A Yankee in ZXDB

[Einar Saukas]

Sorry but it's against ZXDB policy to store hacked, edited or converted screenshots. Only fully authentic screens are accepted. However we will gladly store multiple screens of your game. If you cannot show all sprites in a single screen, this is not a problem, just give us different screens, like this!

Kweepa’s right, saving a frame from Yankee in an emulator into a SCR will leave some sprites unrendered. I think that would look “authentic.” Don’t get me wrong, I understand your policy, but I think you need to be a little more flexible. It’s one thing to slap screenshots from a C64 version of a game on the back of a Spectrum tape; it’s a different matter when the format that you've chosen for the screenshots is simply not suitable for capturing some in-game action.

Problem isn't the format. It's the way most emulators generate it. Most of them will simply take current content of screen memory area, thus including changes in-between frames that shouldn't be visible. It would be more accurate to save instead the screen memory area content from the time currently visible screen was generated.

If you use Fuse 1.4.0 or later, and save your screenshots directly as MLT instead of SCR, then I believe you will get a perfectly accurate screenshot. Then you can use ZX-Paintbrush to load screens in MLT format and export then as a perfectly identical SCR, without any loss.

I'm sorry to disagree, but composing an image using a graphics editor isn't authentic. It's like editing a photograph in Photoshop. The result will probably have much better artistic value, but it would be wrong to claim it's an authentic photograph anymore.

[Nomad]

You could put the wav's on archive.org

[spoilers]But its so difficult to find anything on archive.org your going to need to link to it directly.. I'll try and find it but there was an example of a dump of a audio material that was on archive.org for 8 years or so before someone found it and realized what it was [/spoilers]

[Einar Saukas]

It looks like Bifrost screenshots are PNG

Good point! I added new screenshots in MLT format, but I forgot to remove the old PNG screens inherited from WoS. They will be removed in the next ZXDB update.

[R-Tape]

What exactly is MLT and how does it help here?

My understanding is that it's a .scr with more data for multicolour attributes, so is MLT a Spectrum specific filetype? How does it solve the difference between screen memory and what is on the TV screen at a particular point in time in YIQ?

What does MLT stand for?

Questions!

[Ralf]

What exactly is MLT and how does it help here?

As you know there are some tricks with Spectrum display - multicolor, gigascreen...
You may also want to store images bigger than Spectrum screen 256x192 pixels etc.

Actually there are already file formats existing for all these cases. They aren't well known, well they are practically unknown but they do exist.

Dimitri at ZxArt uses all these formats. See for example the search for MLT (not much result though):

https://zxart.ee/eng/graphics/database/ ... pe:zxitem/

You can also expand the list and check other formats there.

[Ast A. Moore]

Problem isn't the format. It's the way most emulators generate it.

The way I see it, the use of that format as a showcase screenshot itself is also problematic. The idea behind in-game screenshots is to give the user an idea of what the game looks like. Since the format doesn’t include the border, it’s never going to represent what the game looks like on an actual TV screen or a window of an emulator. And what about the games that make extensive use of border effects? So, not the best choice. But I (partially) understand the reasoning behind choosing it.

Anyway, speculations aside, I reuploaded the archive with a new in-game screenshot (same link, see first post). Man, this whole RZX to MLT to SCR business is no walk in the park, let me tell ya . . . ZX Paintbrush was being stubborn refusing to convert the MLT to an 8x8 Spectrum SCR directly, so I had to save it as SCR (which was essentially an MLT with a different extension), then reopen it, then convert it into 8x8, and only then could I finally save it as a proper SCR.

What does MLT stand for?

MuLTicolor. It uses the 8x1 attr format, so the file size is 12288.

[Kweepa]

Yeah, if there's no border, it loses some of the flavour of the game.

[Einar Saukas]

What exactly is MLT and how does it help here?

My understanding is that it's a .scr with more data for multicolour attributes, so is MLT a Spectrum specific filetype?

Correct.

How does it solve the difference between screen memory and what is on the TV screen at a particular point in time in YIQ?

Spectrum multicolor can only be generated by modifying screen memory during image rendering. Therefore when an emulator saves a multicolor screen, it cannot just copy data from screen memory to disk. It's forced to "remember" the original data corresponding to each part of the screen.

Saving screenshots as MLT (in Fuse 1.4.0 or later), even when the game is not multicolor, is just a way to tell the emulator "I don't want a copy of data from screen memory because it may have already changed after screen was generated. Instead, I want a copy of the exact same data you used for screen generation".

Afterwards, it's safe to convert MLT to SCR without losing anything, because this screen won't have multicolor attributes anyway.

What does MLT stand for?

I have no idea! I didn't invent this format, I adopted it exactly because lots of tools already supported it.

It's always better to avoid reinventing wheels unless there's a very good reason to do so.

[Einar Saukas]

The way I see it, the use of that format as a showcase screenshot itself is also problematic. The idea behind in-game screenshots is to give the user an idea of what the game looks like. Since the format doesn’t include the border, it’s never going to represent what the game looks like on an actual TV screen or a window of an emulator. And what about the games that make extensive use of border effects? So, not the best choice.

I know! My own game Knights & Demons DX uses my own Rotatrix but you cannot see it in the screenshots...

It's not a perfect solution, but SCR is the most widely used Spectrum format, and we already had about 30,000 screenshots inherited from WoS archive without border. Adopting a new obscure file format, unsupported by most tools, just to store border information wouldn't be practical, unfortunately.

But I (partially) understand the reasoning behind choosing it.

Anyway, speculations aside, I reuploaded the archive with a new in-game screenshot (same link, see first post). Man, this whole RZX to MLT to SCR business is no walk in the park, let me tell ya . . . ZX Paintbrush was being stubborn refusing to convert the MLT to an 8x8 Spectrum SCR directly, so I had to save it as SCR (which was essentially an MLT with a different extension), then reopen it, then convert it into 8x8, and only then could I finally save it as a proper SCR.

Thank you for your comprehension!!!

[Einar Saukas]

What exactly is MLT and how does it help here?

Actually there are already file formats existing for all these cases. They aren't well known, well they are practically unknown but they do exist.

Actually we use SCR for regular screens, MLT for multicolor 8x1 and IFL for multicolor 8x2. These are all standard formats!

Dimitri at ZxArt uses all these formats.

As a matter of fact, Spectrum Computing displays all these images using the rendering component developed by Dmitri.

There's a lot of cooperation between almost all Spectrum and Sinclair related sites!

[Seven.FFF]

So basically, the first 8x8 SCR is inauthentic, because it's been put through a transformation process to capture what the user saw on the screen in that frame.

But the second 8x8 SCR is authentic, even though it's been captured with a different sampling method and rate, then put through several transformation processes into a file that in principle would contain exactly the same bytes (if it was from the same gameplay instance, at least).

[Einar Saukas]

So basically, the first 8x8 SCR is inauthentic, because it's been put through a transformation process to capture what the user saw on the screen in that frame.

No, it wasn't what the user saw in that frame. It was a composition:

I then grabbed a couple of frames from that GIF, opened them in a graphics editor, and cut and moved the sprites around until I was satisfied with the composition.

[Seven.FFF]

I ran a green sharpie round the edge of my monitor, but the bits didn't sound any better either.