lucasw89/STSheets
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix: final-review findings (median pass tick, R11 secondary metrics, R12 chord duration, render version, dsp resample)

Browse Source 
Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
This commit is contained in:
Lucas Winther
2026-10-30 05:55:04 +01:00
co-authored by Claude Sonnet 5.5
parent 2b7d5ffbeb
commit b631bd2c7e
16 changed files with 199 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/audio/wav.ts
+1 -26
View File
@@ -68,30 +68,5 @@ export async function writeWav(path: string, a: Audio): Promise<void> {
}
export { toMono } from "../dsp/mono.ts";
export { resample } from "../dsp/resample.ts";
const sinc = (x: number) => (x === 0 ? 1 : Math.sin(Math.PI * x) / (Math.PI * x));
/** Windowed-sinc (Blackman) resampler; low-passes at the lower Nyquist when downsampling. */
export function resample(x: Float32Array, from: number, to: number): Float32Array {
if (from === to) return x.slice();
const ratio = to / from;
const outLen = Math.round(x.length * ratio);
const out = new Float32Array(outLen);
const cutoff = Math.min(1, ratio); // in units of input Nyquist
const half = 16 / cutoff; // kernel half-width in input samples (16 zero-crossings)
for (let j = 0; j < outLen; j++) {
const t = j / ratio;
const lo = Math.max(0, Math.ceil(t - half)), hi = Math.min(x.length - 1, Math.floor(t + half));
let acc = 0, wsum = 0;
for (let i = lo; i <= hi; i++) {
const d = i - t;
const w = 0.42 + 0.5 * Math.cos((Math.PI * d) / half) + 0.08 * Math.cos((2 * Math.PI * d) / half);
const k = cutoff * sinc(cutoff * d) * w;
acc += x[i]! * k;
wsum += k;
}
// Normalise to unity DC gain so edges and non-integer ratios stay calibrated.
out[j] = wsum !== 0 ? acc / wsum : 0;
}
return out;
}