Ok, in order to have Game Gear movies accepted, there are at least two points to be sorted out.
Dega is inaccurate
Differentiate GG and SMS roms
About point number 1, I contacted Maxim, one smspower's webmasters, and THE authority then it comes to 8-bit sega consoles. What he says is always correct.
For the record, it should be noted that Dega is overall inaccurate, it's probably the worst SMS/GG emulator of the bunch nowadays, as other emulators (which unfortunately don't support rerecording) such as Fusion, Regen, eSMS, and some others, are much more accurate in general (also with regard to SMS games). But, as Upthorn mentioned, Dega actually have additional palette issues with GG games.
My query to Maxim was the following:
nineko wrote:
Hi, sorry to ask you such a question, but on tasvideos.org someone mentioned that Dega doesn't emulate Game Gear games properly because of its palette...
I know Dega isn't accurate in general, you already mentioned that once, but do you know if there are any significative differencies in the level of accuracy between Master System and Game Gear games?
And here is Maxim's response:
Maxim wrote:
The GG has 12-bit colour but Dega interprets it wrong, I think it truncates it to 9 bit. A good game to compare is FIFA Soccer, its pitch uses close shades of green which look awful in Dega.
It is probably a 5 minute fix for someone who is set up for working on it. Try contacting the maintainer of the TAS version.
So, point number 1 is an actual problem that should be addressed.
Instead, with regard to point number 2, that's a non-problem, as the rom extension is conclusive in this case. I know it seems weird, but the only way to differentiate a GG rom from an SMS rom is to rely on its filename, as the header isn't conclusive (there is a byte, used also for the country, that might be used for this purpose but sometimes it carries wrong information). In fact, all the emulators (afaik), including the ones I mentioned above, rely on the extension to determine if they should run in GG or in SMS mode. This can be easily checked by renaming a .gg rom to .sms and vice-versa. Since the rom format is exactly the same, SMS games will (almost?) always run fine on a GG, and GG games will technically run on an SMS, though the limited color palette and the lack of a proper start button will probably crash or lock up the game before the first screen. This to say that modifications to the mmv format aren't needed, since it already carries the rom name, and the format can be detected by looking for ".gg" and ".sms". Adding a flag would just postpone a check already done by the emulator itself with the same logic.
While I appreciate your efforts, I have very different results about the header indicating a SMSor GG game: except for Public Domain ROMs and hacks, there was a total of 2 false positives for the whole GoodGG set and 0 for the GoodSMS set. Any explanation for this?
Emulator Coder, Site Developer, Site Owner, Expert player
(3575)
Joined: 11/3/2004
Posts: 4754
Location: Tennessee
Issue #1 is essentially a non issue. When dega detects a game gear rom it changes to the correct screen resolution. As far as palletes it seems to only be an issue for some games (and makes them unplayable). As far as site acceptance, this won't hinder it
Issue #2, using only the file extension is the one that is currently unacceptable.
Shiny seems to have done step 1, get dega to recognize the information in the game header. Step 2 is to have this info recorded into the movie format (in a way that doesn't break compatibility with older .mmv files).
Hopefully we will sort this out soon so that we can have game gear games.
(EDIT: The same thing would have to be added to mednafen in order for us to accept game gear games with it)
About issue #1:
adelikat, the problem isn't the resolution, but the palette depth. Dega fails at reproducing the 12-bit colors of the Game Gear, using 9-bit colors instead (according to Maxim).
About issue #2:
shinydoofy, the headers might be correct, but Dega still ignores them, and relies only on the extension anyway. For example, renaming Sonic Triple Trouble from .gg to .sms, will get you this:
, even if the country code in the header is 7 (GG international).
But sure, this is something that can be implemented, I only wonder why no other emulator checks the header though. I seem to remember there was a legitimate reason to do so, but since I can't remember which it was, I'll assume I was wrong and you were right.
Anyway, adelikat, if adding a flag, it's easy enough to keep compatibility with older movies, since they all are SMS only. Setting a bit to 1 somewhere will do the trick, I think there are a few spare bytes, which are supposed to be 0 by definition right now.
Hey, what about mednafen? It does SMS and GG. But they're not documented because the developer apparently doesn't like the system.
The core is from an emulator called SMS plus. How does that compare to Dega?
Edit: Oh, it's not news.
It appears that those issues had been addressed, see ShinyDoofy's post below my one. There haven't been any official communications about Game Gear being approved now, though, at least afaik. But at least Dega should be accurate now.
, even if the country code in the header is 7 (GG international).
But sure, this is something that can be implemented, I only wonder why no other emulator checks the header though. I seem to remember there was a legitimate reason to do so, but since I can't remember which it was, I'll assume I was wrong and you were right.
Anyway, adelikat, if adding a flag, it's easy enough to keep compatibility with older movies, since they all are SMS only. Setting a bit to 1 somewhere will do the trick, I think there are a few spare bytes, which are supposed to be 0 by definition right now.