🎮🎶 spc-converter

Node.js library and command line program to convert Super Nintendo SPC files to WAV files or PCM data.

Use as a command line program

Install

npm i -g spc-converter

Use

Convert to WAV file

spc-converter file.spc file.wav

Outputs file.wav.

Options

spc-converter file.spc file.wav --length=120 --fade=5000 --rate=44100

• --length: How many seconds to play the song for before it fades out. Defaults to the length in the file's ID666 tag, or 150 seconds if it doesn't have one.
• --fade: How many milliseconds the song fades out for, after its length. Defaults to the fade in the file's ID666 tag, or 8000 if it doesn't have a length.
• --xid6-length: Take the song's length from its xid6 tags instead of its ID666 tag, if it has them. They're more exact, but are wrong in many files.
• --silence: How many seconds of silence end the song early. Defaults to 6. Use 0 to always play the whole length.
• --rate: The WAV file's sample rate. Defaults to 48000. The Super Nintendo's own is 32000, which needs no resampling.
• --no-amplification: Ignoring the amplification in xid6 tags.

An option that isn't one of these (like --lenght=10) is an error, which suggests the option you may have meant.

Use in Node.js

Install

npm i spc-converter

Use

Convert a SPC file to a WAV file in your own Node.js script:

const fs = require('fs')
const file = 'file.spc'

// initialize SPCPlayer module
const SPCPlayer = await require('spc-converter')()

// convert SPC file to WAV Buffer
const wavBuffer = await SPCPlayer.renderToWavBlob(file)

// write to file
const outputFileName = file.split('.spc')[0] + '.wav'
fs.writeFileSync(outputFileName, wavBuffer)

You can also use this library to convert a SPC file directly to PCM audio:

const file = 'file.spc'

// initialize SPCPlayer module
const SPCPlayer = await require('spc-converter')()

// convert SPC file to PCM Buffer
const pcmBuffer = await SPCPlayer.renderToPCMBuffer(file)
console.log(pcmBuffer) // then you can do something with the PCM audio data

The PCM audio is interleaved stereo 32-bit floats at 48000 Hz, as the bytes of a Uint8Array.

Both functions take a file path or the file's bytes, and an optional object of options:

• lengthSeconds: How many seconds to play the song for before it fades out.
• fadeMilliseconds: How many milliseconds the song fades out for, after its length.
• xid6Length: true to take the song's length from its xid6 tags instead of its ID666 tag, if it has them. They're more exact (an intro, a loop played a number of times, and an end, to 1/64000th of a second), but are wrong in many files, which is why game-music-emu ignores them.
• silenceSeconds: How many seconds of silence end the song early. Defaults to 6. Use 0 to always play the whole length.
• sampleRate: The sample rate to convert to. Defaults to 48000. The Super Nintendo's own is 32000, which needs no resampling. Converting to other rates uses a windowed sinc filter, which doesn't add the distortion simpler resampling does.
• amplification: false ignore the amplification in its xid6 tags.

const pcmBuffer = await SPCPlayer.renderToPCMBuffer(file, { lengthSeconds: 120, fadeMilliseconds: 5000, sampleRate: 32000 })

Songs play for as long as their ID666 tag says (in either of its text or binary formats), then fade out for as long as it says. Songs whose tag doesn't say how long to play, including files without a tag, play for 150 seconds then fade out over 8 seconds, as game-music-emu does. A song that goes silent for 6 seconds ends there (keeping a second of the silence), also as game-music-emu does, so songs that finish sooner than their length don't trail off into silence. To find out how long a song will be without converting it (at most, since whether it goes silent sooner can't be known without playing it):

const { lengthSeconds, fadeMilliseconds } = SPCPlayer.getSongLength(file)

Development

Install Node.js and either Docker or Emscripten.

1. Clone this repo.
2. npm ci
3. git submodule update --init
4. npm run build
5. npm t