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Loggiing a DJMain system

Technical discussion about the VGM format, and all the software you need to handle VGM files.

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  • SaxxonPike Offline
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Loggiing a DJMain system

Post by SaxxonPike »

Hey all,

I'm looking to log music from a DJMAIN board, which has a number of Konami's rhythm games.

The DJMAIN board contains a 058141 sound chip, which is basically two 054539 chips in the same package. Does the VGM format support playing back a log of dual 054539? Or does it only support one?

Thanks~
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  • drdevil Offline
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Post by drdevil »

Yes, the VGM format supports dual K054539.
I'm HarmoDevil. Formerly Dr Devil, but I still use the drdevil username here.

Check out my Soundcloud.

I might get back to VGM ripping someday.
  • SaxxonPike Offline
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Post by SaxxonPike »

Excellent! Thanks for the prompt reply. Incidentally, I didn't scroll down far enough in the spec to realize there was a section specifically for dual chip support.

I'm also happy to see support for YMZ280B since that is in use by the Firebeat hardware (beatmania III). Shame there isn't RF5C400 listed, which would be required for the much more popular IIDX series of games.

I hope to compile a complete OST for these games in VGZ format.
  • ctr Offline
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Post by ctr »

Don't expect the Beatmania series to 'just' work since they load music and samples from a hard drive into RAM. For the chips supported (054539, YMZ280B), MAME will only copy into the vgm files the ROM directly connected to the chip. You'll have to manually extract the samples from RAM whenever data is loaded and add then them to the vgm files as ROM blocks. Same deal as with the Namco C219 (NA-1/NA-2).
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  • 2ch-H Offline
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Post by 2ch-H »

I tried before, but the silence of vgm was generated.
Probably I think that difficult.
Because it plays sound effects (musical instrument) during playback the Stream (like a MP3).
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Post by SaxxonPike »

2ch-H wrote:I tried before, but the silence of vgm was generated.
Probably I think that difficult.
Because it plays sound effects (musical instrument) during playback the Stream (like a MP3).
I've written tools to convert these to BMS, which involves decoding the sample data and note charts anyway. I imagine it should be easy enough to look at how the registers are written during gameplay and imitate it.

The sample data can vary quite a lot- 4bit DPCM, 8bit and 16bit samples are all used. Should these be kept as-is or should they be upsampled?
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Post by ctr »

Generally we only accept packs directly logged from the game. Packs created using tools like SMPSPlay and mod2vgm are usually not accepted, but I guess we can make exceptions... Anyway, since VGM files use the same sound chip as the arcade game, the samples should be in the same format. There is no need to upsample them... I don't know how much you've reverse-engineered the games, but if you find the sample metadata tables (ie start/end addresses and sample rates), you can use that when creating the vgm files.
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Post by SaxxonPike »

ctr wrote:Generally we only accept packs directly logged from the game. Packs created using tools like SMPSPlay and mod2vgm are usually not accepted, but I guess we can make exceptions... Anyway, since VGM files use the same sound chip as the arcade game, the samples should be in the same format. There is no need to upsample them... I don't know how much you've reverse-engineered the games, but if you find the sample metadata tables (ie start/end addresses and sample rates), you can use that when creating the vgm files.
The whole thing is mapped out. Chart format, sample format, sample channel/volume/panning assignments, offsets and lengths, the works.

I assumed that something crafted like this wouldn't be accepted for a pack submission, but given how good the VGM plugin plays back other game soundtracks on the same chips, it's still probably the best format for storing these in-game songs.

Think I've got enough information to get started. Code and research that comes out of this project will be available via Github.

Thanks!
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Post by ctr »

Sounds nice. I'm actually working on a quite similar project. Perhaps you'll find it interesting when I release it, which will be pretty soon.

Also, you can always release always your packs in the homebrew forum, as it needs some love...
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