Castle Paradox

Bagne · Posted: Thu Oct 22, 2009 2:33 pm Post subject: Music - game synch

How does the timing for midi music work w.r.t. ticks in a plotscript?

Can they be synchronized? I remember somehow concluding that this was not possible using BAM ... I forget why.

What about MIDI?
Does the timing always depend on processor speed, stuff on the map etc. etc. etc?
Or are our machines nowadays fast enough to be reasonably consistent?
_________________
Working on rain and cloud formation

Bagne · Posted: Thu Oct 22, 2009 2:35 pm Post subject:

Oh, and what about ticks in a tile animation?
Those would be the same as ticks in a plotscript, neh?

I always thought it would be cool to get some tiles moving in time to the music.
_________________
Working on rain and cloud formation

Bob the Hamster · Posted: Thu Oct 22, 2009 2:51 pm Post subject: Re: Music - game synch

Accurate music timing is not possible in the OHRRPGCE. You can get your timing reasonably close, but it is not possible to know exaclty which note will play on which game tick. This affects all music formats, BAM, MIDI, OGG, MP3, MOD, whatever. The reason is that music is played in a separate thread from the rest of the engine, so things that slow down the engine do not slow down the game. There are possibly some things we could do to improve the situation for future versions, but certainly nothing that will be ready for the next release.

As for making your timing match more closely with the music, your best bet is probably to rely on the "milliseconds" command instead of wait commands. "milliseconds" reads the system timer, which will remain accurate even if some other factors slow down the game engine.

Maybe something like

Pepsi Ranger · Posted: Thu Oct 22, 2009 6:33 pm Post subject:

I think it's time to reveal one of the The Adventures of Powerstick Man: Extended Edition secrets.

I have three sequences that require and utilize musically synchronized scripts. TMC wrote these scripts for me to make it work:

TMC · Posted: Fri Oct 23, 2009 3:58 am Post subject:

The improvement of waitsecs over James' script is that small errors do not build up over time: the timing is always as good as possible (to within one game tick).

To anyone wondering why there are two scripts, it is because Pepsi had already synchronised some music when I realised that my script was flawed. So I added and tweaked some constant to it so that I could fix the flaw but still stay close enough to the old version to not break the synchronisation. Just ignore waitsecs2 and use waitsecs.

I can not remember why waitsecs uses 57ms a 'tick', which is 17.5 ticks a second when the OHR uses 18.2 ticks a second. Probably the same reason as above. Anyway you can easily modify the script to count in any units you want.
_________________
"It is so great it is insanely great."

Bagne · Posted: Fri Oct 23, 2009 5:09 am Post subject: musical timing

Thanks -
I'll give those a shot.

So that's your visual timing ...
How did you find the landmarks in the music?
Did you just jump into a midi player and find that ...
say ...
There's an important chord at 13.54 seconds - so, that's when I trigger X ?
Or did you manage to assign a length of time to a BAM 1/16 note?
_________________
Working on rain and cloud formation

TMC · Posted: Fri Oct 23, 2009 5:40 am Post subject:

There's a few alternatives. First is trial and error (and probably most important).

I guess you could work out times like you described. However there might be some slight unaccounted lag time when actually playing the music ingame.

Another, you can write a script that starts the music and listens for keypresses, triggering the next event and writing waitsecs calls to g_debug.txt (using trace) when you press a key; these will be rough but you can then clean them up (using trial and error)

You could maybe even insert SYSEX events into a MIDI which set global variables when run in music_native (not sure if these actually work), and run a script which waits for the global to change and then again write to g_debug.txt as above.
_________________
"It is so great it is insanely great."

Camdog · Joined: 08 Aug 2003 Posts: 606

This thread got me thinking...

Would it be possible to include a plotscript command in later versions that returned the number of milliseconds into the current song being played? That way, while it will still be a bit of hack to get the music to sync with the game, perhaps it would be possible to get the game to sync with the music?

TMC · Posted: Fri Oct 23, 2009 6:46 am Post subject:

Our music libraries/backends are very inconsistent feature-wise. I don't like SDL_mixer.
I guess we could manually track the number of milliseconds, but that would actually be nearly identical to doing it via script.
Hey, wow, SDL_Mixer has a SetMusicPosition function, great (but no way to actually GET the music position). I think someone requested that feature but we thought it was impossible. But it's a nuisance that most of the API is not documented!
_________________
"It is so great it is insanely great."