Acmlm's Board - I2 Archive - Rom Hacking - SPC Question
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HyperLamer
Posts: 792/8210 |
OK, let's clear this up once and for all.
The SNES uses the SPC-700 Sound Processor to produce sound. This is a full CPU, just designed for audio. Games can upload program code and data to this CPU. Because they use actual SPC-700 programs to play sound, one game's sound format usually differs from others. Compressions may be used, data may be stored in any format desired, and even when uploaded to the SPC-700, the data that produces one sound in one game may sound totally different in another, or even crash the system, if the audio program is different. This is why music can't easily be swapped between games, and why you can't just insert an SPC file into any game.
SPC files contain a memory dump of the SPC-700. The data in these may not be the same as the data in the ROM, since it's the result of any processing (decompression, formatting, rearranging, etc) the game does on its internal sound data. An SPC player simply emulates the SPC-700 and the SNES's audio system. SPC files can't be directly converted to WAV (or MP3, which is just compressed WAV). You can find programs that do it, but what they actually do is play the SPC file and record the sound to a WAV instead of sending it to the speakers. This is why conversion time = song length (unless they play it double speed or something, but this may mess up some songs), and why you can't convert WAV back to SPC. |
Dish
Posts: 70/596 |
Well that's simply playing the SPC. Any music player convers whatever music format you're dealing with to PCM.. which is streamed to the soundcard. Since wav files are nothing but that sound data stuffed in a file... doing XXX->wav conversions is no different than just playing the file normally. |
MathOnNapkins
Posts: 235/2189 |
ditto, although some SPC utilities will go the other way, making a WAV file out of SPC playback and then you can compress that into an MP3. Superjukebox, for example. |
Dish
Posts: 69/596 |
MP3 or WAV? absolutely not*. mp3 and wav files contain the raw pcm data to be output. There's no channel info... no volume info... just a big sound wave contained in a file. SPCs work completely differently. SPC files contain game code which writes to special registers (which all needs to be emulated) to produce tones.
You'd have a lot better luck with MIDI->SPC conversion... but even that would be extremely difficult.
SPC files are not a music format like midi/mod/it/wav/mp3/etc... they're a dump of system RAM... kinda like a savestate. They work similar to ROMs. Wanting to take X sound file and make it into an SPC is like wanting to take a PC game and convert it to a SNES game. It just doesn't work like that.
* I don't want to say it's impossible. It's theoretically possible to do a wav->spc conversion... but you'd have to make a pretty damn complex program to do it and it would probably end up sounding like crap. |
Emptyeye
Posts: 38/2273 |
I don't know the true answer to this, but my understanding is that SPC works similar to MIDI (IE there's no actual "music"; it's the processor telling the sound chip "Do this at this time"). So my guess would the same as the answer to the question "Can you convert MP3/WAV to MIDI?": The short answer is "No." The slightly longer answer is "Probably, but the results wouldn't be worth it". |
Clockworkz
Posts: 921/2002 |
Is there any way to convert MP3 or WAV to SPC format? |
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hukka
