Any news of a Dreamcast' ScummVM port using latest dev...?

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John the adventurer
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Any news of a Dreamcast' ScummVM port using latest dev...?

Post by John the adventurer »

Hello,

recently a friend gave me a Dreamcast and I'm buying in ebay and second hand shops his best games.

I was seen the nice homebrew this system has, ScummVM looks really nice on my non-HDTV tv screen but I'm a bit disappointed with the ScummVM port: It's ok but Dreamcast can do A LOT more.
I think there are not enough effort in Dreamcast port, I know that people can say me "if you don't like it, do it youself", it's not a matter of skills by the maintainers of the Dreamcast port, it's more abandoning it and not updating the homebrew dev tools and using legacy stuff like libronin, it's better a new KOS with SDL, even a lot more portable (less specific platform code).

If it's possible to donate money specifically for Dreamcast port, please say it, because I want incentivate the improvement to the Dreamcast port.

fingolfin
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Post by fingolfin »

I never had a Dreamcast myself and am not involved with the port, but when reading unspecific posts like yours, I immediately get curious and just have to ask it...

When you say: "Dreamcast can do A LOT more" -- what exactly do you mean? What could it do more? If you list the features you are missing, there is at least a chance somebody can implement them... if you don't, well, you just have to pray and hope somebody by chance has the same idea as you have... :-)

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MetaFox
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Post by MetaFox »

I'm curious as to what the original poster meant when he posted that as well.

Almost every game supported by ScummVM can be completed in ScummVM for Dreamcast:

Maniac Mansion, Zak McKracken, LOOM, Indy3, Indy4, Monkey Island 1, Monkey Island 2, Sam and Max Hit The Road, Day of the Tentacle, Beneath a Steel Sky, Flight of the Amazon Queen, and (presumably, as I haven't tested these games personally) Gobliins, Simon the Sorcerer, Simon the Sorcerer 2, and Inherit the Earth. Not to mention the HE learning games if you should feel so inclined.

The only games that aren't completable are Full Throttle, Curse of Monkey Island, The Dig, Broken Sword 1, and Broken Sword 2.

Broken Sword 2 is completely playable up until you have to swap the discs, as interplatform disc swapping isn't available in the main scummvm branch yet. The Dig and Curse of Monkey Island suffer from excessive drive reading due to the fact that the Dreamcast has to read the data off of the CD since it doesn't have an external storage medium (and it doesn't have enough ram to cache much of the data before hand). Full Throttle is completely playable up until the Flight of the Valkaries Bunny Scenedue to the fact that some scenes in Full Throttle "aren't handled properly on the Dreamcast so it sends negative values for some parameters for whatever reason, so it trashes memory that it shouldn't" (joostp). I haven't personally tried Broken Sword 1, so I can't comment if it's as playable as far into the game as Broken Sword 2.

If you are complaining about the skipping of the speech momentarily, it can't be helped. The Dreamcast has to read data from the CD on the fly. It caches data the best that it can, in order to reduce the skipping, and it does a fine job of it. It's barely noticable (a half a second skip once in a blue moon), so it's not a huge distraction and it's not possible to eliminate completely unless you want to stream the data from your hard drive on your computer using a BBA or building a serial to USB "coders cable".

If you are complaining about the mouse movement, it's meant to be slow when controlled with a directional pad. Use the analog stick for faster mouse pointer movement.

If you're complaining about anything else - I'd like to hear it - as I think I covered everything possible that you could have to say about any possible "problems" with the port above.

And as for your "abandoning" comment above: Marcus still works on the Dreamcast version of ScummVM. His last commit to CVS was just barely over two weeks ago. He uses libronin because he reverse engineered the Dreamcast hardware for that library himself, and has spent many years fine tuning libronin for his needs. Libronin is as feature rich as it needs to be. If Marcus finds something that he needs in the future that libronin needs that it doesn't already have, he'll add to it. Libronin is not "outdated", and a port of ScummVM using KallistiOS would not help anything. If anything, the extra bloat from the larger development library would cause the Dreamcast version to skip even more when playing speech, as there would be less memory to be used to cache data when reading it from the CD. If it used the SDL port to Dreamcast, that would be even more bloat, as it's a layer on top of a layer.

Libronin is head above heels the best library to use for ScummVM.

John the adventurer
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Post by John the adventurer »

I don't know about development stuff, sorry. I was thinked about being abandoned because some friends said me the port needed a lot improving and I was probing it, and seems that.

I mean the slowdowns in most games, the lack of synchronization in speech, the incompatibility with some games, disc swapping et al. Maybe a lot of this stuff could be fixed if compressing the data files with some compression or even if converting them to some format easier for the Dreamcast Graphical hardware (sprites as PowerVR textures?), that is tech stuff I don't know. About mp3/ogg playing and other audio playing, maybe AICA could help a lot if using it for that, I was reading a bit about AICA and I think even is capable to emulate the Roland MT-32 synth.

I can't understand why Dreamcast can't support all those games perfectly when fm towns showed some very good ports of LA games running on it.

Another problem with the port is that Markus is the only one that knows how to dig in that code and other developers seems to having problems even compiling it. Maybe if easier to the other developers, the Dreamcast backend could have more collaborators.

fingolfin
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Post by fingolfin »

It's quite apparent you don't know about development stuff, based on what you write :-).

Since you now at least stated some specific points, I can try to answer some of 'em (MetaFox actually answered some of those in detail, did you read what he wrote?).

Compression: We already offer compression. But even with compression, some games just don't fit onto a single CD. There are limits to how far you can compress data.

Compressed data also has to be decompressed. This takes valuable RAM and CPU power, both of which aren't really abundant on the Dreamcast, I am afraid :-/. So, we do use compression, but it's by no means the solution to all problem.

SCUMM games etc. do not use sprites in the classical sense at all, so even though I have no idea what "PowerVR textures" are, I can say that no, they can't be used to handle "sprites"... :-). Only by doing a *complete* rewrite of ScummVM, from the scratch, would this be possible, at least in theory. Frankly, I'd rather spend that one year of work required for that on supporting more attractive modern platforms ...

As for MP3/Ogg playback: As I understand it, the DC port currently simply uses libmad for MP3 playback. Yeah, maybe a DC specific MP3 player which uses the AICA chip could help. I can't really answer that one, Marcus maybe could (I know that there is AICA based MP3 playback code out there, though).

But emulating a MT-32 ? Forget it; I don't believe this will ever be possible on a DC, even if you do not nothing else (no game play, no graphics). The CPU power (including AICA) and RAM available are *way* to low. I am talking about an order of magnitude too slow here...


The FM-TOWNS version of some LEC games were hand written for that system alone. They didn't have to run on multiple other systems equally well... and the games we are talking about (Zak, Loom, Indy3, Monkey Island, Indy4,..) are all pretty low-end games when it comes to resource usage. They run at 320x200; while Broken Sword 1&2 and COMI run at 640x480 (that's more than 4 times as many pixels per screen); the FM-TOWNS games didn't sport digital music and voice overs; they didn't span multiple CDs.
So your question is a bit like: "Hey, my old 386 was able to run Windows 3.1, why can't my Pentium II/266 run Windows XP ?"


As for KOS: Hm, their website apparently was last updated properly in 2004, and it contains lots of broken links (in particular, I couldn't access their developer docs).... so I have a rather bad impression, I must say... don't see how it improves anything compared to the excellent work Marcus did so far ...


All that said, if somebody wants to work on an alternate / enhanced port on KOS, they are most welcome to do so; personally I am just not convinced yet whether it would be an advantage :-).
Last edited by fingolfin on Sun Jan 08, 2006 6:03 pm, edited 1 time in total.

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cpt. wesker
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Post by cpt. wesker »

strangely enought, but my pentium II 266 MHz could run windows XP with no problem (if you define "no problem" in that way)- just saying :lol:

did someone of you guys tried frying an egg on the interier of your pc? this kind of stuff really bring out memmories...

marzipan
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Post by marzipan »

fingolfin wrote:As for MP3/Ogg playback: As I understand it, the DC port currently simply uses libmad for MP3 playback. Yeah, maybe a DC specific MP3 player which uses the AICA chip could help. I can't really answer that one, Marcus maybe could (I know that there is AICA based MP3 playback code out there, though).
So the DC port finally plays MP3s at last, basically? Although this means of course I'll have to redo all my audio tracks and speech files into MP3 for the time being as I carried OGG ones around for a long time..... would playing OGG take up more memory for the DC????

marzipan
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Post by marzipan »

Oh yeah, and would it be possible to have the DC port use the same GUI as the other ports in the future? The simplistic one it's used for ages seems to have a dodgy game-detection system, plus I don't get why for icons it supports only 32x32 16-colours...... it might even be possible to save ScummVM settings onto the VMU like the PS2 port similarly saves to memory card?

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erwan
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Post by erwan »

all is possible if you it programs...
Only Marcus C and Fingolfin maintain the port

link doc. KOS 1.18 :?
http://gamedev.allusion.net/docs/

Example libronin&KOS(old) :
http://www.atani-software.net/dcprog/

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