LUFS integrated + LRA:
- Reimplement BS.1770 two-stage gating (integrated) and EBU 3342 (LRA) directly
from the cached K-weighted signal, dropping pyloudnorm's two whole-signal
re-filters. Validated bit-equal to pyloudnorm across steady/dynamic/quiet
signals (0.0000 diff). LUFS compute ~1.9s -> ~0.6s (orig 3.8s). pyloudnorm now
only supplies the filter coefficients.
Prefetch on load:
- After a file loads, PrefetchWorker computes the remaining metrics in the
background (sequential, cooperatively cancellable, skips on-demand hits), so
the first switch to any metric is instant. Superseded when a new file loads.
Status slip:
- Workers measure compute time; metricTiming + phase/duration progress messages
drive the slip ("Loaded in Ns - computing X...", "X computed in Ys"). The old
fake percentage (10% then done) is logged but no longer shown.
- shutdown() stops background threads on window close.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Profiled hot spots on a 4-min track and cut the worst offenders:
- Remove BPM: librosa.beat.beat_track ran on every load (~3.7s) for a number no
better than tapping by hand. Dropped from AudioFile + the metadata panel.
- LUFS short-term: replace 474 per-window pyloudnorm.integrated_loudness calls
with one K-weighting pass (reusing pyloudnorm's own filter coefficients) + a
vectorised sliding mean-square. This is true *ungated* EBU R128 short-term
(the old loop wrongly gated each 3s window). Integrated + LRA still use
pyloudnorm's gated calls. ~3.8s -> ~1.9s.
- PSR: reuse LUFS's short-term series (memoised on the AudioFile) + vectorised
sample-peak. ~3.0s -> ~0.2s.
- True Peak: oversample the whole signal once, then an O(N) running max over
windows instead of per-window resample_poly. Bit-identical to the old loop
(max|diff| 0.0000 dB). ~2.1s -> ~1.1s.
- Crest Factor: peaks via the same O(N) running max (last per-window loop gone).
lufs+psr+true_peak: ~9.2s -> ~3.2s, plus ~3.7s of BPM removed from every load.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Mikkeli Matlock