ugc-fixloop

The UGC fix-loop toolkit. The one-shot UGC video recipes (create-ugc-*-video-from-refs) render a single continuous Seedance 2.0 reference-to-video master with native lip-synced audio. This capability ships the two scripts those recipes run, so they exist on the remote machine (fetched into /tmp/gooseworks-scripts/ugc-fixloop/).

Any re-render of a replacement clip goes through the same proxy path the recipe uses for the take (create-video-fal / fal-proxy), NEVER a direct fal.run call.

Env / deps

• stitch_replacement.py — no API key, no network. Needs ffmpeg + ffprobe on PATH (all local FFmpeg).
• vet_seedance_prompt.py — routes through the GooseWorks openai-proxy (<api_base>/api/internal/openai-proxy/v1/chat/completions), reading creds from ~/.gooseworks/credentials.json — no direct OpenAI call, no local key; the call bills the Ads agent. Exits 3 if the proxy/creds are unavailable so the recipe can fall back to an inline self-review (the vet is advisory, not a gate).

Run — vet_seedance_prompt.py (GPT cross-model prompt review)

A deliberately NON-Claude second opinion on the Seedance prompt before you spend the render (Claude reviewing its own prompt is a weaker signal). Takes the prompt as an argument:

vet_seedance_prompt.py --prompt-file working/seedance-prompt.txt \
    [--brief "one-line intent"] [--refs "@Image1=avatar; @Image2=product; @Image3=env"] \
    [--words 28] [--out working/seedance-review.md]

Prints + saves the structured review (verdict, line edits, word budget, consistency risk).

Run — stitch_replacement.py (surgical beat/window swap, deterministic)

Replaces one segment of the master on the VIDEO track only; the master's audio (VO + ambience) plays straight through, so lip-sync on talking beats is never touched. Output is re-encoded H.264 / yuv420p at the master's fps + resolution.

Required: --master M.mp4 --replacement R.mp4 --output O.mp4. Pick the window ONE of two ways:

# By beat (1-indexed segment between auto-detected scene cuts):
stitch_replacement.py --master M.mp4 --replacement R.mp4 --output O.mp4 --replace-beat 2
 
# By explicit window (seconds):
stitch_replacement.py --master M.mp4 --replacement R.mp4 --output O.mp4 \
    --window-start 4.21 --window-end 8.75 --fit stretch

All args:

• --master (required) — the single-take master mp4.
• --replacement (required) — the re-rendered silent replacement clip (generated via create-video-fal).
• --output (required) — output mp4 path.
• --window-start / --window-end (float seconds) — explicit hole to replace.
• --replace-beat (int, 1-indexed) — pick the segment between detected scene cuts.
• --scene-threshold (float, default 0.3) — scene-cut sensitivity for --replace-beat.
• --fit {stretch,trim,freeze} (default stretch) — reconcile replacement length to the hole.
• --dry-run — print the ffmpeg command without running.

Warns if output duration drifts >0.15s from the master (audio-sync check).