hootvopm

This script was initially made to convert a Hoot memory dump into an .opm instrument pack, suitable for the VOPM VST plugin. It's an extremely rudimentary way of extracting FM instruments from games, but it works.

Over time, though, I've found myself slowly turning this into a general Yamaha 4op rip-o-tron.

Usage

./hootvopm.py [-b] -t format input_file

Input file can also be - to read from stdin.

Output is dumped straight to stdout; redirect it to a file if you want to save it.

Pass -b to instead read straight binary data instead of comma-separated values.

Currently-supported chip types and formats

ID	Description
opm	OPM register area
opn	OPN register area
opna	OPNA register area (similar to OPN but has 3 more instruments)
raw	Raw data in 32-byte groups; see table below
solfeace	Format used in Sol-Feace for X68000 ("SOL.VCE")

Raw data format

Offset	Value
0x00	DT/MUL*
0x04	TL*
0x08	KS/AR*
0x0C	AMS-EN/D1R*
0x10	DT2/D2R*
0x14	D1L/RR*
0x18	FL/CON
0x19	AMS/PMS

Rows marked with * are groups of 4 bytes, one per operator.

Capturing memory in hoot

• Left- and right-clicking the "driver work" area flips between available memory pages. Scrolling the wheel in this area scrolls through the current page; you can also use Ctrl-(Up/Down/PgUp/PgDn) for this purpose.
• When you see the area you need to capture, use Ctrl-C to copy it to the clipboard. This copies the entire page to the clipboard in a human-readable format, with 16 comma-separated hex bytes per line (plus a comma at the end for whatever reason, but this is ignored).
• Paste this into a file, trimming it down to get the register area of the FM sound chip. Save it as whatever.

Tips

• Most chips (read: all of the ones currently supported by this script) have a 256-byte register area, meaning you'll need to trim it down to 16 lines.
• From what I've seen, the chip's register area almost always resides on the first page, starting either at 0x0000 or 0x0100.
• This should be obvious, but for the formats that don't involve capturing the register area, you should pass -b.

Known issues

• Since the script looks at a simple static memory dump, it has no way of capturing certain data, instead replacing it with placeholders. These include:
  • LFO data
  • Operator on/off state; all operators are considered to be in use (this could potentially be inferred, though)
  • Panning, though VOPM doesn't seem to use this