- Wheel zoom around the cursor on both curve plots and the spectrogram:
Ctrl zooms time only, Shift values only, scrolling over an axis zooms
that axis; drag pans live; double-click resets. The zoom window survives
redraws, overlay changes and resizes, and resets when units change.
- Guide and reference lines are painted in a uPlot draw hook, so a dragged
reference line (now with a triangle handle and label) follows the cursor
instead of jumping on release. Per-track integrated lines take the
track's colour when overlaid.
- In-plot legend like pyqtgraph's: a swatch per track plus LRA / max dBTP.
- Metadata shows integrated loudness, LRA and max true peak (prefetched
first) instead of debug rows; the file list shows each track's LUFS.
- UI, canvas and axis text prefer M PLUS 1 Code, else the system font.
- Spectrogram image is cached offscreen so panning is cheap; its tick
labels adapt to the zoom level.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015UXA39Sh9coAx4FhRkd8R2
The FastAPI backend kept one analysis session shared by every visitor and
spooled each upload to the server's /tmp, and the browser copied audio into
persistent OPFS storage. None of that fits a tool for unreleased masters, so
the web UI is now a static site that decodes and analyses in the tab:
- web/decode.js: WAV/AIFF PCM and float read directly with libsndfile's
scaling (bit-identical to librosa.load; Chromium's WAV decoder scales
positive int16 by 1/32767), other formats via decodeAudioData on an
OfflineAudioContext at the header-sniffed native rate. ID3 song names.
- web/dsp.js: ports of every Metric.compute with the same numerics
(pyloudnorm K-weighting via lfilter's DF2T recurrence, BS.1770 gating,
EBU LRA, resample_poly's Kaiser filter for true peak, librosa.stft and
amplitude_to_db), streaming passes with no signal-length intermediates.
- web/metrics.js: build_spec ports producing the existing plot payload.
- web/analysis-worker.js + app.js: per-tab track list and result cache, a
worker job queue where the visible metric jumps background prefetch, and
the renderer, which now also draws the metrics' own reference lines.
Deployment is nginx-unprivileged serving web/ read-only with
Content-Security-Policy connect-src 'none', so the page cannot make network
requests at all, and no access log. No secure context is needed, so plain
http on a LAN works. The Python web backend, its smoke test, the web extra
and the OPFS store are removed; the desktop app is unchanged.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015UXA39Sh9coAx4FhRkd8R2
mikkeli