MegaLD Dumping Project

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tommyptr
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Video Ripping...

Post by tommyptr » Mon Jan 13, 2014 10:27 am

Space Berserker is NOT a good test disc, as this runs video fairly normaly. Most other discs have the 'dual frame' tech built into the viewable fields... even the lowly Pyramid Patrol does this durring boss battles, and in the tunnels.

This is speculation... Recording off normal ld players will not work. Recording off LD computer controlled players (a bit rare, but I do have one) will not work either, as LaserActive 'dual frame' tech is unique only to LA. The only way possible I can see is to get the PC-1 pac and program it to show only the visible fields..and record each disc twice. The emulator (if that is what your going to indeed do with it) is going to have to switch video files on the fly while its running... a MUCH more complex thing than say emulating LD arcade games.

The only exception perhaps is that modern video capture devices can seperate the fields in a one pass recording. Then you gotta get the emualtor to do this switching, again having its own problems.

This whole thing is unforunate as the LA is not the best LD player to record discs off from.

Nemesis
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Post by Nemesis » Tue Jan 14, 2014 3:46 am

Thanks LAPProject and tommyptr, I've updated the list of games based on your input. I'm going to keep the list showing both US and Japan releases right now, even if we have good reason to suspect the disks are identical in both regions. Until we dump both regions to confirm they're the same, I think the best course of action is to assume they might contain differences, even if it's only the build date. It's quite possible for example that even though games were intended to be bilingual, bugs were discovered and fixed between the Japan and US releases for example, meaning the later release could be a newer version. This happened a lot for Mega Drive cartridge releases even if the games weren't region locked.
LAPProject wrote:Also, to Nemesis and anyone concerned, I have an EXCELLENT NTSC capture box (Canopus ADVC110, hooks up over Firewire so make sure you have a FW400 or FW800 port available) that can do NTSC-J settings and encodes in crystal-clear DV codec (outputs a largely uncompressed AVI). They'd be good masters, but their file size is so big that we'd have to create compressed versions from them in order to keep download sizes managable for everyone else. (Not like we'd do something naughty like redistribute ROM files, right? :p Wink wink.
I've got the great grandfather of that device, the Canopus DVStorm, which was designed for live streaming video filtering and editing. It also encodes in DV, and I suspect shares a lot in common with that device. I'm planning to encode HuffyUV masters from these DV videos, which makes them even larger, but more portable. As you said though, there'll have to be a re-encode of some kind that's used for actual emulation, the super high quality version will be more archival and for future re-encoding than anything else.
LAPProject wrote:The only issue on my end is that my only LD player is the CLD-A100 itself, and currently I don't think it's possible for me to play the disc back like a standard movie... with a PAC in, it runs the game (of course), and with no PAC inserted, it tells me to insert the PAC. Is there a way to get the CLD-A100 to override that error message and play the video back straight? Or would you have to do it? If so, we may want to work something out regarding my capture box, if you need to use it.
What you'll need is a Mega Drive flashcart, like the Mega Everdrive or Everdrive MD. If you don't have one, you might want to pick one up, I'd suggest straight from the creator at http://shop.retrogate.com. I'll release a ROM that'll allow you to easily play back the video tracks with full control over the audio channel that's being used. You can then just capture the output with your capture card. Dumping of the digital data is more fussy, but I know enough to get the video dumping part working already, I still have some questions I need to answer about the audio track selection though. Note that in order to get the best quality video rip though, you'd need to do a hardware mod to grab the composite video signal from as close to the source as possible. I haven't done this yet, but I'll be attempting it soon, and I'll publish a guide once it's done so other people can do the same if they want to be involved in ripping video.

I actually think a CLD-A100 with a Sega PAC will be one of the best LaserDisc ripping machines once we complete this process. It's basically exactly what you want: A LaserDisc player directly controllable at a low level from a computer (or in this case, a Mega Drive). With a hardware mod to grab the raw composite signal straight from the demuxer, I also think the video quality will be as good or better than any other player.
McKie1 wrote:Once this project moves a bit further along, maybe you could pop down to Melbourne as we have (barring the Myst prototype and 3D Virtual Australia) all other titles on one format or the other.

We also have all the PAC's, goggles, etc.
Wow, that's quite a collection! Unfortunately, while my equipment could be moved, it'd probably be me that couldn't make it. I don't have any business or family commitments in Melbourne, and I doubt I'll be able to get down there any time in the near future. Still, if an opportunity arises, I'll definitely look you up. In the mean time, if you were willing to consider lending any of your games or equipment to further this project, I'd be very interested. Drop me a PM if you're willing, I'd be happy to discuss any questions or suggestions you might have about how we could make this work.
LAPProject wrote:One thing I wanna bring up is the method that many Mega LD games use to store video on the Laserdisc. It's not your typical encoding. Since the max resolution of the Mega Drive hardware is ~320x240 (320x224 to be exact) without jumping into Interlace mode (which they chose not to use for a reason beyond my understanding, probably some scaling issues when they laid it on top of the LD video), the LD does NOT display its full 525 lines (480i). Instead, it breaks down the 480i signal into two progressive scan fields at around 240p, and only displays one of them at a time. This allowed certain discs (Zapping TV Satsui being a prominent example) to have seamless scene transitions on command - instead of actually seeking through the disc, it would just swap whichever of the two 240p fields was visible at the time. How it managed the audio is something I'm not quite sure about, but Mega-LDs have two FM Audio tracks like a standard LD (the PCM area of the disc normally used to store CD-quality audio is used to store the ROM data), so perhaps they just swap the audio channel being played.

Keep in mind that NOT EVERY Mega-LD game does this, and the only real way to know all of the ones that do will be trial and error testing. With this in mind, I can imagine playing back the signal at 480i on a normal player will look and sound like an unintelligible mess.

Anybody have a proposed solution to this issue?
tommyptr wrote:Space Berserker is NOT a good test disc, as this runs video fairly normaly. Most other discs have the 'dual frame' tech built into the viewable fields... even the lowly Pyramid Patrol does this durring boss battles, and in the tunnels.

This is speculation... Recording off normal ld players will not work. Recording off LD computer controlled players (a bit rare, but I do have one) will not work either, as LaserActive 'dual frame' tech is unique only to LA. The only way possible I can see is to get the PC-1 pac and program it to show only the visible fields..and record each disc twice. The emulator (if that is what your going to indeed do with it) is going to have to switch video files on the fly while its running... a MUCH more complex thing than say emulating LD arcade games.

The only exception perhaps is that modern video capture devices can seperate the fields in a one pass recording. Then you gotta get the emualtor to do this switching, again having its own problems.

This whole thing is unforunate as the LA is not the best LD player to record discs off from.
It's not that much of a problem actually. The method the MegaLD games use isn't really special in any way, they just encode different video streams into the odd and even fields of the frame. The hardware allows the video output to be interleaved, even field only, or odd field only, and the game switches this video playback mode as required. This isn't non-standard or breaking in any way for any other player, it just might look a little odd to the viewer if they were watching both fields interleaved together, like watching a 3D movie without glasses for example.

Capturing the interlaced video stream with both the even and odd fields is actually preferred, and this is the way the video stream should be preserved. The fact the even and odd fields might contain totally separate video isn't important, as long as the capture device being used to record the video stream is able to capture de-interlaced video, or an interlaced video stream with no compression or a compression format that won't destroy the field separation. The Canopus capture devices manage this, but there are probably a lot of devices out there that won't unfortunately.

Here's some sample video generated from the process I'm planning to use for video capture at this stage:
https://mega.co.nz/#!YYd3wTJZ!UEB_PVEQx ... NVRsbYjB-c
This is a sample video from Sonic 2 on the Mega Drive, captured through my capture card. There are three files:
-"Sonic2VidSample - RawOriginal.avi": The raw video file captured using my capture card.
-"Sonic2VidSample - HuffyUVOriginal.avi": The same content as the above video, but encoded into HuffyUV. Both these files use the YV12 color space encoding.
-"Sonic2VidSample - Final.avi": Deinterlaced video stream, with padding added to the top to hold vertical blanking video content. Also HuffyUV encoded in the YV12 color space.

If you framestep the final video, you'll see the two fields in this video stream are actually quite different, with the bubble shield around Sonic using a different image in the even and odd frames. This video sample shows how this interlaced video will be deinterlaced, with a separate frame per field, effectively halving the height of the video stream and doubling the framerate. Here's some images showing what this looks like:
Interlaced:
Image
De-interlaced Odd Field:
Image
De-interlaced Even Field:
Image

On the videos I've shown (not the images) there's an extra border region at the top of the video. This border extends each field to be 262 lines high, and will hold the VITC video content for the Laserdisc video. This is image data that's present on the real disk, but is normally completely hidden in the vertical blanking region, and no capture card I've seen can actually capture it as image data. I've found it very hard to find a good image of visualized VITC data online, but here's a poor one:
Image

I can easily view this timecode data with a sony PVM monitor that has a H/V delay function, but capturing it on the computer is a little tricky. My current plan is to force a bad vertical sync into the video signal in order to force these lines into the visible region of the display, and combine it with the proper ripped video stream in order to populate these upper lines of the video content. I think this part will be very hard for other people to reproduce unfortunately.

doc eggfan
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Re: MegaLD Dumping Project

Post by doc eggfan » Sat Jan 25, 2014 7:01 pm

Hello all,

I have the following, which I'm in the process of sending to Nem this week. He's also doing me a favour by replacing the caps on my PACs.
  • -3-D Museum (Japan) [SEGA]
    -Ghost Rush! (Japan) [SEGA]
    -High Roller Battle (Japan) [SEGA]
    -Hyperion (US) [SEGA]
    -I Will: The Story of London (Japan) [SEGA]
    -Melon Brains (Japan) [SEGA]
    -Pyramid Patrol (Japan) [SEGA]
    -Road Prosecutor (US) [SEGA]
    -Rocket Coaster (Japan) [SEGA]
    -Space Berserker (US) [SEGA]
    -Time Gal [SEGA]
    -Triad Stone (aka Strahl) (US) [SEGA]
Image
Last edited by doc eggfan on Mon Jan 27, 2014 8:43 pm, edited 1 time in total.

ICEknight
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Post by ICEknight » Sun Jan 26, 2014 3:29 pm

"Power Drift & Mega Drive"? What is that cool thing?

MNc99
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Post by MNc99 » Sun Jan 26, 2014 7:26 pm

I just want the board to know how happy I am that the right people are finally getting this solved.
The Mega-LD remains a complete mystery to me and it's absolutely fantastic to know its secrets are finally coming out.

You're a fantastic bunch and I wish you every success.
Image

doc eggfan
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Post by doc eggfan » Mon Jan 27, 2014 3:04 am

ICEknight wrote:"Power Drift & Mega Drive"? What is that cool thing?
It's just a laserdisc video - not interactive. Might be worth getting Nem to dump it though so I'm including it. It shows all the bonus tracks and vehicles.

doc eggfan
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Post by doc eggfan » Mon Jan 27, 2014 8:29 am

I'm just curious, just how pornographic are the porno games? They'd be just soft core voyeurism stuff right - just girls in various stages of undress? I can't imagine them being too full-on

This is in no way meant to condemn nor convince Nem to change his 'no porno' rule, I totally respect where he's coming from, I was just curious about them.

ICEknight
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Post by ICEknight » Wed Feb 05, 2014 9:31 pm

Kind of related, there's some discussion going on at the MESS forumsregarding the dumping and storing of analog media (VHS tapes, in that case).

LAPProject
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Post by LAPProject » Sat Feb 08, 2014 8:53 pm

It looks like i'm problably a spammer has been brainwashed by 3D Museum...

As for the porn games, they're pretty pathetic. Gambling, photographs, etc., all the things you'd usually find in early 90's eroge, except this time using FMV because they could afford to. A lot of the porn games (Virtual Cameraman and Pretty Illusion, I think) got ported to the 3DO after the LaserActive went bust.

And on that note, two other LaserActive games got 3DO ports... Triad Stone got ported as Strahl, with less video footage but a better soundtrack, and Pyramid Patrol was surprisingly REMADE as Pyramid Intruder - complete with totally new CG footage, and even some very crude real-time 3D stages!

McKie1
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Ebay lot

Post by McKie1 » Wed Feb 26, 2014 8:03 am

For anyone that has won the lotto - http://bit.ly/1cGXmXf

ICEknight
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Post by ICEknight » Wed Feb 26, 2014 6:38 pm

That guy can't be serious.

Chilly Willy
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Post by Chilly Willy » Wed Feb 26, 2014 6:57 pm

He wants about $500 per game, but you have to bid on the entire lot. I'm afraid this is another set that will wind up in the hands of someone who has no idea what they have beyond being expensive.

doc eggfan
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Post by doc eggfan » Fri Feb 28, 2014 10:17 am

He's serious. It's not a bad appraisal of the value of these games - I probably would have gone around the $12,000 mark.

The expectation is that the values will plummet after we've dumped them all, so that's why he's selling. However, if an accurate dump of the analog video is going to be about 80GB, I expect that the video will be compressed to a more manageable size, and thus no longer be "exactly" accurate.

Will an LD dump of Time Gal, after compression, offer anymore fun than the already existing Mega CD dump? I'm sure the video will be much better quality, but still never quite the same as the original analogue

Chilly Willy
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Post by Chilly Willy » Fri Feb 28, 2014 7:08 pm

Dumps of games don't destroy the value. Look at games like Spiderman Web of Fire or DarXide - both have been dumped for years, but actual copies still sell for mega-bucks. The price is in the fact that it's the authentic article. Authentic LDs of any sort retain their value rather well, regardless of anything else.

LAPProject
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Post by LAPProject » Mon Mar 03, 2014 7:38 pm

I'm not so sure about that for all cases... I know that at least temporarily, the market value of Melon Brains took quite a dip after I posted the majority of the disc's footage on Youtube.

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