| name | analyze-video-evidence |
| description | Analyze a local or downloaded video through timestamped human/automatic captions, ASR fallback, uniform and targeted ffmpeg frames, contact sheets, sanitized metadata, and a claim-evidence ledger. Use when Codex must summarize, compare, fact-check, extract rankings or recommendations, interpret slides/gameplay/demos, or create a Markdown/HTML report from Bilibili, YouTube, or local video while keeping conclusions traceable to exact speech and visual evidence. |
Analyze Video Evidence
Turn a video into a reviewable evidence bundle, then answer the user's actual
question from that bundle. Prefer source-backed findings over an untraceable
generic summary.
Inputs
Accept either:
- a local video plus optional SRT/VTT and yt-dlp
.info.json; or
- a Bilibili/YouTube URL downloaded first with
$download-web-video.
Require ffmpeg and ffprobe. Keep downloaded media, full transcripts, and
frames local unless the user authorizes publication.
Prepare the first-pass evidence
Run:
python3 <skill-dir>/scripts/prepare_evidence.py \
"./video-source/BV....mp4" \
--output-dir "./video-evidence" \
--subtitles "./video-source/BV....zh.srt" \
--info-json "./video-source/BV....info.json" \
--frame-count 24
If captions are omitted, the script prefers a nearby human Chinese caption,
then automatic Chinese, English, and other SRT/VTT files. Do not claim that
speech was analyzed when no captions exist.
When captions are absent:
- Extract/transcribe audio with an available local or user-approved ASR route,
such as the AX
$transcribe skill.
- Save SRT or VTT beside the video.
- Rerun the evidence preparation command with
--subtitles.
Inspect before concluding
Read transcript.md, evidence-index.md, and evidence.json. View
contact-sheet.jpg, then open ambiguous individual frames at full resolution.
The first pass samples the complete timeline rather than only transcript-picked
moments.
Identify topic transitions, enumerated items, tables, slides, on-screen labels,
and places where the creator revises or qualifies an earlier point. Add exact
frames for those moments:
python3 <skill-dir>/scripts/prepare_evidence.py VIDEO \
--output-dir "./video-evidence" \
--subtitles CAPTIONS \
--timestamp 00:08:42 \
--timestamp 00:19:15
Read references/analysis-method.md when the
task involves rankings, recommendations, factual verification, conflicting
captions, or a publishable report.
Build the claim-evidence ledger
Before writing, map each material finding to:
- a transcript time range and short paraphrase;
- a frame path when the claim depends on visible content;
- confidence (
high, medium, or low);
- a caveat when the source is context-dependent or ambiguous.
Distinguish the creator's explicit statement from your inference. Never invent
card names, slide text, numbers, or tiers to fill a gap.
Produce the requested artifact
Match the user's requested format. For a table or HTML guide:
- lead with the decision-useful result;
- make tiers or priorities scannable;
- preserve conditions such as act, archetype, existing synergies, or upgrade
state instead of forcing a universal order;
- attach compact timestamps to every important recommendation;
- include a methodology/source note and uncertainty labels;
- do not embed the full transcript or redistribute a large frame collection.
Use the frontend design workflow for a polished HTML artifact and visually
verify responsive layout with browser screenshots.
Acceptance criteria
Require all applicable conditions:
evidence.json, evidence-index.md, transcript.json, and transcript.md
exist.- The evidence manifest records media metadata, source SHA-256, caption hash,
cue count, frame timestamps, and nearby caption context.
- A full-timeline contact sheet exists when frames were requested.
- Consequential claims have timestamped speech or visual evidence.
- Inference and source statements are labeled separately.
- The final artifact answers the requested question, opens locally, remains
readable on desktop and mobile, and contains no cookies or signed media URLs.
Output bundle
<evidence-dir>/
├── evidence.json
├── evidence-index.md
├── transcript.json
├── transcript.md
├── contact-sheet.jpg
└── frames/
├── uniform_...
└── targeted_...
