This page builds a two-second seamless sine loop from scratch, measures it,
marks its loop points on the waveform, and exports it as a WAV you can
download — press play and it should repeat with no click at the seam. Under
the hood, createLoopBuffer builds a 4×0.5 s 440 Hz sine loop
buffer (post-repair: constructs the AudioBuffer directly — no more leaked
live AudioContext per call); metric badges are asserted against sine theory
(RMS 1/√2, peak 1.0, ZCR 2f/sr); the export badge encodes the buffer through
exportBufferAsWav (io/wav tier) and re-decodes it in-page with
decodeWav; loop markers come from
defineMultipleLoopPoints. Metric math node-verified 2026-07-02
with a duck-typed buffer (rms 0.70711, peak 0.9999998, zcr 0.019944).