ndarray-wav

Read RIFF WAVE files as ndarrays. In future, it will be able to write the data back to .WAVs again.

WARNING - it's not exactly ready for wide use, because I'm just developing it for myself.

Current limitations

It only reads 32-bit floating-point data right now. This is pretty easy to fix, though, so if you need it just raise an issue and I'll put in any PCM type you like.

API

var ndarrayWav = require('ndarray-wav');

ndarrayWav.open('input.wav', function (err, chunkMap, chunkArr) {
    var format = chunks.fmt;
    var arr = chunks.data;
    assert(format.channels == arr.shape[0]);
    var numSamples = arr.shape[1];
});

What? "Chunks"?

WAV files are organised into chunks. Each is labelled with a four-character ID (the main ones being "fmt " or "data").

This ID is stripped of whitespace and placed in chunkMap (second argument in callback). Additionally, chunkArr is an array that holds the same chunks in the order they appeared in the file.

Chunk parsers

You can add parsers for particular types of chunk (e.g. bext for the broadcast-extension chunk). It works like this:

ndarrayWav.addChunkParser('bext', function (buffer) {
    return buffer.toString('ascii');
});

You can register more than one parser for a particular type of chunk. If you return something true-ish, then it stops, otherwise it continues. Parsers are tried in reverse order (most recently-registered first).

This is actually the mechanism that is used to parse the format and wave data (fmt and data).