7331Squall
Posts: 2
Joined: Tue Dec 20, 2016 3:12 pm

CD-I emulation cutscene Issues (MESS)

Wed Dec 28, 2016 11:06 pm

Hello, I'm pretty sure this is a very difficult thing to get fixed, but, here it goes.

I'm able to use MAME to emulate a Philips CD-I, as it was something MESS was supposed to do, and it got merged with MAME (so, I'm sorry if i'm posting this on the wrong area)

There's an issue with the infamous Zelda CD-I games, Faces of Evil and Wand of Gamelon, since those games rely heavily on cutscenes that are overlayed on top of the current scenario.

The emulator is able to play those cutscenes.... But as long as you use a very unusual Workaround.

You see, most of these cutscenes are triggered by you making some action, like talking to a NPC, or entering an area via a door.

If you simply talk to the NPC or enter the area, the game hangs until your press another button. Pressing it will "skip the cutscene" and resume regular gameplay.

However, if you trigger the cutscene while holding any of the two buttons the CD-I has.... the game hangs as well, but this time, the cutscene will start as soon as you let go of the button.

Even if you start holding the button after the game freezes (indicating it's loading the cutscene) and before the sprites disappear (which is when the CD-I should start playing it) it'll play correctly. As long as you're holding any of the two buttons when the sprites disappear, the cutscene plays once you let it go.

As this didn't happen in the standalone CDIEmu (which MESS emulation seems to be based off, way back then. MESS got a lot better than it), I'm assuming this is not its correct behaviour.

I know this is a very minor glitch, for a system that's not a major interest of most people, and it's emulation development efforts were probably halted way back in 2009, but... It's still a glitch, and I'd like to see it fixed XD

Oh, by the way, since the beginning cutscene doesn't need special transparent effects until its last 5 seconds, it plays properly even without that workaround. So if you're testing it, I'd say to go to Goronu on FoE or Sakado in WoG, enter the nearest building (the shop in both games) and talk to the merchant (by slashing him with your sword. :shock: Logic.)

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B2K24
Posts: 44
Joined: Wed Mar 30, 2016 5:43 am

Re: CD-I emulation cutscene Issues (MESS)

Thu Dec 29, 2016 9:04 am

Issues with CD-I emulation using MAME are known. The last person who did major work on the driver suggests using CD-i Emulator if an image doesn't work using MAME.

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cdifan
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Joined: Sat Jul 02, 2016 6:37 pm
Location: Netherlands
Contact: Website YouTube

Re: CD-I emulation cutscene Issues (MESS)

Fri Dec 30, 2016 11:04 am

The MESS/MAME CD-i emulation is NOT "based" on CD-i Emulator, but there was some cross-fertilization.

A similar problem used to exist in CD-i Emulator, having to do with improper handling of end-of-file/end-of-record indications from the compact disc. I have no idea if the MESS/MAME problem is related, though, and also no interest in looking into it myself.

-- CD-i Fan (author of CD-i Emulator)

7331Squall
Posts: 2
Joined: Tue Dec 20, 2016 3:12 pm

Re: CD-I emulation cutscene Issues (MESS)

Mon Jan 16, 2017 11:38 pm

cdifan wrote:The MESS/MAME CD-i emulation is NOT "based" on CD-i Emulator, but there was some cross-fertilization.
Welp... I wasn't really sure of it,

Anyhow, it's an EOF issue? Because, the last version of the CDIEmu I tested had no such issue, the only issue it had was not playing any sound effect or music in-game, it only outputted the FMV sounds and the main map screen's music.

I understand you have no interest to look into it, but, how would you rate the complexity of swatting that bug? Something relatively simple, or something that requires a bit of work, or something that involves rewriting a major part of the code...?

i'm asking because... maybe someone else is curious enough to try?

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cdifan
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Joined: Sat Jul 02, 2016 6:37 pm
Location: Netherlands
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Re: CD-I emulation cutscene Issues (MESS)

Fri Feb 10, 2017 7:08 pm

If it's indeed an EOR/EOF issue, the problem will probably be somewhere in the timing and/or disc/play state management. This is relatively intricate code, as it's event driven. However, if you're sufficiently motivated, it should be possible to find and fix.

I'd recommend reading the Green Book section about disc play first, however. You can find it here: https://www.lscdweb.com/data/downloadab ... y94_r2.pdf.

It would also be very helpful to have a system call trace; AFAIK the CD-i driver does not currently support this.

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