hootvopm/README.md

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# hootvopm
This script converts a [Hoot](http://snesmusic.org/hoot/v2/) 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.
## Usage
`./hootvopm.py [-b] -t chip_type 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
* OPM
* OPN
* OPNA (equivalent to OPN)
* Raw data in 32-byte groups (see below)
#### 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.
## 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