switch-faces

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name: switch-faces description: Hard-cut to a non-speaking listener's reaction shot at speech pauses — the "react" cutaway a real editor inserts while the speaker breathes. Deterministic, no Claude: detects a second face in the 16:9 source (reusing fill-vertical's face/identity clustering), picks the biggest speech-pause beats, and crops that listener's face into 1080x1920 for a ~0.8-1.2s hold before returning to the speaker. Timeline-preserving (audio copied, duration identical) so downstream timestamps stay valid. Runs on the clean vertical AFTER zoom-punch and BEFORE broll/captions. Solo talking-heads (no second face) pass through untouched. SWITCH_FACES=0 disables. allowed-tools: Bash user-invocable: true

switch-faces

When two people share a frame (or a multicam podcast), a real editor cuts away to the listener reacting while the speaker talks — it manufactures "multi-cam" energy and breaks up a static two-shot. This skill does it deterministically: it finds the non-dominant face in the 16:9 source and hard-cuts to a 1080x1920 crop of it during the speaker's natural pauses.

It is the reaction-shot sibling of zoom-punch (re-zooms the speaker at loud words) and jump-cut (reframes the same speaker on a tiling rhythm). All three are deterministic, timeline-preserving lap passes on the clean vertical.

Invoke

.claude/skills/switch-faces/switch-faces.sh <base_vert.mp4> <source16x9.mp4> <transcript.json> <out.mp4>

• base_vert.mp4: the 1080x1920 vertical clip to composite onto (post zoom-punch)
• source16x9.mp4: the pre-vertical 16:9 source (clip_NN.tight.mp4 / the verify-bookends recut) — holds the listener's face, cropped out of the vertical
• transcript.json: the clip-local word-timed transcript (same timeline as the vertical — fill/jump/zoom are all timeline-preserving)

Placement rules

• needs ≥2 face identities in the source (dominant speaker + a listener); solo clips → passthrough
• listener = a non-dominant face per shot, the calmest (least lip motion) one — reads as listening, not a second speaker
• windows = the biggest inter-word pauses (SWITCH_MIN_PAUSE, default 0.32s), biggest first; window starts ~0.4s before the gap so the cut catches the speaker landing the line
• hold = ~0.8-1.2s (cycles 1.1/0.9/1.0/0.8), count = clamp(dur/12, 1, 4), ≥5s apart
• excludes the cold-open title region (first SWITCH_LEAD=2.8s) and last SWITCH_TAIL=1.5s
• a window must lie inside one shot with the listener present for its whole span — never straddles a shot cut
• listener framed a touch looser (SWITCH_FACE_FRAC=0.40) than fill-vertical's speaker (0.45)

Chain position

After zoom-punch, BEFORE broll-pick/broll-composite (b-roll cutaways may still override their own windows) and burn-subtitles (captions burn on top of the reaction shot). Timeline-preserving — audio is stream-copied and total duration is identical, so every downstream timestamp stays valid. Orchestrators treat it as non-fatal: on any failure the vertical passes through. Disable with SWITCH_FACES=0.

Output

1080x1920 mp4, video re-encoded, audio stream-copied. Idempotent via <out>.sfmeta. No listener / no pause windows → passthrough copy.