Fix clipped audio

When a recording is too loud for the recorder, every peak above its limit is cut flat. You hear it as crackle or harsh distortion on loud words, laughs and drum hits. In a waveform the flat tops are easy to spot: rows of samples stuck at the same, highest value.

AudioRinse marks the flattened samples and rebuilds them with sparse declipping (A-SPADE). For each 43 ms of the recording it finds the simplest sound, the one with the fewest frequencies, that matches every sample that wasn't clipped and rises past the cut-off wherever a peak was flattened. Sound is mostly a few strong frequencies at a time, so the peaks it draws come close to the ones that were lost.

Rebuilt peaks go above the old cut-off, often above the loudest level a file can hold, so the result is lowered just enough for its highest point to sit at −1 dBTP.

It repairs digital clipping: peaks cut flat inside the recorder or the file. Distortion that happened before that, from a microphone or preamp overloading or a guitar amp, isn't flat-topped, so there's no lost peak to rebuild. Very heavy clipping, where most of the waveform is flat, gets much better but can't come back fully.