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Topics - the_ally235

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ROM Hacking Discussion / SPC700 FIR Echo Filter - What Does it Do?
« on: November 21, 2016, 02:52:47 pm »
Okay, to be more specific, I want to know exactly what the format the FIR Filter settings is based off of.
I know it is determined by the fourth hex code in this code (at least for the common Nintendo SPC system)
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F7 XX XX XXI know this much, but then we get to the FIR values themselves. Now, what I am trying to do is get the same FIR filter variables that the SNES version of At Doom's Gate (from the SNES version of Doom, of course) uses, which is this
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FA 0A 1A 13 13 1A 0A FANow, the game I am basing these codes off of is EarthBound, and I know Doom uses a modified version of the normal Nintendo SPC700 sound system, but to what extent I am not really sure, and so does EarthBound, which simply adds in three debug codes. But with that knowledge I know for sure that the two games share the same exact echo settings. And I want to know, how in the hell do you determine what the FIR filter variables are going to be with only the one single hex code that sets them???

So hi.
First of all, here is the music editor in question.
And second of all, I will need to detail what we need exactly.

Okay, so the way EBMusEd renders sound, from what I understand, is pretty much the old and inaccurate ADPCM emulation. Oh, and it doesn't have echo implemented, since when it was first made (which was 2005) we did not understand how the echo effects worked, so no code was ever actually implemented for it. But, what we're trying to do is make the program emulate EarthBound's SPC complier and send the result to a standard SPC plugin. The thing is, we don't have any knowledge of what EarthBound's SPC complier is in the code, as it's not documented anywhere. Plus, I am not sure how we'll be able to program this in. You can look at the source and try to figure it out yourself, the code where it renders the audio is located in play.c and if you want to compile it, use GNU GCC compiler or whatever since (for whatever reason) it was programmed with C and used Make (even though it's meant for Windows systems, why it was done this way is beyond me). I would highly suggest that if you want to program this stuff in yourself (I highly doubt any of you will) that you download v2.2's source code, which comes from github, and load up the .cbp file from in the ide folder using Code::Blocks with mingw installed already, as it should load up all the files properly so it will actually properly compile. If you could at least help out with getting the ASM data for EarthBound's SPC complier, that would be great!

ROM Hacking Discussion / What Are The DOOM SNES Port Music Ranges?
« on: March 06, 2016, 01:42:47 pm »
I wanted to export the music data from the DOOM SNES port, but I'm not sure where it is exactly, besides probably starting at about 0x70000. I would even more appreciate to know what the ranges are for each specific song (like the specific ranges for e1m1/At Doom' Gate). And yes, I DO have reasons for this.

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