# AI Film > Produce multi-shot narrative short films (60–240s) with AI video generation — story architecture, shot design, locking a real person's face across dozens of shots, dialogue, transitions, black-and-white and period looks, subtitles timed from audio, and multi-language/multi-ending variants. Use when asked to make a short film, movie, remake, cinematic video, trailer, or any multi-scene narrative video with recurring characters. Also use when an existing AI video looks "not cinematic", when a viewer says they can't follow the story, when characters drift or get swapped between shots, when someone's face stops looking like them, when props or wardrobe change between scenes, when a transition swallows a line, when "black and white" comes back in colour, or when a finished video won't play in a browser. - Skill: `kewang0622/ai-film` (Agent Skill, multi-file: 15 files) - Install (CLI): `npx skillmds@latest add kewang0622/ai-film` - Raw SKILL.md: https://api.skillmd.com/api/skills/kewang0622/ai-film/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: kewang0622 (https://skillmd.com/u/kewang0622) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/kewang0622/ai-film --- # AI Film Production Build a narrative short from a premise. Two stages: **generation** (paid, slow) and **post-production** (free, fast, endlessly re-runnable). Keeping them in separate scripts is the most important structural decision here — transitions, grading, loudness, subtitles and delivery get re-run dozens of times without spending again. ``` shots_.py scenes: shot design, identity, props, audio rules, dialogue check_script.py lints the script; --script prints the dialogue alone free generate.py → out_/*.mp4 via pika_client.py (stdlib only) paid audit_faces.py → audit_/*.png face contact sheets free finish.py → concat → grade → (subtitles) → (score) → cut free verify_film.py measures the cut: runtime, colour, music leak, banding free deliver.py → MASTER / full / share, two-pass linear loudness free ``` Copy `templates/` into a working directory, then `cp shots_template.py shots_.py` and edit that. Every other script is generic and routes by `--project `. Run `check_script.py` before spending anything. --- ## The one rule everything else follows from **The model executes descriptions. It does not execute negations. And it fills every space you leave it.** Nine times out of ten a defect is fixed by *changing what you described*, not by adding another "NO …". Measured, repeatedly: | Defect | Adding a negative | Changing the description | |---|---|---| | Extras appearing on a small boat | failed twice — "NO other passengers, NO crowd, NO boatman" | fixed first try — "shoot the whole boat bow to stern so the people can be counted" | | A santa hat from the reference photo | failed | fixed — supply a **clean reference photo** | | Calligraphy laid out wrong | failed twice | fixed — describe the physical sheet, not the forbidden layout | | Two characters swapped for the whole film | n/a | fixed — remove the body-type adjectives that were fighting the photos | | A second pistol appeared in a stand-off | n/a | fixed — "EXACTLY ONE revolver, the one in her two hands" instead of placing it "low in the corner of frame" | | A destroyed room came back barely scuffed | "comprehensively destroyed" | better — "the room is ALREADY a wreck in the first frame" | Negatives still earn their place for *iconography* ("no opera makeup", "no fur on the face") — they suppress a strong prior. They are near-useless for composition, staging and headcount. --- ## Order of work 1. **Story first.** Premise → 8–19 scenes, four acts, uneven durations. Pick the recurring object and the spoken promise, and **write the causal chain as a list of facts** before any shot design. → `references/story.md` 2. **Check the subject for identity risk** (see below). This decides how much of your budget goes to reruns. 3. **Reference photos.** Real photos, clean background, face large. Two per person at different angles is best; one clean frontal photo can hold. → `references/identity.md` 4. **Write `shots_*.py`.** Six design elements per shot; dialogue carries all plot. → `references/prompting.md` 5. **Audit it as a stranger.** `check_script.py --script` prints only what the audience hears. Read it top to bottom as someone who has never heard of the film. 6. **Generate ONE shot with each new face and look at it — cropped, front-on.** A profile test frame cannot verify anything. 7. **Generate the rest**, then iterate freely in post. 8. **Verify by measurement, not by glance.** Face crops beside the reference; `verify_film.py` for everything else. Exit code 0 means nothing here. --- ## Choose the subject knowing what it costs **Subject choice is the single largest driver of identity cost.** A character with a famous "standard face" will overwrite the actor's face, and no amount of prompt work fully removes it. | Subject | Result | |---|---| | Idiom fables, original stories, generic-period drama | **12/12 first pass**, zero identity reruns | | *Dream of the Red Chamber* — famous but no face paint | 13/13 first pass | | *Mulan* — famous but no fixed face | 11/13, 2 unrelated failures | | A 1942 Hollywood romance remade with two leads in their seventies | 2 of 17 first-pass shots rerun for face drift (small face; a prop holding focus); every later rerun was story, staging or wardrobe | | *Journey to the West* — Monkey King | **3 full rounds of reruns** | | *Three Kingdoms* — Guan Yu's red face and beard | **8 of 12 shots reshot** | If the brief demands a high-prior character, budget the reruns up front and say so. Then strip the entire iconography — not just the name. → `references/identity.md` --- ## Non-negotiable rules Each of these cost a generation cycle to learn. 1. **Write shot design, not scene description.** LENS, FOREGROUND, FRAME, BLOCKING, EYELINE, MOVE. Without them: subject-centred, symmetrical, facing camera — a stock photo. Camera-body jargon buys texture, not cinema. 2. **The photograph wins.** Never write a physical attribute that contradicts the reference photo. Body-type adjectives override the `@ImageN` tag and the model will silently **swap two characters for an entire film**. 3. **Never age a face.** No de-aging, no aging-up, no child/teen variants. The era is carried by wardrobe, props, hair and set. A flashback to the leads' youth is shot **without faces** — hands, objects, weather — rather than de-aged. 4. **Lock identity with hardware that exists in the photo.** Glasses *shape* (square vs round vs oval) is the most reliable discriminator found. Build, height and face shape are not — they fool you in profile and in low light. 5. **A recurring prop needs a fixed description block, exactly like a character.** "A small notebook" yields a different notebook every scene and the object's three-beat silently breaks. 6. **Three simultaneous demands per shot, maximum.** Ask for five and the model does the cheapest one. 7. **Never let the video model score the film.** It composes music, the music trips copyright moderation, and the job fails *after* rendering — you pay, you get nothing. Ban it in every prompt; score in post, if at all. 8. **Title and end cards must be declared `ABSOLUTELY SILENT`.** With no dialogue the model invents ambience or music and trips the same copyright filter. 9. **Max three speakers and five lines per shot.** Beyond that the model loses the turn-taking and has two characters say the same line in unison. Add an explicit one-speaker-per-line rule to the global audio block. 10. **Adding to a prompt weakens what is already in it.** A long new prop block let Christmas wardrobe back in; a focal-plane block added to a stand-off dropped both leads' costumes. After lengthening a prompt, re-verify what previously passed, and restate wardrobe inside the shot as continuity. 11. **`provider_timeout` is not a content problem.** A ~20-minute server ceiling, driven by queue load, not shot complexity. It bills nothing. Retry unchanged. 12. **Never use a negative for headcount or framing.** Define the frame so the wrong answer has nowhere to live — and that applies to props: place a weapon by whose hands hold it, never by its position in frame. 13. **One generation is one image.** A drift across four subjects ("a series of tight framings… up the sleeve… out to the platform") came back as a dark blur, twice, in two films. Rewrite as one sustained image with one move. 14. **Transitions are picture-only.** A dip to black fades the image; sound carries straight through. A line was measured starting at 0.00s of the shot after a dip; in a controlled test the old 0.35s audio fade took 17 dB off its first syllable. --- ## A first-time viewer is the only audience that matters A remake passed every check — faces, colour, sync, lint — and still lost its audience. "If I'm watching this for the first time I don't know what's going on." Every break was missing **spoken** information: | Break | Fix | |---|---| | A flashback's city was first named **five shots after** the flashback | name it in the scene that leads into it | | The heroine's name was **never spoken** in 3.5 minutes; the hero's, four times | name every lead aloud, early | | The rule of the world (no one leaves without papers) was never stated | say it — it is why the whole plot matters | | The ending moved **three people on two travel permits** | count the resource out loud at the climax; plant the exception in the first half | | A time jump (night to dawn, one city to another) happened on a hard cut | dip to black at every jump in time or place | The method, all free: ``` 1. List the facts a stranger needs, each with the line that says it: CAUSAL_CHAIN = [("nobody leaves without papers", "nobody leaves this city"), …] check_script.py errors on any fact nobody speaks. 2. check_script.py --script → read only the dialogue, top to bottom, as a stranger. 3. Count every countable thing: tickets, seats, doses, bullets, letters. Viewers do this arithmetic whether you meant them to or not. ``` **When a viewer says they are confused, it is a script defect, not a taste note.** Do not re-grade or re-time it; find the fact nobody said. → `references/story.md` --- ## Verification is a procedure, not a glance Three separate defects shipped past a "verified" wide frame — a soft out-of-focus face, a face that had drifted to a stranger, and **two leads swapped for the entire film**. All three were found by the user, not by the check. ``` For every shot with a face: 1. Crop the face region and scale it up 2. Put it beside the reference photograph 3. Judge by glasses shape / hardware — not by face shape 4. Confirm WHICH person is wearing WHICH costume ``` `audit_faces.py` does the contact sheets. Look at **three frames per shot** (15%, 50%, 85%), never one: a single mid-frame once read as "side by side" for a shot that was correctly back to back, and "no fight" for a shot where the table went over. Then measure the cut — `verify_film.py`: | Check | How | What it has caught | |---|---|---| | Runtime | cut vs sum of **real** clip durations | concat truncation that exits 0 | | Colour | 95th-percentile chroma, never the mean | "black and white" shots in full colour; the mean hid them | | Music | spectral concentration per clip | a model-composed score under a music ban | | Banding | flat runs on gradients, skipping black frames | a false 1,663 px "band" that was a dip to black | | Wardrobe | mean brightness of a costume region per shot | a white dinner jacket that went dark (15 vs 128) | **A measurement that cannot be computed is a failure, not a pass.** A probe once returned −1 for every clip because its parser matched nothing, and the table read like a clean bill of health. --- ## Subtitles: time them from the audio Generated dialogue often sits at −37 dBFS under ambience. Fed raw to a transcription model it returns timings 10+ seconds out. ``` 1. Normalise hard first highpass + compand + loudnorm ← this is the fix 2. ElevenLabs Scribe, word-level timestamps USD 0.004/min 3. Align script lines to word timings sequentially (script order is authoritative) 4. Never sort cues by timestamp — it reorders dialogue ``` **Tokenise by language.** Scribe returns per-character tokens for Chinese and per-word tokens for English; comparing letters to words matches nothing and yields an empty subtitle file with no error. → `references/postproduction.md` --- ## Look, sound and delivery - **Black and white is demanded in the prompt AND forced in post** (`MONOCHROME = True`): panchromatic channel mix plus a silver-gelatin curve, not `hue=s=0`. - **Grain goes on in post** (`GRAIN = 5`), uniform across every cut, and every grainy master encodes with **`-tune grain`** — otherwise x264 smooths the grain and the banding it hid comes back. - **Loudness is two-pass linear.** Single-pass `loudnorm` is a compressor: measured, it lifted a silent title card from −65 to −16 dBFS and collapsed a 36 dB gap to 4 dB in a controlled test (on a real film: title at −17 dBFS single-pass, −42 linear). `deliver.py` measures, then applies one constant gain. - **Default to no score for dialogue-driven shorts** (`SCORE = False`). A viewer rejected a sidechain-ducked orchestral bed as competing with the lines, even with speech holding 70–80% of the spectrum. Ask before scoring. - **`-movflags +faststart` or the video looks broken** in a browser. Remux, don't re-encode. - **Three tiers**: MASTER (video stream-copied, first generation), full-resolution CRF 19 for watching, and a 720p share copy stepped down to fit a size cap. Chat and upload tools cap attachments (25–50 MB is common), so size the share tier to the channel. Never upscale. - **Name cards must be opt-in.** A fallback that returned a default set burned one film's character names into two unrelated films. → `references/delivery.md` --- ## Setup and access `PIKA_API_KEY` in the environment or a `.env.local` beside the scripts (chmod 600, never committed). Endpoints and field names come from the published index at `https://dev.pika.art/llms.txt` — read the linked per-model spec rather than guessing; the aspect field is `ratio`, not `aspect_ratio`. When nothing renders, the status says why, and the three look alike from a distance: | Response | Meaning | |---|---| | `401` | key unknown or malformed | | `403 "Your API key is not active"` | key exists but was deactivated | | `caller_plan_required` | key works; the plan does not include that model | | `422` | payload rejected — often a prompt over 15,000 characters | An `ImportError` in the wrapper script hides all four. One pipeline died importing a client library that had been deleted, which masked both a deactivated key and a plan that no longer included video models — two separate problems behind one traceback. --- ## Cost Read spend from job billing records, never from list prices — a naive estimate once read 4× high. | Operation | Measured | |---|---| | `seedance-2.5` reference- or text-to-video, 1080p, 4:3 and 21:9 | **USD 0.46/s** (0.457–0.460 across 60+ renders) | | `seedance-2.0-fast/reference-to-video` | ~USD 0.83/shot | | `minimax/minimax-music-3.0` (`is_instrumental: true`) | USD 0.09/call; ~105–170 s, no duration control | | `eleven-scribe/transcription` | USD 0.004/min | A 200-second film is ~USD 92 before reruns. Iteration on two remakes added 24% and 133% — the second because the story was rewritten twice after a viewing. Budget at least one full second pass. Concurrency is capped at 20 jobs in flight — exceeding it returns 429 on *uploads* too. `bytedance/seed-audio-1.0/text-to-audio` is a TTS model; instrumental prompts are rejected by its speech safety audit. Model discovery: `GET /catalog/apis`. --- ## Variants are cheap - **Alternate ending** — override only the shots that change. 3 of 11 ≈ USD 16. - **Another language** — reuse every shot design (already in English), swap only `dialogue` and the casting names. - **Re-grade, re-time, re-mix, re-deliver** — free. --- ## Working practice - **Do not invent constraints the user did not set.** Three rounds were burned forcing horizontal calligraphy to "match the previous film" when vertical is the correct convention and the real defect was a petal covering a character. - **When a complaint is directional, confirm the direction.** "There are several people on the boat" was a bug report; it was read as a request. - **Show a test before committing a batch.** Any new face: one render, cropped, front-on, approved, then spend. - **Gate every render on the patch having landed.** A prompt patch aborted on a failed assertion, wrote nothing, and three shots were rendered — and paid for — without the fix. Grep the built prompt for the new text before submitting. - **Keep rejected takes.** Move them aside rather than overwriting; the old take is the evidence for why the prompt changed. `generate.py` skips clips that exist. - **Never write a shell wait-loop that greps for your own command.** `pgrep -f "generate.py"` matches the wrapper shell running the loop, so it waits forever. Use your harness's background mechanism instead. - **Lint before you spend.** `check_script.py` catches the music ban, the 15,000-char prompt cap, casting on empty plates, missing shot-design elements, montages inside one generation, weapons without a headcount, and unspoken causal facts. - **No dollar-sign figures in this file.** When the skill is invoked with arguments, a dollar sign followed by a digit is treated as a positional placeholder and replaced by a word of the user's request — every price here once rendered as the name of the film being made. Write `USD 0.45`. --- ## Rights - **Do not use a real public figure's likeness** as a reference image. Generate an original character instead. Real private people from photos they supplied are fine — say once that you are assuming consent for the photos you were given. - Genre premises, historical events and plot *ideas* are not protected; titles and short phrases are not copyrightable. **Extended dialogue and specific written scenes are.** A remake keeps the beats and the iconography, quotes at most a famous short line or two, and writes every other line fresh. Treat public distribution of a close remake with more care than a private one. - **Not-showing is a craft tool, not just a constraint.** An antagonist as a gloved hand, a husband as a hand on a shoulder and a hat on a chair, a therapist as a voice behind the lens — each is stronger than showing the face, and each is one fewer likeness to hold. - Do not dramatise live litigation or unproven allegations about named real people. Swapping the faces does not change what the text is about. --- ## References - `references/identity.md` — **read this first**; faces, references, priors, swaps - `references/story.md` — object, promise, rhyme, the stranger audit, endings - `references/prompting.md` — prompt anatomy, copy-ready blocks, failure catalogue - `references/postproduction.md` — transitions, grading, loudness, subtitles, ffmpeg traps - `references/delivery.md` — tiers, encoding, hosting, faststart - `templates/` — `shots_template.py`, `check_script.py`, `pika_client.py`, `generate.py`, `audit_faces.py`, `finish.py`, `verify_film.py`, `deliver.py` - `examples/last-run/` — a complete 7-shot worked example