source-media-signals

name	source-media-signals
description	Collect first-pass source media facts, audio silence/energy, shot estimates, representative frame status, and persistent text/caption risk evidence.

Source Media Signals

Use this when an agent needs conservative source-video signals before deeper review. This skill is intended as an intake layer, not a semantic video understanding pass.

This skill owns:

• ffprobe facts through the existing media probe
• audio energy and silence signals through ffmpeg when available
• coarse shot and scene estimates through video-shots when possible
• representative frame evidence status
• persistent text/caption risk evidence from nearby OCR/layout artifacts when present
• deterministic frame/video fallback evidence when OCR/layout artifacts are absent

Inputs

Required:

{
  "videoPath": "./output/example-run/output.mp4"
}

Optional fields:

• outputDir: directory for source-media.signals.json; defaults next to the video.
• outputPath: exact JSON output path.
• sceneThreshold: ffmpeg scene-change threshold, default 0.08.
• minShotDurationSeconds: minimum shot duration, default 0.5.
• extractRepresentativeFrames: whether to write video-shots/shot-*.jpg, default true.
• runAudioSignals: whether to run ffmpeg audio analysis, default true.
• runVideoShots: whether to run shot analysis, default true.
• silenceNoiseDb: silence threshold, default -35.
• silenceMinDurationSeconds: minimum silence duration, default 0.25.

Outputs

The result contains manifestPath and manifest. The manifest is source-media-signals.v1 and writes:

• ffprobe.status and normalized media facts
• audio.status, volume fields, and silence segments
• video.status, shot counts, boundaries, and scene-estimate metadata
• representativeFrames.status and frame paths when available
• textRisk.status, riskLevel, metrics, artifact paths, and bounded evidence items for visible source text, caption/bottom text, layout text issues, or deterministic frame/video fallback signals.

Interpretation Notes

Evidence status is part of the output contract. Treat unavailable, failed, and skipped as abstention signals, not as proof that a risk is absent. When OCR/layout artifacts are unavailable, textRisk.evidence still records fallback frame/video signals so downstream guards can persist why the text risk decision was conservative.

Repo-side runner:

node --import tsx scripts/harness/source-media-signals.ts

Installed-pack runner:

node ./.video-evaluator/agent/run-tool.mjs source-media-signals