Is it worth getting the LD CHDs in MAME?

[NipRing]

I havent updated my MAME set in a couple of years and i was going to order a new set but now i see that they are starting to include LD games right in MAME...at an extra whopping 65GB of CHD! And thats for ony 4 LD games, there are 13 more games (most likely all the Digital Leisure games: Dragon's Lair, Dragon's Lair II, Space Ace, and Thayer's Quest wont ever make it into MAME). I just dont see them being that great in order to take up that much space. Daphne seemed to be working fine at a fraction of the space. Or am i missing something here?

[SnowKitty]

Originally Posted by NipRing

I havent updated my MAME set in a couple of years and i was going to order a new set but now i see that they are starting to include LD games right in MAME...at an extra whopping 65GB of CHD! And thats for ony 4 LD games, there are 13 more games (most likely all the Digital Leisure games: Dragon's Lair, Dragon's Lair II, Space Ace, and Thayer's Quest wont ever make it into MAME). I just dont see them being that great in order to take up that much space. Daphne seemed to be working fine at a fraction of the space. Or am i missing something here?

well i'd say it's worth it if you willa ctually play the games. and i doubt that those digital leisure games won't make it in, they are very popular.

[Ed Oscuro]

The Digital Leisure people might have asked the MAME team not to emulate their games. MAME has complied with a request in this vein before.

Onto the topic: Bandwidth and hard drive space aren't really all that much of an issue anymore - I've finally got a 1TB drive (although not in use), a somewhat energy-efficient one too.

I'd be interested in trying out some of the Japanese LD games, although given the huge download and small gameplay enjoyment I'd get out of it versus looking up clips on Youtube (for instance), I can't see myself doing this for a number of years.

[Frankie_Says_Relax]

Just get Daphne.

It's such a good laserdisc emulator that Digital Leisure saw what they were doing with it and gave them their approval. It will even download Dragon's Lair, Dragon's Lair II and Space Ace automatically (takes about a day but worth the wait) and allows you easy access to play them if you have the Digital Leisure DVDs for a one-time unlock.

If you install Daphne for Dummies (most of) the rest of the games will auto download and don't require anything special to run.

http://www.laserarchive.com/ddl/

The Daphne MPEG2 LD images aren't anywhere near as large as 65GB and look arcade perfect (no pixelization) on massive screens (I've run mine on my 52 inch TV and they've retained near-perfect quality).

http://www.daphne-emu.com/site3/index_hi.php

[skaar]

That looks sweet - checking it out.

[Frankie_Says_Relax]

Originally Posted by skaar

That looks sweet - checking it out.

I'll put Daphne in this perspective ...

... it's the ONLY freeware program that I've donated money (via an in-software "donation" button) to the software creator based on the quality of what it does.

After about 15 years of half-baked floppy disc/CD Rom/DVD Rom/DVD versions of Dragon's Lair, Space Ace, and other Laserdisc classics (up to and including the recent Blu-Ray re-master) Daphne does for the first time for an "arcade perfect" laser-disc experience what MAME does for games like Pac-Man and Donkey Kong.

It's as close as you'll get to the real deal for next to nothing, and MUCH closer than you'll ever get buying the exceptionally lame Digital Leisure PC versions of the Bluth games.

[rsuryase]

Why are LD CHD images so large? I thought each side of an LD can only contain about 600MB of data and 1 hour of video.

[jb143]

Another vote for Daphne here. I have it set as an additional emulator from my frontend and even figured out a way to select different versions of the games...for instance, Dragon's Lair with and without the Drawbridge scene, as 2 different selections from the frontend.

[Jorpho]

Originally Posted by Frankie_Says_Relax

and MUCH closer than you'll ever get buying the exceptionally lame Digital Leisure PC versions of the Bluth games.

Really? Of course I can understand that the Readysoft floppy versions weren't up to par, but surely after re-releasing them a bazillion times Digital Leisure has gotten it right by now? Not even with Dragon's Lair HD?

[jb143]

I havn't played any PC versions since an old DOS one, but if they're anything like the DVD versions then it's almost annoying to play. Laggy controls and icons telling you when to do something. I could barely make it out of the 1'st screen.

[Tupin]

Originally Posted by Frankie_Says_Relax

Just get Daphne.

It's such a good laserdisc emulator that Digital Leisure saw what they were doing with it and gave them their approval. It will even download Dragon's Lair, Dragon's Lair II and Space Ace automatically (takes about a day but worth the wait) and allows you easy access to play them if you have the Digital Leisure DVDs for a one-time unlock.

If you install Daphne for Dummies (most of) the rest of the games will auto download and don't require anything special to run.

http://www.laserarchive.com/ddl/

The Daphne MPEG2 LD images aren't anywhere near as large as 65GB and look arcade perfect (no pixelization) on massive screens (I've run mine on my 52 inch TV and they've retained near-perfect quality).

http://www.daphne-emu.com/site3/index_hi.php

I'm downloading it right now, it just says it's updating. Wait, I need a DVD to play the games?

[jb143]

The DVD's only verify that you own the game. The actual files are automatically downloaded and set up for you. I found my DVD's for really cheap at a used movies and games store.

[Jorpho]

Originally Posted by jb143

but if they're anything like the DVD versions

I can't imagine why they would be; a PC is a considerably more capable machine than a DVD player.

[Ze_ro]

Originally Posted by rsuryase

Why are LD CHD images so large? I thought each side of an LD can only contain about 600MB of data and 1 hour of video.

Actually, a Laserdisc can only hold 1 hour of video if it's a CLV laserdisc... every LD-based arcade game actually uses CAV discs, because they rely on tricks that can only be accomplished with such a format (or at least, the tricks are far, FAR easier on such discs). CAV disks can only hold 30 minutes of video. Also, I don't believe any arcade machines actually use the potential 600MB of data, instead using standard ROMs to hold the actual game programming.

So why does 30 minutes of video balloon up to 10+ GB in MAME? Well, if you want to know all the gory details, the man to ask is Aaron Giles himself. He posted some notes on his blog that explain some of the issues with laserdiscs quite well (All About Laserdiscs Part 1, Part 2, Part 3, Errata). But basically, the simple answer is that Daphne takes the easy route while MAME takes the more difficult (but ultimately more useful) route.

Daphne takes advantage of the fact that most of these games can be cut into discrete segments, such as the individual animations in Dragon's Lair between necessary user input. Each of these animations is compressed into an MPEG video and shown as needed. That's not good enough for MAME though. For MAME to emulate a laserdisc "properly", it has to hold the entire data for each frame of animation on the disc (since the game could conceivable jump to any one of the 54,000 frames at any time), including some extra data embedded in each frame that isn't normally visible on-screen. MPEG compression is quite aggressive and makes video files quite small, but this can't be used in MAME as it is a lossy compression (eg, MP3 vs. FLAC), and MAME holds the data as separate frames rather than a video anyways. MAME's refusal to use a lossy compression is why (or at least, the main reason why, though there are other contributing factors) 30 min of laserdisc quality video ends up being more than twice as much data as a DVD.

So why would they do this in MAME when it works just fine in Daphne with MPEGs? Well the real answer is that it DOESN'T work just fine in Daphne! The video is poorer quality than the arcade machine (thanks to the compression), and adding a new game takes a ton of extra work cutting up video and keeping track of what has to be shown when. In MAME, ideally, someone could dump all the known laserdiscs in an identical manner, dump the ROMs, and hook them up in the appropriate fashion, and you would get essentially perfect emulation, including video that is of the same quality as the arcade machine, and allowing the program to use the laserdisc in whatever way it feels like without relying on kludges to display the correct video. While Daphne's approach will seem to be "good enough" to just about everybody, it is inherently flawed and will eventually be replaced by MAME as soon as 10GB file sizes loose their significance (which isn't too far away).

While this got a little off-track, to the initial question of "Is it worth downloading these CHDs?" I'd have to say no. At the moment, it's still a lot of data taking up valuable hard drive space for games that you are probably not too likely to play. Eventually we'll all have 100TB hard drives, and 10GB will seem like a drop in the bucket, so I'd say wait until then.

--Zero

[Ed Oscuro]

Dang good post there Ze_ro!

I'd like to point out that although CHDs add up quick, taking just a few won't hog a recent-ish drive. No need to download the complete set and alternates if you have no intention of playing them.

[Jorpho]

Last time I checked the MPEGs used by Daphne were still several gigabytes each - but that was many years ago. I guess things changed somewhere along the way? (And doesn't Laserdisc data use some kind of video compression anyway?)

[Ed Oscuro]

Several gigabytes per game is doable on modern drives.

I don't know what format they're using for the LD games in MAME, but the original video is composite, and so already uses a bit of lossy compression (but analog). MAME probably uses something non-lossy on top of that, something a bit more advanced than RLE.

[jb143]

Originally Posted by Jorpho

(And doesn't Laserdisc data use some kind of video compression anyway?)

I don't think so. Laserdics store analog video much like a VHS. I think some laserdics were time-compressed though, to do something like squeeze 62 minutes of video into 60 minutes so it would fit.

[Harmik]

That was a great post Ze ro thanks for the info, in your opinion is the current version of Mame ready for laser games. Or dose it still need improving in which case are you better off running Daphne at the moment.

[Frankie_Says_Relax]

Damn Ze_ro. That's some serious LD emulation education for the books.

While I don't have a ton of experience with LD emu on MAME, I've been using DAPHNE for years with great success, and I still think (if a users end goal is just straight-up playing the games in an arcade authentic environment) Daphne is as close as you'll get to the "real deal" with the least amount of headaches at the present time.

Even if the DAPHNE MPEGs are compressed/chopped, they're very scale-able with no noticeable loss of image quality. (IMO, and I've run them on upwards of a 52 inch screen via monitor input)

One problem I've noticed with DAPHNE are that there are various versions of DAPHNE compatible LD images out there ... (some of far lesser quality compression/conversion) that could give the impression that in general all games display as poorly on Daphne. Watch out for some REALLY awful conversions of Road Avenger and Cliff Hanger ... there are also great versions of those out there too.

The current LD image builds that Daphne for Dummies pulls down all look/function great, AND there are even some builds of Dragon's Lair and Space Ace for DAPHNE that are ripped from the recent HD versions of the games.

If in the future MAME does nail laser disc gaming better that DAPHNE I'll be happy to add those files to my MAME setup, but presently I happily run DAPHNE in my cab.

[LocalH]

Daphne could avoid splitting up the videos into segments by using I-frame only compression - i.e., each frame is self-contained and does not rely on any previous frame for decoding (as do P- and B-frames). Then they could merely start displaying at the desired frame without having to backtrack and decode X number of frames before the desired one. Or, to balance the filesize, they could map out which frames the games start displaying each segment from, and force those frames to be I-frames, while the frames that aren't directly called by the game (and aren't hard scene changes that would need to be I-frames anyway) can be P- or B-frames (although B-frames suck and should be avoided).