taste-distillation

Taste Distillation

This standalone skill ships its implementation in scripts/; use

taste-application for the subsequent generated or local-take edit. Keep each

named genre in its own pack. Measurements from Flash Ethereal must not be

silently reused for Fluid Sketch or 3D Cyber Glitch. A measured zero is valid

data; distinguish it from an absent field.

Local dependencies are in scripts/requirements.txt. Separately authorized

provider work also needs scripts/requirements-live.txt, credentials and

explicit TASTE_FORGE_ALLOW_LIVE=1. --dry-run does not read credentials or

submit jobs. Never infer that a workflow was saved from a local endpoint name;

use the actual provider-side workflow or request evidence.

Turn reference videos into a style pack: a folder of measurements and assets

that later stages consume deterministically.

When to Activate

• "capture the look of these clips" / "distill the vibe" / "make this repeatable"
• User has reference footage and wants a LUT, a grade, or matching pacing
• Building a library of looks partitioned by genre
• Any request where the answer would otherwise be "describe the style in a prompt"

The Core Finding

Prompting cannot deliver a grade. Measurement can.

Measured on real footage: three paid generations with escalating colour direction

moved midtone a\* from +1.9 → +2.8 → +0.3 against a +24.9 target, and contrast

never left ~19 against a 34.7 target. Applying a measured pack to the same

footage hit chroma MAE 1.88 and contrast 33.7 in one deterministic pass,

for free.

So the split is: **the model supplies content, motion and lighting structure; the

pack supplies the look.** Colour words in a generation prompt are worse than

useless — they cost money and push the render away from the neutral base the LUT

wants. Say so explicitly in the prompt: *"Colour: none. Render neutral. Grading

is applied afterwards."*

What a Pack Contains

stylepacks/<genre>/
  grade.json      measured colour statistics (see below)
  cadence.json    every detected shot boundary + the derived distribution
  look.cube       33^3 LUT, drag straight into Resolve as a node LUT
  spec.json       VLM description, grounded in the measurements
  grounding.txt   the measured facts fed to the VLM
  stills/         full-res frames from the longest shots (conditioning images)
  plates/         screen-blend overlay elements lifted onto black
  props/          minted GLB meshes
  pack.json       manifest

Running It

python mint.py --genre <name> --refs a.mov b.mov c.mov     # offline, no API key
python distill.py --genre <name>                            # one VLM call

mint.py is pure numeric analysis — no network, no key, deterministic, so a pack

can be regenerated rather than backed up.

The Measurements That Matter

Chroma by luminance zone, not globally

Colour identity usually lives in one luminance band. A global a\/b\ offset

mathematically cannot represent split-toning. Measure chroma inside zones

(L* edges [0,15,35,55,75,100]).

A real signature: violet at L\25 (a\ +24.9, b\* −17.5), near-neutral at both

ends. Reporting only the darkest and lightest zones calls that "uniform cast" —

always print the whole curve.

Median + MAD, never mean + std

Chroma in real reference sets is strongly right-skewed. On one measured reel the

mean midtone chroma was 36.9 against a median of 17.5, so a mean-based LUT pushed

colour ~3x harder than the material warranted.

Contrast is std(L\*), not white minus black

The white−black range is ~100 on almost any real footage and discriminates

nothing.

Background share is a first-class statistic

Record the share of pixels below L\*10. No moment of the distribution can see it:

a clip can hold the right mean, std and chroma while its blacks have been lifted

into grey. This is exactly how a grade once scored MAE 1.88 / contrast 33.7 while

the actual frame was a muddy purple mess.

Mask the interface before measuring

Screen-recorded references carry static furniture — letterbox bars, a status bar,

a like icon, caption text. All of it lands in the statistics as if it were the

look: black bars inflate shadow weight, a red heart skews a\* toward magenta.

Temporal variance separates them cleanly — the footage moves, the interface

does not — so no hand-tuned crop is needed. On real material this keeps ~65% of

pixels.

Cadence needs an adaptive threshold

The right content-detector threshold is material-dependent: a high-contrast

action reference cuts hard enough for 30, a moody one hides its cuts under it.

Sweep descending thresholds and take the highest one that still recovers ≥90%

of the shots the most sensitive setting finds — that biases toward real cuts over

noise. Reject thresholds implying an absurd cut rate (>100/min); continuous

camera moves trip the detector every frame.

Run the whole sweep in one decode pass with a shared StatsManager. The

naive version re-decodes per threshold, which on 60fps source is the difference

between seconds and minutes.

Overlay Plates: Assets, Not Screenshots

A still is a whole frame — compositing one just puts a second picture on top.

A plate is the reference's graphic vocabulary (flares, streaks, glitch

fragments) lifted onto black so it screen-blends with no keying.

Two traps, both hit on real material:

1. Absolute thresholds fail. On a bright reference an L>55 AND chroma>12

selection takes ~90% of frame, and the "plate" is the picture — including a

recognisable face. Select by percentile (~top 3%) and **reject any plate

covering more than ~22% of frame.**

1. Rank by separation, not by brightness. "Share of bright saturated pixels"

ranks a washed-out frame top and a black frame with one intense flare — the

actual signature — near the bottom. Score p99.5(energy) / median(energy).

Also mask before scoring: burnt-in typography is bright, saturated and

high-contrast, so an unmasked run yields a perfect plate of someone else's title

card.

Grounding the VLM

Feed the measurements into the system prompt before asking for a description.

Ungrounded, a VLM will report "no apparent colour grading, neutral" on footage

with a +24.9 a\* cast. Grounded, it describes the cast correctly and infers the

secondary accent independently.

Ban hedging words (varied, mixed, dynamic, some, often, neutral,

or) — a model cannot render "varied lighting". **Enforce the ban in code, not

just in the prompt:** it was violated in roughly one run in three. Re-ask

per-field, keep the least-hedged answer after N attempts rather than failing.

Caveat worth stating to the user: once the spec is grounded in the measurements

it is no longer an independent check on them.

LUT Baking Gotchas

• A LUT can only encode a per-pixel RGB function. Anything

distribution-dependent (histogram matching, percentile anchors) must be reduced

to a constant before baking, or it silently measures the uniform LUT grid

instead of the footage.

• cv2.cvtColor(LAB2RGB) clamps internally, so an out-of-gamut test using it

reports 0%. Convert Lab→linear sRGB by hand; a real measurement was 83.3% OOG.

• Offset chroma transfer, not affine. Affine divides by the source σ and

overshoots — on real footage it flipped b\* to +11.6 against a −17.5 target.

Offset took MAE from 6.23 to 2.13.

• Gamut compression cost 3.8x runtime for identical MAE. Make it opt-in.

Anti-Patterns

| Don't | Why |

|---|---|

| Tune against synthetic test footage | Cost four separate wrong conclusions on one project; real footage overturned every one |

| Trust MAE alone | 1.88 MAE looked like success on a visibly broken frame |

| Use mean/std for chroma | Right-skewed; pushes ~3x too hard |

| Compare only endpoint zones | Both ends are near-neutral by construction |

| Describe the look and stop | The spec is for content and structure; the pack is for colour |

Handoff

The pack is the interface. Once it exists, use the taste-application skill to

generate and assemble against it, or hand look.cube to a colourist directly.

Bundled Code

scripts/ in this skill is a working implementation, not pseudocode. It has no

project-specific assumptions: point it at any reference videos and it produces a

pack.

pip install -r scripts/requirements.txt
export FAL_KEY=...            # only needed for the stages that call fal

Every network call is stubbed under TASTE_FORGE_DRY_RUN=1 or --dry-run, so

the plan, prompts, track layout and manifest can be inspected without spending.