Find a copy of FCEU with background input support.
Start up all 4 (or however many) games in recording mode, starting at reset, paused at frame 0. All games must have the same input configuration. Play exclusively using frame-advance and all games will follow along together.
How do you play multiple games at once with the same input in FCEU? How was it done for the Megaman 3/4/5/6 quadruple run?
Just wondering.
All newer releases of FCEU (0.98.16 and upward) have two features which are essential for TASing multiple games at the same time. They are:
1. Run in background
2. Background input
Run in background basically means that your emulator will still be running, even if it isn't the active window. So if you play a movie on the emulator, and, without pausing minimize the emulator windown, the movie will still keep going.
Background input means that, even though the emulator isn't the active window, all keys you press will still be valid, even for the minimized emulator window. For instance, if you have a movie running, while the screen is minimized, pressing pause will still pause the movie.
Combine these two things, and you can TAS multiple games at once. What you have to do is:
1. Open FCEU as many times as you want games to TAS.
2. Load for each FCEU the game you want to TAS.
3. Pause all games.
4. Go to "record movie..." for each FCEU, and press ok.
5. Enable run in background and background input.
6. TAS like normally.
When stopping, just stop all movies. If you want to resume TASing some other time, repeat the same steps, but instead of recording movies, just load the movies. If you haven't changed your savestates, you can use them... if you have changed them, you should make a new savestate for each game, at the EXACT same frame at each movie.
This will produce as many movies as games you TASed... however, each movie will have exactly the same input. So if you were to load one of these movies for another game you TASed, it will give the wrong rom checksum, but still stay in sync.
Do note that while TASing multiple games, you can't do other stuff in the meantime, like chat or something else that uses the keyboard. All keys you press will affect the emulators. If you really want to take a break, or have something important to do, you must turn of background input for ALL FCEU's you are working with.
Another point to make is that only frame advance really works to progress. If you just let the games play like normally, or even at a low speed, the frames of the different movies will desync, and you won't be producing the same movies then!
Hope this cleared some things up :)
About background input, etc., is there a menu or something in FCEU that enables it? If so, please tell me.
Also, how come you must use frame advance when TASing multiple games? Why will the movies desync when just playing at low speed?
It's under Config if you have 16 or up, and you must reenable it each time you start the emulator...
and yes, even at low speed they will not play frames at the same rate
About background input, etc., is there a menu or something in FCEU that enables it? If so, please tell me.
Something tells me you didn't try really hard to find it:
Zowayix wrote:
Also, how come you must use frame advance when TASing multiple games? Why will the movies desync when just playing at low speed?
Well, if you just play at a low speed, one movie might end up a few frames ahead of the other movie. This means that if you give input, it won't be at the same frames for all movies, which will make the movie desync if you play it back. I can't really tell you why the frame numbers don't stay the same at normal, or low speed. Someone else will have to answer that. For me, it's enough to know that they do, and only frame advance will garantee that the frame numbers stay the same (and I'm talking about pressing frame advance for each frame, and not holding it).
