mameInpFileTools

This repository contains tools for manipulating MAME .inp captured-input files, generated using the -record command-line option.

The tools are implemented in JavaScript, for use under Node.js. They require no external dependencies.

Unwrinkler

If, while playing a game in MAME with input recording enabled, you perform a save-state restore (F7), the resulting .inp file will choke on playback, with MAME reporting Playback Ended, Reason: Out of sync at the moment the first restore takes place.

The unwrinkle.mjs script is a tool that fixes such files by removing input log entries rendered moot by the restore, creating an .inp file that can continuously play back.

To use, install Node.js on a Unix-like environment, and run:

./unwrinkle.mjs (input filename) [optional output filename]

Decoding, manipulating, and encoding

If you want to create your own tools for manipulating .inp files, you might find these source files useful:

• decode.mjs exports a function that parses a Buffer into an abstract representation.
• encode.mjs exports a function that creates a Buffer, using the same abstract representation as the decoder.

There’s also bobbler.mjs which shows how the encoder/decoder can be used to convert inputs specific to one game into ones usable by an otherwise incompatible game.

Compatibility

• .inp files tested on MAME v0.269, under macOS
• JavaScript tested on Node.js v18.15.0

License

The files in this repository are in the public domain.