[realusername]

Should the re-created code be considered as a derivative in copyright terms?

It's kind of a gray area to me as there's so much work on interpretation involved in decompilation. It's very unlikely the decompiled code looks anything like the original source code.

It would be nice to have a leak of the original source code someday to compare but I'm betting it's very different.

On librw, it's a clearer since it's a reimplementation.

[ThatPlayer]

I don't think you would be able to convince a court of that because analogies will be made to existing types of works.

Would an adaptation of a book to a movie be any different? One that involves interpretation and thousands of man-hours in set design, actors, special effects, director, etc.

You can additionally argue it's a translation. From machine code to readable source code. Translation are directly covered by copyright law already.

[realusername]

Unlike a book or a movie, the people doing the interpretation do not have access to the source material.

The best analogy for me is a reproduction of an artwork without using it as a base material and that would not be covered by derivative laws I think.

> You can additionally argue it's a translation. From machine code to readable source code. Translation are directly covered by copyright law already.

What's under copyright isn't exactly the binary, it's the translation of the source code to the binary because the source code is what's copyrighted at the end of the day.

Here the line is much muddier since the end result has nothing to do with the copyrighted work.

[ThatPlayer]

You don't need the source material to be a derivative though. Music covers also fit your definition. Generally done without access to the sheet music (source code). And performed by completely different musicians/singers. They're still covered by copyright.

A song recording copyright is separated into copyright of the performance, and copyright of the underlaying work. "reproduction of an artwork/song" is a derivative, and covered by the copyright of underlaying work without necessarily infringing on the copyright of the performance/expression of a piece of art.

> it's the translation of the source code to the binary because the source code is what's copyrighted at the end of the day.

The translation is considered a derivative work of the source code. And derivative works are copyrighted.

Otherwise GPL would not extend to released binaries. GPL would not be able to require source code release alongside the binaries.

[realusername]

But the goals of music reproduction is to reproduce the original artwork, in case of a decompilation it's an explicit non-goal as it's impossible anyways.

> The translation is considered a derivative work of the source code. And derivative works are copyrighted.

Decompiled code isn't a translation though but a recreation. It's impossible to use freshly decompiled code for any purpose and there's zero chance any of the original code looks like this.

In music terms it's more akin to an reinterpretation and that wouldn't be a derivative either as far as I know.

The musical equivalent would be to create a music sounding similarly enough to old mario games which would make you remember the games but without being a derivative by itself as it never used any of the originals. And as far as I know, in music you are allowed to do that without being a derivative, otherwise all copycat rock bands of the 80s would be under the same copyright.

[ThatPlayer]

> It's impossible to use freshly decompiled code for any purpose

But it is not useless, otherwise you wouldn't decompile it in the first place. Creating a reinterpretation of software without looking at the decompiled code is fine, that's what OpenMW or Wine do.

> The musical equivalent would be to create a music sounding similarly

That's a parody or homage though. And still not the same, I'd argue cover songs are reinterpretations. Say I do a Jazz cover of a theme from Mario.

> But the goals of music reproduction is to reproduce the original artwork, in case of a decompilation it's an explicit non-goal as it's impossible anyways.

If my goal is to make a movie, and I "decompile" a movie into a script, that won't perfectly match the original script. I'd have to add my own stage directions, set descriptions, etc. And of course the original film never 100% matches the original script. Is that movie now somehow not Harry Potter and the Goblet of Fire?

[realusername]

> But it is not impossible to use it, otherwise you wouldn't need it. Creating a reinterpretation of software without looking at the decompiled code is fine, that's what OpenMW or Wine do.

Sure that's also possible, that's also what librw (Renderware engine) has done here for GTA3 and Vice city, only the game code itself was decompiled, not the game engine.

But then again, it's not because you use the binary that it makes it a derivative of the original source code. The conversion of source code to binary loses tons of information, it's a destructive process.

> If I "decompile" a movie into a script, that won't perfectly match the original script. I'd have to add my own stage directions, set descriptions, etc. And of course the film never 100% matches the original script. Is that script now somehow not Harry Potter and the Goblet of Fire?

I'd say no, that's a different movie script.