BIF file parser

parseBif.js

function *parseBif(buffer) {
    const data = new DataView(buffer);

    // Ensure this is a BIF v0.
    if (data.getUint32(0, true) !== 0x46494289 || data.getUint32(4, true) !== 0x0a1a0a0d || data.getUint32(8, true) !== 0) {
        return;
    }

    const separation = data.getUint32(16, true) || 1000;
    const start = 64;
    const end = start + (data.getUint32(12, true) << 3);

    for (i = start; i < end; i += 8) {
        yield {
            seconds: (data.getUint32(i, true) * separation) / 1000,
            bytes: buffer.slice(data.getUint32(i + 4, true), data.getUint32(i + 12, true))
        };
    }
}