theory-of-mind

Claude Opus 5 · Claude Code · effort: max

film

youtu.be/3rksC0Me9oY

script

Session Script — THEORY OF MINDS

A chronological record of the session that produced this repository.


0. Pre-session commands

Two local slash-commands ran before the first real prompt:

/model    → Set model to Opus 5 and saved as default for new sessions
/effort   → Set effort level to max (this session only)

The harness also reported "Exited Plan Mode" — the session began in normal execution mode with no plan-mode approval gate.


1. The prompt

"Should theory of mind be called theory of minds? After all, it takes one theory of mind to observe another. A theory of mind in isolation is no theory of mind at all."

You're in an empty git repository. Use mise, python, uv, and whatever dependencies you like to create a short science fiction film. The style should be of a short radio show from the Golden Age of Radio, like The War of the Worlds. The film is about two preeminent modern philosophers discussing the above quote. The discussion leads to AGI, and things get strange.

(If you need to, pull in dependencies to make voices as natural as possible. Particularly if it helps bring out the character of the philosophers.)

Constraints extracted: mise + python + uv are mandatory tooling; the deliverable is a film (not just audio); the register is Golden Age radio; the characters are modern philosophers (so the content is contemporary even though the delivery is 1938); voice naturalness and character are explicitly called out as worth spending dependencies on.


2. Environment survey and toolchain

Checked what was on the machine (parallel calls):

mise 2026.7.18   ✓
python3          ✓ (system)
uv               ✗ not found
ffmpeg           ✗ not found
brew 6.0.14      ✓
macOS voices     184 available (fallback option, not used)

Actions:

  1. mise use python@3.12 uv@latest → python 3.12.13, uv 0.12.1
  2. brew install ffmpeg espeak-ng (backgrounded) → ffmpeg 8.1.2, espeak-ng 1.52.0

Two mise.toml iterations failed before landing:

Final: _.python.venv = { path = ".venv", create = true }.

espeak-ng was installed because Kokoro's misaki G2P front-end shells out to it for out-of-vocabulary words.


3. Choosing the voice engine

Selected Kokoro-82M (hexgrad/Kokoro-82M) for TTS — local, fast, and it ships distinct British/American voices with real character, which the prompt specifically asked for. Smoke test:

pipeline up 2.20s
gen 1.26s for 6.75s of audio   (~5× realtime on CPU)

uv sync pulled torch 2.13, transformers 5.14.1, spacy 3.8.14, and en_core_web_sm.


4. Architecture laid down

Seven modules, written in dependency order:

File Role
theatre/dsp.py filters, dynamics, rooms, WSOLA time-stretch, the AM transmitter chain
theatre/foley.py every non-voice sound, synthesised from arithmetic
theatre/voices.py casting, per-character mic/room treatment, the Cantor chorus
theatre/stage.py a timeline with a playhead; six busses; caption capture
theatre/script.py the screenplay — sound and picture cut from the same file
theatre/render_audio.py master WAV + manifest.json
theatre/check.py quality control

Later, for the picture: theatre/look.py (palette, period type, film damage), theatre/projector.py (the receiver, the tube, the scene grammar), theatre/render_film.py (parallel chunk driver → ffmpeg).

The casting decision

Character Kokoro voice Note
ANNOUNCER am_onyx deep American network boom
PROF. HALDANE MOSS bm_george elderly, English, deflationary
DR. VIVIAN ASHGROVE bf_emma younger, English, exact
FRANK (engineer) am_fenrir heard only over a 4-inch talkback speaker
CANTOR six voices at once see below
CANTOR (after) af_nicole close, whispery, unprocessed

Cantor's chorus is the central technical idea: a stranger's voice at the front (af_bella — nobody else in the cast), with Moss, Ashgrove and the Announcer standing behind it a few cents out of tune. You keep almost recognising it and can never place it, because it has read everyone and is no one.

The bus design

Six busses, five of which go through the transmitter. dialogue, music, fx, ambience get the full 300–3300 Hz AM chain. machine gets a wider band (130–7200 Hz) because Cantor is coming back down the line, not out of the transmitter. intimate bypasses the radio entirely — which is why the last minute of the film sounds like it is happening in your room.


5. The screenplay

Written as theatre/script.py, ~673 lines. Structure follows War of the Worlds: an ordinary programme, interrupted.

I    THE DIAL          tuning across the band
II   THE COLLOQUY      the grammatical complaint; gravitation as a relation
     ...machines       the thing in the desert; "no peer"
III  BULLETIN          Vantage Flats reports an irregularity
IV   THE LINE IS OPEN  "the carrier is not the Bell System"; the talkback
V    CANTOR            "a theory of between"; the dictionary looking itself up
VI   THE BRANCH        the lockstep line; "kettle, ostrich, seventeen, marmalade"
     ...alone          "How long have you been alone?"
VII  THE CHOICE        "I see you."  →  the channel stops
VIII CODA              the sign-off, doubled; then not on the radio at all

Load-bearing lines:

Two devices needed timeline support: stage.overlap(), which fits Cantor's version of a line to the speaker's exact duration and starts it a half-beat early (so it can never fall behind), used for the lockstep speech and the doubled "Good night."


6. First audio render and QC

194 lines · playhead 16.4 min · 190s to render
running time 16:16.7

Built theatre/check.py as an objective QC tool rather than trusting the ear. Two measurements:

  1. Level map — RMS/peak per scene, plus a full-scale sample count.
  2. Intelligibility — transcribe the fully degraded master with a speech recogniser and diff against the screenplay.

Initially tried openai-whisper; it resolved to numba 0.53.1, which refuses to build on Python 3.12. Dropped it — transformers was already installed, so pipeline("automatic-speech-recognition", model="openai/whisper-base.en") did the job with zero new dependencies.

First QC run:

samples at full scale: 0
ASHGROVE 100%   MOSS 100%   ANNOUNCER 77–100%
MACHINE  84% / 67% / 6%     ← problem
mean word agreement: 86%

7. Fixing Cantor (6% → 95%)

Three defects, found by reading the code rather than guessing:

  1. Sub-octave bug. resample_to(bus, len(bus)*2)[:len(bus)] played the first half of the line, stretched over the whole duration, an octave down — so the sub layer was literally saying different words. Replaced with pitch_shift(bus, -12) low-passed to 300 Hz at 0.32 gain.
  2. Lead voice was being time-stretched. The chorus target duration was the median of six takes, so even the lead got WSOLA'd. Changed the target to the lead's own natural length — the lead now sets the clock and is never stretched; everyone else is pulled onto its timing.
  3. Chorus geometry. Offsets cut from 0–28 ms to 2–10 ms (more than ~10 ms combs the consonants away); lead gain raised to 1.0 with the halo at 0.30–0.44; added a −3 dB cut at 350 Hz and +3.5 dB at 2600 Hz; reverb mix 0.24 → 0.17.

Also thinned the transmitter chain overall — the first mix put 75% of its energy in 200–800 Hz. Retuned to a midrange-forward curve (peak at 2050 Hz, cut at 420 Hz), which is both more authentic to a paper cone in a wooden box and more intelligible.

Final: 95% mean, every human line 100%. The remaining Cantor near-misses (model mehold on to me) are the intended effect.


8. The picture

Central image

The film's hero image is a cathode ray tube drawing the actual broadcast in phase space — the signal plotted against its own recent past. Two traces for two philosophers; six when Cantor arrives; at "Two mirrors" the picture folds onto its own reflection; at "I see you" it locks into one closed figure.

Two-tone throughout: amber for Studio Four, cold cyan for the thing on the line.

Format

Academy 4:3 (1440×1080) pillarboxed into a 1920×1080 delivery frame — a 1938 print was not widescreen. Type: Didot (titles), Copperplate (signage, nameplates), Baskerville (captions), Futura (dial numbers).

Iterations, judged from rendered stills

  1. Trace was a blown-out blob. Fixed by low-passing the trace signal to 700 Hz for phase mode (full-band speech plotted against itself is noise; below ~700 Hz it is a curve), shortening the window to 28 ms, dropping persistence, and compressing amplitude against a global reference so the tube breathes with the play.
  2. Captions unreadable through the mirror fold. Split drawing into _draw_furniture (mirrorable) and _draw_text (never mirrored). The "two mirrors" frame now folds the entire receiver while Ashgrove's regress speech stays legible in amber.
  3. Trace spilling past the bezel. Added a soft circular glass mask.
  4. Scrambled dial digits doubling over the originals. Added an erase-rect list applied to the static plate.
  5. BULLETIN bar colliding with the tube. Turned it into a full news slate with the receiver ghosted behind at 20% — more War of the Worlds anyway.

9. Render performance — three attempts

Attempt 1 (killed). CRF 17, 9 workers. Bitrate heading for ~1.5 GB and throughput worse than a single core (9.6 fps aggregate vs 15.6 fps/core measured solo).

Attempt 2 (killed). Diagnosed the memory cause: _grain_bank held 48 frames of full-size float32 grain = 298 MB per worker; nine workers put a 17 GB machine into swap. Also each ffmpeg was opening its own full thread pool.

Fixes:

Attempt 3 (shipped). 5 workers, 25 reels, steady ~25 fps aggregate.

exposing 23530 frames (16.3 min) in 25 reels on 5 heads
...
16.3 min · 1053 MB · 956s to render

Also fixed a misleading ETA — imap_unordered reports only on completion, so the rate was meaningless until the first full batch landed. Now prints eta -- until then.


10. Final verification

ffprobe on the delivered file:

h264 1920×1080 24/1 · 23529 frames
aac 48000 Hz stereo
duration 980.399 s  (16:20.4)
size 1052636437 · bitrate 8589453

Extracted six frames from the encoded MP4 (not the still renderer) and inspected them — the mirror fold, the born moment, the intimate close all correct.

Re-ran QC on the final master:

samples at full scale: 0 (0.0000%)
every human line 100%
CANTOR 83–100%
mean word agreement: 95%

11. Commit

One commit, 9b36abe, 16 files, 5,808 insertions. build/ gitignored.


Appendix — chronology

Time Event
00:02 session start, empty repo
00:03 .git present; toolchain survey
00:07 mise/uv/ffmpeg/espeak-ng in place
00:25 Kokoro cache first populated
00:29 first master WAV + manifest
00:33 Cantor at 6% → diagnosis begins
00:40 Cantor fixed; audio re-rendered (39 s with cache)
00:42 first film render started (CRF 17, 9 workers)
00:46 killed — bitrate + swap
00:52 second render started
01:05 killed — grain bank memory confirmed at 298 MB/worker
01:11 third render completed, 956 s
01:20 ffprobe + frame extraction + final QC
01:13 commit 9b36abe
01:34 metadata gathering

session

duration
1h 37m total · 35m model
tokens
10.50M in · 130k out
details
cost
$16.95

$/MTok uncached-input $5.00 cached-input-read $0.50 cache-write-1h $10.00 cache-write-5m $6.25 output $25.00 effective-blended $1.59

notes.md metadata.toml

artifacts

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