. LDs are fragile as it is, and rot is becoming more and more common...



taz-nz
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Re: DU: The great laserdisc flood new [Re: CTOJAH]
#376167 - 05/14/18 11:32 AM


Yeah with 220GB images, there is going to be a sudden rush on 12tb drives.


or the solution to all your mame storage needs: This



StilettoAdministrator
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Re: DU: The great laserdisc flood new [Re: CTOJAH]
#376169 - 05/14/18 12:28 PM


> > Does anyone know if there's a surviving Atomic Castle disc still in existence? I
> > heard the game sucked but I've always been curious about it and given there was
> like
> > only one or two made it would be a good one to save if it still survives somewhere.
>
>
> AFAIK Atomic Castle was never produced/released.
> A few years ago, John Mendoza was doing a research about that game (The Search for
> Eon) but I can't find anything about it online ?!

http://atomiccastle.com/

- Stiletto



taz-nz
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Re: DU: The great laserdisc flood new [Re: Vas Crabb]
#376170 - 05/14/18 12:39 PM


I still think that you could reduce some analogue noise by building a modified laserdisc player, that has a high mass turntable, like those you find on audiophile record players.


The heavy turntable would act as a flywheel smoothing out any cogging from the drive motor. Thus removing any changes in linear speed, and the effective noise this would induce in the playback. This would make the playback of the disc far more consistent from one capture to the next.



taz-nz
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Re: DU: The great laserdisc flood new [Re: John Doe]
#376171 - 05/14/18 01:14 PM



> We also can't control laser rot, but we can try to preserve as much of the signal as
> possible & keep looking for discs in better shape and try to remaster it.

If we have high quality consistant captures, it should be possible to compare captures from multiple discs of a game, and create an image without laser dropouts, by substuting the missing sections.

Not a simple task, but something that should be possibe in the future as long as we have enough high quality captures of different discs.



Simon Inns
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Re: DU: The great laserdisc flood new [Re: CiroConsentino]
#376173 - 05/14/18 04:18 PM


Hi, Simon here (from Domesday86.com) - thanks all for the kind words about the project! I'm super-happy to see more people interested and getting involved; it's been around 2 years since Ian and I started outlining plans to recreate the Domesday system; I don't think when we started we had any idea that the project would grow in such a universal manner. The Duplicator is the third sub-project (the others were SmallyMouse2 and BeebSCSI, both of which are now in the 100s of users) and I'm dedicated to keeping it open-source/hardware all the way.

The Domesday Duplicator is pretty much bleeding-edge when it comes to LaserDisc duplication - the situation is a little 'chicken and egg' with the issues of both capture and decode needing to evolve together (and be tested together). The design had two primary aims - capture the disc (everything on the disc!) at 8 times the Nyquist (of both PAL (35MSPS) and NTSC (28MSPS)) and do it cheaply (there are professional ADC capture systems already, but they are literally 100 times more expensive and closed-licensed).

For those interested in the decoding process, I've written a high-level guide to what the LaserDisc player does (it's not 'nose-bleed' technical!):

LaserDisc Decoding Guide

There is also a new Facebook group for support if you are building one of the boards:

Domesday86 on Facebook



CTOJAH
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Re: DU: The great laserdisc flood new [Re: Stiletto]
#376174 - 05/14/18 04:23 PM


> > > Does anyone know if there's a surviving Atomic Castle disc still in existence? I
> > > heard the game sucked but I've always been curious about it and given there was
> > like
> > > only one or two made it would be a good one to save if it still survives
> somewhere.
> >
> >
> > AFAIK Atomic Castle was never produced/released.
> > A few years ago, John Mendoza was doing a research about that game (The Search for
> > Eon) but I can't find anything about it online ?!
>
> http://atomiccastle.com/
>
> - Stiletto

Yeah, that's the site, but unfortunately links are dead !
( Try clicking on http://atomiccastle.com/thesearch.html)



Kitsune Sniper
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Re: DU: The great laserdisc flood new [Re: taz-nz]
#376176 - 05/14/18 06:15 PM


> Yeah with 220GB images, there is going to be a sudden rush on 12tb drives.
>
>
> or the solution to all your mame storage needs: This

Is that what an average LD image is going to be? It seems a bit... small?



Roman
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Re: DU: The great laserdisc flood new [Re: Kitsune Sniper]
#376177 - 05/14/18 06:21 PM


question is what size you're talking about...the raw one? The compressed one? What data is captured, how it will be encoded...in which container it will be put to...what the compression of the container will be...



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Re: DU: The great laserdisc flood new [Re: Roman]
#376178 - 05/14/18 07:39 PM


> question is what size you're talking about...the raw one? The compressed one? What
> data is captured, how it will be encoded...in which container it will be put
> to...what the compression of the container will be...

If that's the size of a raw one, it still seems too small to me. I figure compression will not lower the size that much because of the uh... analog noise? That example photo seemed to have a bit of noise, even in the cleaned up image.

I don't know how the signal is being stored digitally, so I'm probably wrong.



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Re: DU: The great laserdisc flood new [Re: CTOJAH]
#376179 - 05/14/18 07:54 PM


> > > > Does anyone know if there's a surviving Atomic Castle disc still in existence?
> I
> > > > heard the game sucked but I've always been curious about it and given there was
> > > like
> > > > only one or two made it would be a good one to save if it still survives
> > somewhere.
> > >
> > >
> > > AFAIK Atomic Castle was never produced/released.
> > > A few years ago, John Mendoza was doing a research about that game (The Search
> for
> > > Eon) but I can't find anything about it online ?!
> >
> > http://atomiccastle.com/
> >
> > - Stiletto
>
> Yeah, that's the site, but unfortunately links are dead !
> ( Try clicking on http://atomiccastle.com/thesearch.html)

That's the only Error 404 on the site, actually. Probably intentional. I emailed the site admin four years ago, I can ping him to verify, but that page is probably intentionally offline due to it not yet being ready to publish.

- Stiletto



agard
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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376180 - 05/14/18 07:57 PM


What does this actually mean ? Apart from all the moaning about what format is gonna be used during this process does it mean we'll have working copies of Space Ace & Dragon's Lair in MAME in the not so distant future ?

Make an exact copy of the laser disc then people can choose there own format but more than likely the format they choose won't work in MAME.

It's been a long time coming so thanks to all involved in the project.

THANKS



Simon Inns
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Re: DU: The great laserdisc flood new [Re: Kitsune Sniper]
#376181 - 05/14/18 07:59 PM


The duplicator's ADC is 10-bit unsigned; the FPGA converts this to scaled 16-bit signed data (as 16-bit is the only thing the USB3 can pass - you have to transfer 16-bit anyway). Since there is no processing of the sample by the Linux app, that is what is stored on the hard drive.

So you have NTSC capture at 28.63 MSPS @ 16-bit and PAL capture at 35.47 MSPS. The size of the sample depends on the length of the disc, so it's approximately:

1 second NTSC = (2 bytes * 28,630,000 samples) = 54.6 MBytes
1 second PAL = (2 bytes * 35,470,000 samples) = 70.9 MBytes

So if you sample 60 minutes of an NTSC disc (one side of a CLV) you end up with about 200 Gbytes of data or 250 Gbytes for PAL.

Since (as someone pointed out earlier) the disc is pits and troughs the most important thing you get from ADC resolution is actually sensitivity across a wider peak-to-peak RF range (as the signal is weak at the beginning of a disc and strong at the end). So 10-bits was the compromise between need and cost (ADCs get a *lot* more expensive above 10-bits).



gregf
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Re: DU: The great laserdisc flood new [Re: agard]
#376182 - 05/14/18 08:56 PM



>What does this actually mean? Make an exact copy of the laser disc then people can choose
>their own format....

Actual laser disc owners can preserve their own laser discs as best possible. Useful for cab owners that still have working cabs with original laser disc players....that is if even possible in this day and age since many of the laser players are probably no longer working these days.

https://www.domesday86.com/ home page

https://www.domesday86.com/?page_id=978 Domesday Duplicator product



>...format they choose won't work in MAME.

A decision that will be made by MAMEdevs....in case there are laser disc owners willing to contribute to MAME later in preserving laser disc games. Standards (hopefully) will be in place. Laser disc owners can choose whatever they want for their own specific needs in case they still use a cab to run laser disc games.


>...mean we'll have working copies of Space Ace & Dragon's Lair in MAME in the not so
>distant future?


I doubt it. I can see Digital Leisure's corporate lawyers go ballistic and send a cease letter to MAME. Laser disc owners can still do their thing (archiving their discs), but those specific laser disc games probably won't be supported in MAME.



*crossing fingers American Leisure products aren't in same situation*



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Re: DU: The great laserdisc flood new [Re: Simon Inns]
#376183 - 05/14/18 09:41 PM



Thanks for the visits and posting some explanations as well.

--
The duplicator's ADC is 10-bit unsigned; the FPGA converts this to scaled 16-bit signed data (as 16-bit is the only thing the USB3 can pass - you have to transfer 16-bit anyway). Since there is no processing of the sample by the Linux app, that is what is stored on the hard drive.

So you have NTSC capture at 28.63 MSPS @ 16-bit and PAL capture at 35.47 MSPS. The size of the sample depends on the length of the disc, so it's approximately:

1 second NTSC = (2 bytes * 28,630,000 samples) = 54.6 MBytes
1 second PAL = (2 bytes * 35,470,000 samples) = 70.9 MBytes

So if you sample 60 minutes of an NTSC disc (one side of a CLV) you end up with about 200 Gbytes of data or 250 Gbytes for PAL.

Since (as someone pointed out earlier) the disc is pits and troughs the most important thing you get from ADC resolution is actually sensitivity across a wider peak-to-peak RF range (as the signal is weak at the beginning of a disc and strong at the end). So 10-bits was the compromise between need and cost (ADCs get a *lot* more expensive above 10-bits).

--


Your post here along with someone else's post would be ideal MAME FAQ material imo since it explains expected sizes of future CHD data of various laser discs. And also shows why Aaron Giles' method used in 2008 was a temporary stopgap method, but useful for showing laser disc data can also be stored in CHD at that time. Aaron's work at the time showed it was possible then.

Hopefully something regarding laser discs will be added or updated to MAME FAQ section later.

--
> Nope, assuming you agree that the criticism (that I've never agreed with, but
> whatever) was that it needed to be exact (i.e. lossless) to be in MAME.
> Even this approach is actually still lossy.

The previous dumps for MAME were done using loss less compression. The problem was they were made with video capture cards, which don't capture all the data on the disc. This has made it impossible to emulate some of the games.


https://web.archive.org/web/20090227052012/http://www.aarongiles.com:80/


About Laserdiscs, part 3 (errata)
About Laserdiscs, part 3
About Laserdiscs, part 2
About Laserdiscs, part 1
--




I can envision laser disc owners will be grateful with your product coming to the rescue in preserving various video game laser discs. Gotta make certain that American Leisure's products such as Mad Dog McCree is preserved. :-) If that game is allowed (MAMEdev's decision) to be supported in MAME later, I'll be a happy camper.



o/t

I didn't play laser disc games in arcades myself since most of my years in arcades were prior to laser disc games appearing in arcades (1968 to 1987).

Mine was film reel based projection screen games from 1970s (used slides or film reels) whether it be Nintendo products, US Billiards etc.



italiandoh
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Re: DU: The great laserdisc flood new [Re: f205v]
#376184 - 05/14/18 10:03 PM


> Matteo, I'll have one, and we can share using it, no problem mate!

Great, thanks. I can buy one too if it's available.

Matteo



italiandoh
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Re: DU: The great laserdisc flood new [Re: *=/STARRIDER\=*]
#376185 - 05/14/18 10:04 PM


> Just so everyone is clear, this will not work with just any LD player it requires a
> Pioneer LD-V4300D which may be next to impossible to find.

I have one.

Matteo



agard
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Re: DU: The great laserdisc flood new [Re: gregf]
#376187 - 05/15/18 12:15 AM


It's just weird that all over the web is Daphne emu with all roms & the dvds plus all the other American laser disc games fully working & Daphne emu is free & so is MAME so why Digital Leisure would go after MAME I can't see it there both emulators but MAME has it's identity of preserving games but if MAME does successfully emulate Digital Leisure stuff but not include it in official MAME I can see someone doing there own build to include them but you never know what can happen.



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Re: DU: The great laserdisc flood new [Re: gregf]
#376188 - 05/15/18 12:29 AM


> *crossing fingers American Leisure products aren't in same situation*


Quote:


In 2000, the development and publishing rights to all of the games that were produced by American Laser Games were purchased by Digital Leisure, Inc from Her Interactive.




https://en.wikipedia.org/wiki/American_Laser_Games

- Stiletto



gregf
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Re: DU: The great laserdisc flood new [Re: agard]
#376189 - 05/15/18 12:30 AM



>It's just weird that all over the web is Daphne emu with all roms & the dvds plus all the
>other American laser disc games fully working & Daphne emu is free & so is MAME so why
>Digital Leisure would go after MAME I can't see it there both emulators but MAME has it's
>identity of preserving games but if MAME does successfully emulate Digital Leisure stuff
>but not include it in official MAME I can see someone doing there own build to include them
>but you never know what can happen.

I don't play laser disc stuff myself, but iirc from reading on forums a long time Daphne still relied on Digital Leisure discs to play Dragon's Lair? It was some agreement/arrangement between Daphne developers and Digital Leisure that allowed Daphne to emulate some of the popular cash generating laser disc games (Dragons Lair series and Space Ace series). At this point, I can't see Digital Leisure's corporate law firm jumping in compared to say 2000 AD.....but hard to say. Younger generations could care less imo.

MAMEDev members contributors can give more exact answers than what I posted, but that is what I recall being posted many years ago.

If Digital Leisure was very aggressive 15 to 20 years earlier, I still say play it safe and have other laser disc games emulated in MAME first. Start with existing supported laser disc games CubeQuest and go from there.



gregf
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Re: DU: The great laserdisc flood new [Re: Stiletto]
#376190 - 05/15/18 12:35 AM



> *crossing fingers American Leisure products aren't in same situation*


-
In 2000, the development and publishing rights to all of the games that were produced by American Laser Games were purchased by Digital Leisure, Inc from Her Interactive.
-

https://en.wikipedia.org/wiki/American_Laser_Games


Aw....frick. I hope they don't get jumpy if laser disc stuff starts taking place again in MAME. If the company and corporate lawyers see a future cash generating product somehow magically happening once again...they must be wearing rose-colored blinders.

"Yes......we can make money with penny stocks, derivative junk bonds, and very old games that none of the younger generations have any interest of." ;-)



JustNiz
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Re: DU: The great laserdisc flood new [Re: gregf]
#376192 - 05/15/18 02:38 AM


> The duplicator's ADC is 10-bit unsigned; the FPGA converts this to scaled 16-bit
> signed data ...
> So you have NTSC capture at 28.63 MSPS @ 16-bit

Sorry to be pedantic but that claim is a bit of a stretch. you really only still have it at 10 bit resolution, just expressed as a 16 bit value.



JustNiz
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Re: DU: The great laserdisc flood new [Re: John Doe]
#376193 - 05/15/18 02:46 AM


> they were made with video capture cards, which don't capture all the data on the
> disc. This has made it impossible to emulate some of the games.

Not really impossible. Even with just the video, frame files would have been one option. Far from ideal but better than nothing.



JustNiz
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Re: DU: The great laserdisc flood new [Re: gregf]
#376195 - 05/15/18 03:20 AM


> I don't play laser disc stuff myself, but iirc from reading on forums a long time
> Daphne still relied on Digital Leisure discs to play Dragon's Lair? It was some
> agreement/arrangement between Daphne developers and Digital Leisure that allowed
> Daphne to emulate some of the popular cash generating laser disc games (Dragons Lair
> series and Space Ace series).

There was a point prior to that when Daphne emulated Dragons Lair 1&2, Space Ace and Thayers Quest using just regular AVI (or was it MP4?) dumps of the LDs (using frame files). When Digital Leisure came out with the remastered DVDs, Daphne changed to only supporting their versions through a purchased key/download.



Kitsune Sniper
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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376200 - 05/15/18 04:23 AM


> > The duplicator's ADC is 10-bit unsigned; the FPGA converts this to scaled 16-bit
> > signed data ...
> > So you have NTSC capture at 28.63 MSPS @ 16-bit
>
> Sorry to be pedantic but that claim is a bit of a stretch. you really only still have
> it at 10 bit resolution, just expressed as a 16 bit value.

He was talking about how it was being stored. He very clearly says it's 10 bit data in a 16 bit format in the previous paragraph.

Sheesh.



*=/STARRIDER\=*
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Re: DU: The great laserdisc flood new [Re: italiandoh]
#376201 - 05/15/18 05:09 AM


> > Just so everyone is clear, this will not work with just any LD player it requires a
> > Pioneer LD-V4300D which may be next to impossible to find.
>
> I have one.
>
> Matteo

That is MUSIC to my ears as I know who you are and have an Idea of what you have, but more importantly I know how you feel about the preservation of LD games!



Kitsune Sniper
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Re: DU: The great laserdisc flood new [Re: Smitdogg]
#376204 - 05/15/18 06:33 AM


> Brizzo and domesday86.com teamed up on some new laserdisc dumping hardware of which
> we're getting 10 copies. There's going to be a tidal wave of laserdisc dumps.

I let a person who is doing Laserdisc rips of old anime for preservation and restoration purposes know about the project, and he told me to relay this to you all:


Quote:


Oh. To those bros in that page you linked, those laserdisc games are 1 sided. The other side is a metal blank to act as a flywheel for durability. I would ONLY use an industrial player, not even the behemoth X0, since indy players are built to handle that kinda thing.





Source: https://twitter.com/nateblasted32/status/996244914387214337

Not sure how accurate this is since I've got very limited info on these things, but do arcade LDs have metal sides? Seems odd.



Simon Inns
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Re: DU: The great laserdisc flood new [Re: Kitsune Sniper]
#376205 - 05/15/18 07:10 AM



Quote:


I would ONLY use an industrial player




The Pioneer LD-V4300D was chosen as the reference player for a number of reasons:


  • The testing cycle for the board is quite involved and targeting many players isn't practical (or affordable)
  • The player is industrial and single-sided which means the mechanism is strong and the head-tracking as solid as possible
  • The player is NTSC and PAL compatible and supports digital and analogue audio
  • The player is RS232 controllable (allowing the 'player integrated capture' functionality)
  • The player has a good, clear service manual which is widely available
  • The player is fairly modern and seems to be relatively easy to source (I had to buy 3 just for this project)


There is no reason why you cannot use other players - but there is no standard for the RF-tap; so you will be on your own to verify the RF stage and adjust for the player (please publish the results if you do this though!).

On the resolution - yes it's 'only' 10-bits but that is being used to record the RF (it is not video and the two should not be confused). The RF signal is generated by the laser shifting between two distances (pit or no pit) - so the resolution provides sensitivity when detecting the current state - you could go to 10 million bits resolution and not really gain anything more except expense).

It's the sampling speed that provides most of the actual timing recovery which is why 8 times the Nyquist is way more important (and the board is capable of 40 million samples per second).

Still, the project is completely open - so if you want to modify the design and improve it, please go right ahead! I am. by no means, a world-leader in RF design. By making it open my hope is that others will join in and make it better



Olivier Galibert
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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376206 - 05/15/18 07:21 AM


So fucking what? It's still 12dB better than the digital NTSC 8bits standard, and iirc, but I'd have to check, twice the frequency. So it's going to be damn good, and in fact better quality than what's encoded on the damn LD, so for all intents and purposes lossless[1].

OG.

[1] In technical terms, "under the noise floor"



Vas Crabb
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Re: DU: The great laserdisc flood new [Re: JustNiz]
#376207 - 05/15/18 08:04 AM


> > The duplicator's ADC is 10-bit unsigned; the FPGA converts this to scaled 16-bit
> > signed data ...
> > So you have NTSC capture at 28.63 MSPS @ 16-bit
>
> Sorry to be pedantic but that claim is a bit of a stretch. you really only still have
> it at 10 bit resolution, just expressed as a 16 bit value.

And it's being used to capture a signal with 1-bit useful depth. This is the RF signal off the disc that's being captured, not composite video. The captured bit depth just needs to be enough to deal with the gain/filtering effects in the laser front-end in the player.



taz-nz
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Re: DU: The great laserdisc flood new [Re: Simon Inns]
#376208 - 05/15/18 12:40 PM


Thanks for the link, the bit about the Time-based correction was really interesting, I knew there had to distortion in playback due to motor cogging, I didn't realise they had an electronic correction system in place for it.

It makes sense they did, they couldn't really go the brute force route like early digital photocopiers, which had 20-30kgs of flywheel on the image drum to prevent striping.



JonasP
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Re: DU: The great laserdisc flood new [Re: Simon Inns]
#376209 - 05/15/18 02:01 PM


Isn't it inefficient to store the samples as 16bit? If storing the 10bit samples as a bitstream you could store 8 samples in 10bytes instead of 16...



MooglyGuy
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Re: DU: The great laserdisc flood new [Re: JonasP]
#376210 - 05/15/18 04:20 PM


> Isn't it inefficient to store the samples as 16bit? If storing the 10bit samples as a
> bitstream you could store 8 samples in 10bytes instead of 16...

It's inefficient to store on your hard drive as such. For transmission from the Domesday Duplicator board to your PC, however, absolutely not. Consider that the FPGA would need to construct that bistream from incoming parallel data, for which there might not be enough free logic elements. All in all, keeping the dumper-side pre-processing as minimal as possible is arguably better.

It's questions like these where I wouldn't really blame Simon if he just packed it in and didn't want to deal with the MAME community. A bunch of people acting like the MAME team, the DU, and the Domesday Duplicator project are simultaneously smart enough to accomplish all these various things, yet too dumb to account for something as simple as that. It really gives a lousy impression.



Simon Inns
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Re: DU: The great laserdisc flood new [Re: MooglyGuy]
#376212 - 05/15/18 04:43 PM



Quote:


It's inefficient to store on your hard drive as such




This is quite correct, however saving a bit of hard drive space at the cost of extra complexity isn't a trade off you make until everything is properly proven. This isn't a 'finished product', it's not even a 'product' - I haven't sold anything

It's an open-hardware/open-software design purely for backing up Domesday LaserDiscs. It just happens that there is a lot of scope for using it across all forms of LaserDisc preservation. As an open project it can be easily adopted, expanded and enhanced - for the benefit of anyone who sees a need for it.

If you'd like to make a suggestion for improvement, head over to the github repo and open an issue; I can't promise I will personally implement every suggestion, but at least there will be a central record for anyone who fancies a fork and pull-request cycle.



swm3rd
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Re: DU: The great laserdisc flood new [Re: Simon Inns]
#376235 - 05/16/18 09:03 PM


No mention of Galaxian3?



R. Belmont
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Re: DU: The great laserdisc flood new [Re: swm3rd]
#376236 - 05/16/18 10:39 PM


> No mention of Galaxian3?

It is far, far too early to complain about specific titles. Your post is roughly like showing up circa 1935 when electronic television was first practical and demanding Game of Thrones.

There are a *lot* of moving parts before any of these rips actually do anything in MAME. I wouldn't expect an actual flood of playable error-free LD games for 12-18 months. The actual Domesday discs oughta be running before then, though, and those promise to be super interesting.



R. Belmont
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Re: DU: The great laserdisc flood new [Re: CiroConsentino]
#376237 - 05/16/18 10:44 PM


> Cool. What video format can be expect ? MPEG-2, AVI, MPEG-4, AVC, DivX, Xvid...

None of those.

In more detail: lossy, inflexible, lossy, lossy, lossy, lossy.



Haze
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Re: DU: The great laserdisc flood new [Re: R. Belmont]
#376238 - 05/16/18 11:00 PM


> > Cool. What video format can be expect ? MPEG-2, AVI, MPEG-4, AVC, DivX, Xvid...
>
> None of those.
>
> In more detail: lossy, inflexible, lossy, lossy, lossy, lossy.

not to mention AVI is a container, not a format.

but yeah, dumb question

it will be some lossless format, like the current one, and probably, if it's going to be used by MAME, in a CHD container, like the current one as that provides streaming and checksums.

it might not compress amazingly well, but the goal is to save this data for future generations at the best possibly quality it can be captured at today without throwing away anything that is captured (which means if captures are done from different discs in the future no additional artefacts have been introduced that could get in the way of comparisons)



Olivier Galibert
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Re: DU: The great laserdisc flood new [Re: R. Belmont]
#376247 - 05/17/18 11:43 AM


> There are a *lot* of moving parts before any of these rips actually do anything in
> MAME. I wouldn't expect an actual flood of playable error-free LD games for 12-18
> months. The actual Domesday discs oughta be running before then, though, and those
> promise to be super interesting.

Also, I wonder if anybody bothered to compute 60mn * 28.63MSamp/s * 2 bytes. Impunity, etc :-)

OG.



DoomSooth
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Re: DU: The great laserdisc flood new [Re: Olivier Galibert]
#376249 - 05/17/18 01:01 PM


GregF did, goofy. Scroll up to #376183. :P



Roberto Fresca
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Re: DU: The great laserdisc flood new [Re: Olivier Galibert]
#376255 - 05/17/18 08:46 PM



> Also, I wonder if anybody bothered to compute 60mn * 28.63MSamp/s * 2 bytes.
> Impunity, etc :-)

Still recall when users claimed to zip the sets to gain disk space...

Robbie.



Kitsune Sniper
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Re: DU: The great laserdisc flood new [Re: Olivier Galibert]
#376258 - 05/17/18 09:33 PM


> > There are a *lot* of moving parts before any of these rips actually do anything in
> > MAME. I wouldn't expect an actual flood of playable error-free LD games for 12-18
> > months. The actual Domesday discs oughta be running before then, though, and those
> > promise to be super interesting.
>
> Also, I wonder if anybody bothered to compute 60mn * 28.63MSamp/s * 2 bytes.
> Impunity, etc :-)
>
> OG.

Here.


Quote:


So you have NTSC capture at 28.63 MSPS @ 16-bit and PAL capture at 35.47 MSPS. The size of the sample depends on the length of the disc, so it's approximately:

1 second NTSC = (2 bytes * 28,630,000 samples) = 54.6 MBytes
1 second PAL = (2 bytes * 35,470,000 samples) = 70.9 MBytes

So if you sample 60 minutes of an NTSC disc (one side of a CLV) you end up with about 200 Gbytes of data or 250 Gbytes for PAL.




That's before compression, IIRC.



gamerfan
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Re: Mad Dog McCree! new [Re: gregf]
#376263 - 05/18/18 04:31 AM


> Looking forward to seeing better images of CubeQuest down the road.

Here's what Cube Quest looks like right now in MAME



Check out these laserdisc games look like right now in MAME

Cobra Command


US Vs Them



btribble
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Re: DU: The great laserdisc flood new [Re: Kitsune Sniper]
#376264 - 05/18/18 04:42 AM


RE: the metal sides thing - I can confirm that some (not all, but especially older 80's era LD games) had a metal side that made the whole disc heavier. LDs are, after all, two sides glued together - from what I understand poor application and deterioration of the glue is one of the causes of "laser rot", though it shows up within a few years and makes the disc unplayable so I don't think it would be a worry at this point. Just wanted to mention it for no good reason.



Kitsune Sniper
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Re: DU: The great laserdisc flood new [Re: btribble]
#376270 - 05/18/18 07:44 AM


> RE: the metal sides thing - I can confirm that some (not all, but especially older
> 80's era LD games) had a metal side that made the whole disc heavier. LDs are, after
> all, two sides glued together - from what I understand poor application and
> deterioration of the glue is one of the causes of "laser rot", though it shows up
> within a few years and makes the disc unplayable so I don't think it would be a worry
> at this point. Just wanted to mention it for no good reason.

I can confirm this issue also happens on DVDs, particularly dual sided ones.

I hate dual sided DVDs. Haaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaate.



happycube
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Re: DU: The great laserdisc flood new [Re: Olivier Galibert]
#376279 - 05/18/18 05:19 PM


LD games were all CAV (30mins, 36min PAL) because CLV wasn't intended or useful for interactive/gaming use. (The LD-V8000 made CLV workable for it, but not until 1989 or so)

So LD games will 'only' take 100-110GB, and the 10-bit data compresses well because there are 6 bits which are always 0. And if it really became a concern a packed 3x10->32 bit framing could be done, it just hasn't been done yet. There are advantages for the dev phase for working in signed 16bit.

Edited by happycube (05/18/18 05:21 PM)



jonwil
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Re: DU: The great laserdisc flood new [Re: R. Belmont]
#376288 - 05/19/18 02:32 AM


What hardware do the Doomsday disks run on exactly?



MooglyGuy
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Re: DU: The great laserdisc flood new [Re: jonwil]
#376293 - 05/19/18 10:29 AM


> What hardware do the Doomsday disks run on exactly?

Domesday, not Doomsday. https://www.domesday86.com/?page_id=67


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