Three lessons worth more than the scenes: a slow axis has to move a large
low-frequency area or the camera's own drift beats it, whole-frame luminance on
the kick is the strobe the flash gate exists for and it arrives by accident, and
a style trait expressed only as grain measures as no style at all.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Halftone Misprint is a printing fault rather than an electronic one — the image
is never damaged, only separated and reassembled out of register, and nothing
else in the library is made of dots. Droste Feedback scales the previous frame
where Time Smear translates it, so the image never clears. Analog Wow is the
continuous, wet counterpart to Scan Tear and Block Mosh: the error varies
smoothly down the frame because every line was written at a different moment.
Three things that had to be got right. The halftone ruling is a count of dots
across the frame, not a pixel pitch, or a 4K export is the same dot on a bigger
sheet. The Droste loop has to CONTRACT — expanding pushes every copy off the
edge and leaves a plume instead of a corridor. And all three expressed style
only through grain at first, which is the Side Quest 1 complaint: they now put
the track's line weight and edge softness into the dot, the ring and the band
boundary, taking the measured style response from 24/11/18 to 86/255/88.
Neither feedback scene declares a slow axis, with the numbers recorded in the
files: their own history moves the ten-second average further than any parameter
does.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
"Twenty-three of sixty-one scenes are never cast" was an artefact of the song it
was measured on. synthesizeSectioned has one change point, so it segments into
exactly two sections and both are quiet kinds — and intro, breakdown and outro
are restricted to the restful families for every director. Half the library was
unreachable before a seed was drawn, and the measurement reported that as a
casting failure.
synthesizeArrangement builds a real one: intro, build, drop, breakdown, drop,
outro, shaped to hit the segmenter's own classifier rather than to sound like
anything. Measured against a bank of those, two scenes out of sixty-one are
never a background, not twenty-three.
The census exists because "never cast" without a reason is unactionable. A scene
can die at the signature gate, at the director's family table, or in the roster
draw, and those are three different repairs — a trait declaration, a table, and
arithmetic that neither fixes. It reports which one, and it separates being cast
as a background from appearing as a translucent overlay, because a library can
look fully used while nine scenes carry every frame.
What it finds is that eligibility is almost entirely a function of how many
traits a scene declares. Four-trait scenes are eligible for every track and open
half of all videos; two-trait scenes are eligible for one track in fourteen; the
single scene declaring one trait is eligible for none, ever.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A track now yields a complete, coherent look with no input: palette,
per-section scene assignments, parameter sets, post and feedback settings.
Seeded from a hash of the decoded PCM, so a file always renders identically.
- palette.js builds in OKLCH, not HSL. HSL lightness is not perceptual, so
evenly-stepped HSL palettes have colours that vanish and colours that
dominate — which matters when nobody is supervising the choice.
Regenerates until the contrast floor is cleared.
- Scenes are assigned per section KIND, not per section: a track's drops
share a scene and the video reads as one piece instead of a shuffle.
- Family preference per kind keeps breakdowns off strobing glitch scenes.
- Section bias (energy/density/motion) carries track character into params
without scenes knowing anything about audio.
- PaletteSource is the seam for cover art later; no scene would change.
Gate 9/9, including the look-space spread measurement (mean pairwise
distance 0.168 against a 0.08 floor) — the one check that catches a
generator that is deterministic and valid but visually collapsed.
Known gap, not a regression: all four battery tracks currently choose the
same two scenes. There are no 'minimal' family scenes yet, so intro and
outro sections fall through to flow/organic. Differentiation is presently
carried by palette alone. Phase 7 grows the library to fix it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Whole-track analysis into a frame-indexed FeatureTrack. Nothing reads a
live AnalyserNode: realtime preview maps currentTime to a frame index,
export counts frames, both read the same rows.
- fft.js: radix-2 with precomputed tables, allocated once per track
- analyze.js: STFT at hop 1/60s with CENTRED windows (a window that starts
at the timestamp reports energy arriving up to 23ms later, which reads as
visuals lagging the music). Energy features normalised against the track's
own percentiles; absolute stats kept in summary for the look generator.
- tempo.js: autocorrelation + grid F-measure, beat grid, downbeats
- segment.js: self-similarity novelty, boundaries snapped to the bar grid
- FeatureTrack: assembles everything, plus the lookahead fields. buildSlope
rises through the bars leading into a higher-energy section, so a build can
ramp into the drop rather than react after it lands.
- clicktrack.js: mixes clicks onto the detected grid for validation by ear
Three real bugs found and fixed by the tests:
- 174 BPM read as 87. Mean-energy-per-beat scores a half-tempo grid
identically to the true one; only an F-measure penalises the missed
onsets via recall.
- 90 BPM read as 180. Offbeat hi-hats make a double-tempo grid score
perfectly on both precision and recall, so the grid is now interpreted
metrically afterwards: a systematic strong/weak alternation means the
real beat is every other grid point.
- Beat grid drifted ~30ms over 30s from integer-frame offsets. Onset peaks
are now parabolically interpolated and the grid least-squares fitted.
Gates: 11/11 node tests against synthetic ground truth (tempo within 2%
across 90-174 BPM, beat alignment under half a frame, segmentation within
2s of a known boundary, graceful on silence, 6-minute analysis in 1.0s);
5/5 browser checks including audio-driven vs fixed-step frame parity.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
