spc2midi-tsuu: A new SPC to MIDI converter

[aikiriao]

(I moved the post from "General VGM Discussion and Software" to this channel. I'm so sorry to re-post.)

Recently, I released spc2midi-tsuu, a SPC (SFC/SNES music file) to MIDI (SMF) converter.
As you may know, it is strongly inspired by spc2midi, created by Gigo and Hill. spc2midi is quite good, but I want to make it easier to create MIDI. Also, VGMTrans is one of the best converters. But, for SPC, it cannot implement pitch bend (slide).

So, I decided to create a new tool. spc2midi-tsuu is a SPC-to-MIDI converter based on a SPC simulator, designed to assign MIDI programs more easily.

The tool is open source and available here: https://github.com/aikiriao/spc2midi-tsuu/releases
And for the tool demo, I converted some Super Puyo Puyo Tsuu songs: https://www.youtube.com/watch?v=aZbZzeUTsjo

Please feel free to ask any questions/suggestions/bug reports!

P.S. (The reason why I posted to this forum)
I posted the same message to Zophar's Domain in the first week of February. Unfortunately, my account was banned as spam. I already asked the administrator the reason why my account was banned. But I cannot receive any message from the admin. I also posted to r/snes on Reddit, but I want more technical advice. So I decided to post to this forum.

[GuiMiTomo]

Nice program! I'll try with some SPCs I have.

[LF222]

Wow this tool is incredible, the customizability of the midi is something ive always dreamed of, especially in tools like vgm2mid. if theres one thing id like to have changed about it, often the previews of the snes instruments are very loud and so it becomes hard to cross compare them when picking midi insturments

[aikiriao]

Thanks for the comments!

often the previews of the snes instruments are very loud and so it becomes hard to cross compare them when picking midi insturments

Agreed, so I added a volume slider to the preview window. This is version 0.1.62:
https://github.com/aikiriao/spc2midi-ts ... tag/0.1.62
Is the fix what you imagined? Please ask me if you have any concern on it.

[LF222]

Thanks for the comments!

often the previews of the snes instruments are very loud and so it becomes hard to cross compare them when picking midi insturments

Agreed, so I added a volume slider to the preview window. This is version 0.1.62:
https://github.com/aikiriao/spc2midi-ts ... tag/0.1.62
Is the fix what you imagined? Please ask me if you have any concern on it.

Awesome, was what i needed, now ive noticed the the midis often drift between "patterns" (sections start earlier or later but note sizes remain the same) this happens with vgmtrans too, so i assume its an issue with the format itself rather than the tools.

[aikiriao]

Thanks for your confirmation.

now ive noticed the the midis often drift between "patterns" (sections start earlier or later but note sizes remain the same) this happens with vgmtrans too

It may not be related, though. SPC simulator-based tools (spc2midi and spc2midi-tsuu) can experience note-on and note-off timing slips due to the simulator's cycle timing issue. VGMTrans can grasp perfect timing if it supports input SPC.
For timing issues, you can reduce them by adjusting the “SPC700 Clock-Up Factor” in Preferences. It adjusts the SPC simulator's clock cycle speed.

[LF222]

Haven't had any luck messing with the clock up so far.

Unrelated but I've noticed SPC files made for SMW hacks tend to crash it. Test cases were Mario's mystery meat and A plumber for all seasons

[aikiriao]

I've noticed SPC files made for SMW hacks tend to crash it. Test cases were Mario's mystery meat and A plumber for all seasons

Thanks for your report! I found it as a bug (some SPCs try to read the echo address register, which was not accounted for).
I already fixed the bug and rebuilt the new tool. This is 0.1.63:
https://github.com/aikiriao/spc2midi-ts ... tag/0.1.63
I’ve checked OST for Mario's mystery meat and A plumber for all seasons, and both could open without clash.

[LF222]

I've noticed SPC files made for SMW hacks tend to crash it. Test cases were Mario's mystery meat and A plumber for all seasons

Thanks for your report! I found it as a bug (some SPCs try to read the echo address register, which was not accounted for).
I already fixed the bug and rebuilt the new tool. This is 0.1.63:
https://github.com/aikiriao/spc2midi-ts ... tag/0.1.63
I’ve checked OST for Mario's mystery meat and A plumber for all seasons, and both could open without clash.

Ah awesome thanks

[LF222]

Sorry to nag, but another feature suggestion, given some games make chords into singular samples, perhaps its worth some kind of dump to chord option? see the plok title theme for example.

also i still cant quite figure out the clock option stuff

[aikiriao]

Interesting. I checked the Plok title theme, and it does indeed use chords recorded as single samples, so that’s a good example. Thank you for the suggestion.

Let me clarify your question: do you mean a simple dump of chord names, or do you want the tool to analyze those single-sample chords and convert them into multi‑note MIDI chords? Automatic conversion to MIDI chords is technically challenging because estimating individual pitches from a single mixed‑chord sample is difficult, making it a more complex feature to implement.

Regarding the clock option: the SPC700 CPU runs at 1.024 MHz, and one 32 kHz audio sample period corresponds to 32 CPU cycles. Sometimes heavy instructions (for example, a DIV instruction that consumes 12 CPU cycles) execute, and instruction timing relative to audio and MIDI can't always stay perfectly in sync. As a result, note‑on/off events derived from the SPC stream may slip. To mitigate this, I added a clock factor option: by default, the SPC runs at normal speed (factor = 1). If you set the clock factor to X, the SPC emulation runs at X times the normal speed, allowing you to adjust and compensate the MIDI output timing.