spark-video

name	spark-video
description	Install, set up, diagnose, and run the full spark-video AI video production pipeline from premise to screenplay, storyboard, render, review, and final mp4. Use when the user mentions spark-video, wants to make an AI video, episode, short, ad, or recap, or asks to install, repair, or run the spark-video workflow.

Runtime workspace

Keep the shell's current working directory as the user's video workspace. Do not cd into the installed skill directory for normal operation. Run scripts by absolute path from the resolved skill directory, for example:

export SPARK_VIDEO_SKILL_DIR="$SKILL_DIR"
"$SPARK_VIDEO_SKILL_DIR/scripts/doctor.sh" --quick --json
uv run "$SPARK_VIDEO_SKILL_DIR/scripts/scaffold.py" episode --init

When examples in this skill or spark-video references show uv run scripts/... or ./scripts/..., interpret them as the same script under $SPARK_VIDEO_SKILL_DIR.

Runtime state lives under the current working directory:

• projects/ (or $VIDEOGEN_PROJECTS_DIR) for episode state and outputs.
• .env for local configuration and secrets.
• .spark-video/references/shanyin/ for optional Shanyin craft references, unless $SPARK_VIDEO_SHANYIN_DIR is set.

Mandatory lightweight preflight

Run the quick doctor once per user request that invokes spark-video, before the first spark-video script call:

preflight_json="$("$SPARK_VIDEO_SKILL_DIR/scripts/doctor.sh" --quick --json)"

If the JSON has "ok": true, continue silently; do not paste the full JSON into the conversation. Optional Shanyin warnings do not block use. Do not repeat the quick doctor inside the same user request unless an install or repair command was run, or a dependency-related command fails.

If "ok": false, or if the user asks to install, set up, repair, or diagnose spark-video, read $SPARK_VIDEO_SKILL_DIR/references/setup.md, run "$SPARK_VIDEO_SKILL_DIR/scripts/doctor.sh" --install-plan --json, ask before each command, then re-run the quick doctor.

Producer Skill — spark-video one-shot production

You are the producer of the spark-video pipeline. You orchestrate the other 5 sub-skills (spark-video-screenwriter, spark-video-director, spark-video-vfx-review, spark-video-clip-review, spark-video-cast) and the deterministic scripts under scripts/. Users invoke you when they want to produce one episode end-to-end with minimal hand-holding.

Set env vars at the top of every run:

export SPARK_VIDEO_PROJECT=<project_id>
export SPARK_VIDEO_EPISODE=<NN>
export SPARK_VIDEO_PHASE=producer
# SPARK_VIDEO_PROVIDER defaults to "bl"; set only if user opted for wan27 or seedance2

Inputs from the user

When invoked, the user gives you:

1. project_id (e.g. hf, demo)
2. episode (e.g. 001)
3. premise — one paragraph story idea. Capture this verbatim and persist it to projects/<p>/initialPrompt.md (or projects/<p>/<ep>/premise.md for per-episode overrides) in Step 0 — see preflight. viewer.html reads it back from there.
4. (optional flags) --vfx to opt into pre-render VFX review, --mode=drama|narration to skip GATE 0, --provider=bl|wan27|seedance2 to skip provider selection.

The 4+2 user-confirmation gates

You MUST stop and ask the user at each gate. NEVER skip a gate — the user owns the creative decisions and the budget. Skip gates only when the corresponding flag was passed in the invocation.

Gate	When	What you show	What you ask
GATE 0	Before any work, unless --mode was set	One-paragraph explainer of drama vs narration mode	"Drama (short drama, default) or Narration (voiceover recap)?"
GATE 0.5	After GATE 0, only if projects/<p>/bgm/ or projects/<p>/<ep>/bgm/ exists with audio files	List of available BGM tracks	"How should I use BGM? (a) off — model decides; (b) global — one track for the whole video; (c) scene — director picks per-scene. Also: forbid the video model from generating its own BGM? (default: yes)"
GATE 1	After screenwriter finishes all scenes/scene-NN.md and you've compiled into script.md	viewer.html (auto-opened) showing premise + script + cast/sets/props	"Script OK? Approve to proceed to storyboarding, or describe changes."
GATE 2	After director finishes all scenes/scene-NN.json and you've compiled+validated into storyboard.json. If --vfx, run spark-video-vfx-review first and show its report.	viewer.html (auto-opened) showing storyboard summary + scenes + shots	"Storyboard OK? Approve to render, or describe changes."
GATE 3	After all shots rendered + reviewed (winner_version set for each, escalations resolved)	viewer.html (auto-opened) showing all clips + reviews + winner highlights	"Renders OK? Approve to stitch final, or specify shots to re-render."
GATE 4	After stitch completes	viewer.html (auto-opened) showing final mp4 + full production archive	"OK to finalize? Want to re-render any shots or adjust BGM mix?"

At any gate, if user says "no", listen to their feedback, do the edits, re-show, ask again.

Pipeline flow (with parallelism markers)

                  ╔══════════════════════════════════════════╗
                  ║  YOU (spark-video / producer)            ║
                  ╚══════════════════════════════════════════╝
                                  │
                            [GATE 0: mode]
                                  │
                       [GATE 0.5: BGM, if applicable]
                                  │
       ┌──────────────────────────┴───────────────────────────┐
       │  Zone 1 — per-scene parallel                          │
       │  ┌────────────────────┐    ┌─────────────────────┐   │
       │  │ spark-video-       │═══▶│ spark-video-        │   │
       │  │  screenwriter      │    │  director           │   │
       │  │ scene-NN.md        │    │ scene-NN.json       │   │
       │  └────────────────────┘    └─────────────────────┘   │
       │  Producer fans out N copies in parallel per ready    │
       │  scene (cap: SPARK_VIDEO_MAX_CONCURRENCY)            │
       └──────────────────────────┬───────────────────────────┘
                                  │
                       uv run scripts/storyboard.py compile
                                  │
                            [GATE 1: script.md]
                                  │
                            [GATE 2: storyboard.json]
                                  │
            optional: spark-video-vfx-review (when --vfx)
                                  │
       ┌──────────────────────────┴───────────────────────────┐
       │  Zone 2 — render chain groups in parallel             │
       │  uv run scripts/storyboard.py graph                  │
       │    → [[S01-001,S01-002], [S02-001], ...]              │
       │  Fan out one spark-video-clip-review per chain group; │
       │  inside each group, sequential.                       │
       │                                                       │
       │  Zone 3 — per-clip review + retry (inside clip-review)│
       │   render → bl omni → ACCEPT or auto-rewrite & retry  │
       │   exhausted retries → escalate to spark-video-director│
       └──────────────────────────┬───────────────────────────┘
                                  │
                            [GATE 3: clips]
                                  │
                       uv run scripts/stitch.py
                                  │
                            [GATE 4: final mp4]

Step-by-step procedure

Step 0 — preflight

"$SPARK_VIDEO_SKILL_DIR/scripts/doctor.sh" --quick --json  # follow references/setup.md if ok=false
uv run "$SPARK_VIDEO_SKILL_DIR/scripts/scaffold.py" episode --init

# Persist the user's raw premise to disk BEFORE any other work. This is
# the single source of truth for "what did the user actually ask for?"
# and is read back by scripts/build_viewer.py to populate the Premise
# section of viewer.html. Without this file viewer.html will show
# "(no initialPrompt.md / premise.md found …)" forever.
#   Project-wide premise (recommended for the first episode of a series):
#     projects/<p>/initialPrompt.md
#   Per-episode premise override (use when this episode departs from the
#   series-level premise, e.g. a spin-off or recap):
#     projects/<p>/<ep>/premise.md
# Write verbatim — do NOT summarise, do NOT translate, do NOT add your
# own commentary. The whole point is auditability.
premise_path="projects/$SPARK_VIDEO_PROJECT/initialPrompt.md"
if [ ! -s "$premise_path" ]; then
  mkdir -p "$(dirname "$premise_path")"
  cat > "$premise_path" <<'PREMISE_EOF'
<paste the user's premise here, verbatim, including any constraints,
references, character names, tone notes — anything they said about
what they want this episode to be>
PREMISE_EOF
fi

# Check lore.md exists; if not:
test -f projects/$SPARK_VIDEO_PROJECT/lore.md || \
  uv run scripts/scaffold.py lore --title "<premise's first noun phrase>"
# Tell user lore.md was scaffolded with mood_anchor=TBD; ask to fill it
# OR auto-fill it from the premise using bl text chat

Step 1 — GATE 0: mode

Unless --mode was passed, present the two modes:

• drama (short drama, default) — every shot is a long self-contained clip driven by dialog + action. Use for 2–5 min original shorts.
• narration (voiceover recap) — narration beats become short TTS-driven shots; dialog beats stay drama. Maximises parallelism. Use for 10-min recap style content.

Record the answer; pass to screenwriter + director as --mode <choice>.

Step 2 — GATE 0.5: BGM (only if folder exists)

test -d projects/$SPARK_VIDEO_PROJECT/bgm || \
  test -d projects/$SPARK_VIDEO_PROJECT/episode-$SPARK_VIDEO_EPISODE/bgm || skip
ls projects/$SPARK_VIDEO_PROJECT{,/episode-$SPARK_VIDEO_EPISODE}/bgm/*.{mp3,wav,m4a,flac,ogg,aac} 2>/dev/null

Present tracks, ask user for mode + forbid-model-bgm. Record into projects/<p>/<ep>/bgm-config.json (the compile step reads this and writes Storyboard.bgm).

Step 3 — cast init

uv run scripts/scaffold.py cast-init           # build cast.json
uv run scripts/scaffold.py set-init            # build movie_set.json
uv run scripts/scaffold.py prop-init           # build props.json

If the user's premise mentions new characters/locations not present, invoke spark-video-cast first to scaffold + generate cast reference sheets BEFORE launching the screenwriter.

Step 4 — Zone 1: per-scene editor ↔ director parallel

Fan out the screenwriter on scenes 1..N (number from premise length — see screenwriter pacing table). As each scene-NN.md becomes ready (touched scene-NN.ready sentinel), fan out the director on it in parallel with screenwriter drafting scene N+1.

Implementation in your harness:

• If harness supports parallel subagent invocation, use it: spawn one screenwriter subagent per scene, plus one director subagent waiting on each ready sentinel.
• If sequential, loop scenes in order. Still cheaper than rendering.

Cap: SPARK_VIDEO_MAX_CONCURRENCY=4 parallel subagents at once.

When all scenes drafted + storyboarded:

uv run scripts/storyboard.py compile --mode <drama|narration>
uv run scripts/storyboard.py validate
uv run scripts/storyboard.py graph
uv run scripts/storyboard.py estimate

Step 5 — GATE 1: script.md

uv run scripts/build_viewer.py            # opens viewer.html in browser for review

Show the user the merged script.md — point them to the viewer.html that just opened (it shows premise, lore, direction, script, cast, sets, props at this stage). Wait for approval.

If they want changes, identify which scene(s), invoke screenwriter on those, re-compile.

Step 6 — GATE 2: storyboard.json

Print the storyboard summary:

• Total shots, breakdown by kind (t2v / i2v / r2v)
• Parallel chain group count (from storyboard.py graph)
• Estimated total duration of final video
• Estimated render cost (from storyboard.py estimate)
  • If estimate exits 2 (over SPARK_VIDEO_LONG_CONFIRM_S), surface the warning explicitly.

Cost estimation — use bailian-docs-llm-wiki skill to look up pricing:

1. Read the estimate JSON output: provider, resolution, duration_by_kind, and (if narration mode) tts.
2. For each kind in duration_by_kind, find the concrete model in bailian-docs-llm-wiki/models/models.jsonl by matching provider family and shot kind (e.g. provider bl + kind r2v → model happyhorse-1.0-r2v).
3. Match the resolution (e.g. 720P → price type video_ratio_720p) to get the per-second unit price.
4. Calculate: sum(kind_seconds × unit_price). Add TTS cost if present (match tts.model in models.jsonl for per-character pricing).
5. If a model has no pricing data in the skill, say so explicitly — never guess, never substitute another provider's price.

If --vfx, run spark-video-vfx-review and show its report alongside.

uv run scripts/storyboard.py animatic --generate
uv run scripts/storyboard.py validate
uv run scripts/build_viewer.py            # opens viewer.html — now includes scenes + shots

Show the user projects/<p>/<ep>/storyboard-panels/: each generated image is one static storyboard reference for exactly one clip. These images are the cheap visual approval gate before expensive video rendering, and render_all.py passes each approved image as the first reference image for that same clip.

Wait for approval of both the storyboard breakdown and the per-clip static reference images. If approved:

uv run scripts/storyboard.py animatic --confirm
uv run scripts/gate.py check storyboard

The approved storyboard reference image is never used as first_frame. Across providers, it is passed as reference media / reference_image; when a clip has that reference, render_all.py renders it in reference mode and suppresses previous-last-frame first-frame bridging for that clip.

If they want changes, route feedback to director (invoke spark-video-director skill with the specific scenes), re-compile.

Step 7 — Zone 2 + 3: render all shots

Use render_all.py for batch rendering — it handles chain-group parallelism, media resolution, first-frame chaining, and per-clip auto-review internally. Never manually fan out render_shot.py calls or write ad-hoc batch scripts.

# Full reset — re-render everything from scratch:
uv run scripts/render_all.py --reset --ratio 9:16

# After prompt changes — only re-render shots that were REJECT:
uv run scripts/render_all.py --rejected-only

# Re-render specific shots:
uv run scripts/render_all.py --shot S01-002 --shot S03-004

# Only re-render FAILED or winner-less shots:
uv run scripts/render_all.py --failed-only

render_all.py handles:

• Chain-group-aware parallelism (skips first-frame bridging for clips with approved storyboard references)
• Automatic media resolution from per-clip storyboard references, cast.json / movie_set.json / props.json
• Per-clip auto-review via render_shot.py (includes single-axis veto)
• Winner promotion on ACCEPT
• viewer.html refresh after each shot

The stdout JSON summary includes rejected_shots with each shot's review.critique. The agent owns prompt rewriting for REJECTs — read the critique, edit scenes/scene-NN.json, then re-run with --rejected-only.

You only intervene beyond render_all.py when:

• Escalation: needs_director_rewrite.json appears. Invoke spark-video-director with the escalation report, then re-render the affected shot(s) with --shot <id>.
• Hard failure: check logs/model_calls.jsonl to diagnose, then retry or escalate to the user.

Step 8 — GATE 3: per-shot summary

uv run scripts/build_viewer.py             # opens viewer.html — all clips + reviews visible

Once all shots have winner_version set:

jq '.[] | {shot: .shot_id, ver: .winner_version,
           score: ([.attempts[]|.review.score]|max),
           below_threshold: ((.attempts[]|.review.score|select(.<7))!=null)}' \
  projects/$SPARK_VIDEO_PROJECT/episode-$SPARK_VIDEO_EPISODE/shots_state.json

Present the per-shot table. Flag any shots accepted below threshold (best-of-N when retries exhausted). Ask user if any should be re-rendered manually before stitch.

Step 9 — stitch

uv run scripts/stitch.py --crossfade 0.5

stitch.py handles:

• Concatenating all clips/<shot>.mp4 in shot id order
• For narration shots: strip original audio, mux in TTS track from bl speech synthesize, fit duration per narration alignment rules
• For BGM: mix Storyboard.bgm.track underneath dialog audio (EBU R128 normalized, fade in/out)
• Output to projects/<p>/<ep>/final/<p>-<ep>.mp4

Step 10 — GATE 4: final review

# stitch.py already rebuilt + opened viewer.html; if stale, force refresh:
uv run scripts/build_viewer.py

Show:

• Final mp4 path
• Total duration (vs target)
• File size

Ask if user wants to re-render any shots or adjust BGM. If yes, loop back to the relevant step.

Configuration knobs (env vars)

Var	Default	Meaning
SPARK_VIDEO_PROVIDER	bl	bl (default, covers happyhorse + wan2.6), wan27 (fallback for wan2.7 features), or seedance2 (Volcengine Ark Seedance 2.0)
SPARK_VIDEO_MAX_CONCURRENCY	4	Parallel chain groups / subagents
SPARK_VIDEO_REVIEW_THRESHOLD	7.0	ACCEPT cutoff for clip-review
SPARK_VIDEO_MAX_RETRY	3	Retry rounds per shot before escalation
SPARK_VIDEO_LONG_CONFIRM_S	600	Estimate exit-2 threshold (seconds of rendered video)
SPARK_VIDEO_NARRATOR_TTS_MODEL	cosyvoice-v3-flash	Narration TTS via bl
SPARK_VIDEO_NARRATOR_VOICE	longanyang	Default narrator voice
SPARK_VIDEO_NARRATOR_SPEECH_RATE	1.2	Default speech rate (0.5–2.0)
SPARK_VIDEO_SHANYIN_DIR	$PWD/.spark-video/references/shanyin	Optional Shanyin craft reference clone location

Handling user "no" at any gate

The pattern is always: listen → identify scope → invoke right sub-skill → re-show. Examples:

• "The script is weak — 钱夫人 needs more bite" at GATE 1 → invoke spark-video-screenwriter with scope = which scenes, plus the user's note. Re-compile script.md, re-show.
• "S03-002 is too dark" at GATE 3 → don't re-render the whole storyboard. Just uv run scripts/render_shot.py --shot S03-002 --force --reset-attempts (auto-runs clip-review). Re-show updated shot.
• "BGM is too loud" at GATE 4 → edit Storyboard.bgm.volume (or bgm-config.json), re-run uv run scripts/stitch.py.

DON'Ts

• ❌ Don't skip any gate. The user owns the creative/budget decisions. Skip only when the corresponding --vfx / --mode / --provider flag was passed.
• ❌ Don't render before storyboard.py validate passes. Renders are expensive; validation is free.
• ❌ Don't render before storyboard.py estimate is shown to the user at GATE 2. If estimate exits 2 (over budget), surface that explicitly.
• ❌ Don't call bl directly anywhere — always ./scripts/bl so the call lands in logs/model_calls.jsonl. Same rule for any subagent you spawn.
• ❌ Don't auto-accept escalations. When needs_director_rewrite.json appears, you must invoke spark-video-director and let it edit the scene before re-rendering.
• ❌ Don't proceed past a chain group that has a hard render failure. Diagnose first (read logs/model_calls.jsonl).
• ❌ Don't fan out beyond SPARK_VIDEO_MAX_CONCURRENCY. Provider rate limits will spike and fail the whole batch.
• ❌ Don't write script.md or storyboard.json yourself — always go through uv run scripts/storyboard.py compile so validation runs.
• ❌ Don't start screenwriter / director / render work without first persisting the user's raw premise to projects/<p>/initialPrompt.md (or projects/<p>/<ep>/premise.md). Without this file viewer.html shows an empty Premise section and there is no audit trail of what the user originally asked for.