# Live Slice > Use when working on live video slicing, 直播切片, 剪直播, 智能切片, 听悟 transcription, or live video slicing workflows that turn long livestream videos into transcript-backed short-video clips. - Skill: `anbanai/live-slice` (Agent Skill) - Install (CLI): `npx skillmds@latest add anbanai/live-slice` - Raw SKILL.md: https://api.skillmd.com/api/skills/anbanai/live-slice/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: anbanai (https://skillmd.com/u/anbanai) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/anbanai/live-slice --- # 直播切片 Use this skill to convert a local livestream video into transcript-backed short-video clip plans and exports. Local media work uses direct `ffmpeg`/`ffprobe` commands only; MCP tools handle OSS upload, TingWu analysis, and LLM JSON planning. ## Default Artifacts Use one output directory per source video: | File | Purpose | | --- | --- | | `metadata.json` | `ffprobe` metadata | | `cover.jpg` | first-frame global cover (fallback) | | `cover-NN.jpg` | per-clip smart keyframe cover (scene-change) | | `decision-log.md` | auto-decision log (orientation, fill, loudnorm, padding) | | `audio.mp3` | extracted audio for TingWu | | `analysis.json` | normalized TingWu result | | `invalid-sentences.json` | unusable sentence indexes | | `segments.json` | slicing plan | | `clip-plan.json` | deterministic clip timings and ffmpeg commands | | `subject-clip-plan.json` | deterministic topic-script clip parts and concat commands | | `clip_results.json` | local ffmpeg execution results | | `clip-manifest.json` | JSON array of delivered clips | | `clip-draft-results.json` | CapCut draft creation results (optional) | | `exports/` | cut videos and text exports | ## Workflow 1. Check media tools: `command -v ffmpeg && command -v ffprobe` If either command is missing, tell the operator to install FFmpeg. Python is not required. 2. Prepare artifacts: ```bash mkdir -p "$DIR" "$DIR/exports" ffprobe -v error -show_format -show_streams -of json "$VIDEO" > "$DIR/metadata.json" ffmpeg -y -i "$VIDEO" -vn -ac 1 -ar 16000 -codec:a libmp3lame -q:a 4 "$DIR/audio.mp3" ffmpeg -y -ss 0 -i "$VIDEO" -frames:v 1 -q:v 2 "$DIR/cover.jpg" ``` 3. Upload audio: Call `upload_live_audio(file_path="$DIR/audio.mp3")`. If storage is local, ask the operator to configure OSS or provide a direct `audio_url`. 4. Create TingWu task: Call `create_live_analysis_task(audio_url=..., auto_chapters_enabled=true, summarization_enabled=true, meeting_assistance_enabled=true, diarization_enabled=false, script_template_enable=true)`. 5. Poll analysis: Call `query_live_analysis_task(task_id=...)` until `status` is `COMPLETED`, then save the JSON to `analysis.json`. 6. Plan cleanup and cuts: - Call `recognize_live_invalid_sentences(sentences=analysis.sentences)` and save `invalid-sentences.json`. - Remove invalid indexes from `analysis.sentences`. - Call `recognize_live_segments(sentences=valid_sentences, ask=optional_user_goal)` and save `segments.json`. - Detect source orientation with `ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 "$VIDEO"` (store `$SRC_W`/`$SRC_H`; `$SRC_W > $SRC_H` is landscape). - Call `build_live_clip_plan(sentences=analysis.sentences, segments=segments.segments, invalid=invalid.invalid, video_path="$VIDEO", output_dir="$DIR", target_mode="vertical", vertical_fill="blur", source_width=$SRC_W, source_height=$SRC_H, target_width=1080, target_height=1920, normalize_audio_loudness=true, head_padding_seconds=0.15, tail_padding_seconds=0.30, min_duration_seconds=5, max_duration_seconds=120)` and save `clip-plan.json`. - Use `recognize_live_subjects` and `complete_live_subject` when the user wants topic-driven clips instead of broad segments, then call `build_live_subject_clip_plan(sentences=analysis.sentences, completions=subject_completions, invalid=invalid.invalid, video_path="$VIDEO", output_dir="$DIR", target_mode="vertical", vertical_fill="blur", source_width=$SRC_W, source_height=$SRC_H, target_width=1080, target_height=1920, normalize_audio_loudness=true, head_padding_seconds=0.15, tail_padding_seconds=0.30, min_duration_seconds=5, max_duration_seconds=120)` and save `subject-clip-plan.json`. - Never hand-convert non-contiguous subject scripts into `segments.json`; use `build_live_subject_clip_plan`. 7. Cut clips: Read each item in the selected plan (`clip-plan.json` or `subject-clip-plan.json`). Before each command, create parent directories for planned `output`, `parts[].output`, and `concat_list_path`. For single-part clips, run `fast_cut_shell` first, then use `ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$OUT"` to read output duration. If the command fails, the output is missing or empty, `ffprobe` fails, or actual duration differs from planned duration by more than `max(1.0s, duration*0.05)`, run `accurate_cut_shell` and read duration again. For multi-part clips, run every `parts[].accurate_cut_shell`, write `concat_list_content` to `concat_list_path`, run `concat_shell`, then read the final duration. Save one execution result per clip to `clip_results.json` with `actual_duration_seconds`; include `part_results` only for multi-part clips. When `fast_cut_shell` is empty (the tool set `method="encode"` because the source is landscape and must be verticalized with a filter), skip straight to `accurate_cut_shell` — the vertical blur/scale filter requires re-encoding and `-c copy` is invalid. The tool-generated `accurate_cut_args` already include `-pix_fmt yuv420p`, `-crf 20`, `-movflags +faststart`, the vertical `-vf` filter, and `-af loudnorm`. 8. Build delivery files: Call `build_live_clip_manifest(source_video="$VIDEO", tingwu_task_id="$TINGWU_TASK_ID", analysis_title=analysis.title, sentences=analysis.sentences, invalid=invalid.invalid, warnings=plan.warnings, rejected=plan.rejected, clips=plan.clips, clip_results=clip_results)` and write: - `clip_manifest` to `clip-manifest.json` as a JSON array with each clip transcript. - `transcript_markdown` to `transcript.md`. - `summary_markdown` to `summary.md`. - `clip_notes_markdown[].markdown` to `clip_notes_markdown[].markdown_path`. 9. Export to CapCut (optional): For each successful clip in `clip_results.json`, create a CapCut/JianYing draft using the `capcut-draft` skill. Each clip becomes its own draft with: - Video segment: the clip's MP4 file (`type: "video"`). The exported MP4 is already 1080×1920, so place it at `scale=1.0` (no hard upscale). - Subtitles: from the clip's `transcript` array, applying the **Short-Video Captions** style from the `capcut-draft` skill (font_size≈10, `bold_width=0.1` for weight, white with `#FFD60A` for selling points/numbers, 0.12 black stroke, 0.8 shadow, `transform.y=-0.78` lower-third, `...` content — do NOT use `` tags, they render literally). Split sentences >8 chars into ≤2 chunks at natural pauses, each its own text segment; time offsets are relative to the clip's start (`subtitle_start = (chunk.start - clip.start) × 1,000,000` microseconds). - Cover: the clip's smart keyframe `cover-NN.jpg` (see Smart Cover below), falling back to `$DIR/cover.jpg`. - Canvas: vertical 9:16 (1080×1920) for short videos - No effects, transitions, or background music added automatically (audio is already loudness-normalized) Save results to `clip-draft-results.json`. Skip this step entirely if CapCut draft root directory is not found. ## Cutting Commands Fast cut: ```bash ffmpeg -y -ss "$START" -i "$VIDEO" -t "$DURATION" -c copy "$OUT" ``` Accurate fallback when copy-mode cuts poorly or fails: ```bash ffmpeg -y -ss "$START" -i "$VIDEO" -t "$DURATION" -c:v libx264 -c:a aac "$OUT" ``` The templates above are the conceptual minimums. In practice, prefer the `accurate_cut_args` returned by `build_live_clip_plan`/`build_live_subject_clip_plan` — when the source is landscape and `target_mode="vertical"`, the tool emits a full re-encode: the chosen vertical `-vf` filter (blur-fill by default), `-c:v libx264 -preset veryfast -crf 20 -pix_fmt yuv420p`, `-c:a aac -b:a 128k`, `-af loudnorm=I=-16:TP=-1.5:LRA=11`, and `-movflags +faststart`. In that case `fast_cut_shell` is empty and `method="encode"`; run `accurate_cut_shell` directly (filtering is incompatible with `-c copy`). The multi-part concat final pass stays `-c copy` because every part is already yuv420p. Single clip example: ```bash START="12.300" DURATION="38.700" OUT="$DIR/exports/01-product-proof.mp4" ffmpeg -y -ss "$START" -i "$VIDEO" -t "$DURATION" -c copy "$OUT" ``` For automated batches, prefer the `fast_cut_shell` and `accurate_cut_shell` fields returned by `build_live_clip_plan`; do not hand-calculate durations. Multi-part subject clips use planned part commands and concat fields: ```bash # for each part ffmpeg -y -ss "$START" -i "$VIDEO" -t "$DURATION" -c:v libx264 -c:a aac "$PART_OUT" # after writing concat_list_content to concat_list_path ffmpeg -y -f concat -safe 0 -i "$CONCAT_LIST" -c copy "$OUT" ``` Duration probe: ```bash ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$OUT" ``` ## Smart Cover `cover.jpg` is the global first-frame fallback. For each clip, grab a representative keyframe instead of frame 0: sample near the clip's ~40% point with scene-change detection, falling back to the midpoint: ```bash PIVOT=$(awk 'BEGIN{printf "%.2f", '"$CLIP_START"' + '"$CLIP_DURATION"' * 0.4}') ffmpeg -y -ss "$PIVOT" -i "$CLIP_PATH" -vf "select=gt(scene\,0.3)" -frames:v 1 -q:v 2 "$DIR/cover-NN.jpg" || \ ffmpeg -y -ss "$(awk 'BEGIN{printf "%.2f", '"$CLIP_DURATION"' / 2}')" -i "$CLIP_PATH" -frames:v 1 -q:v 2 "$DIR/cover-NN.jpg" ``` `NN` is the two-digit clip index. Use `cover-NN.jpg` as that clip's CapCut draft cover; fall back to `cover.jpg` if generation fails. ## Text Export For Markdown transcript exports, write the content directly from `analysis.sentences`: ```markdown # {analysis.title} - [1] 0.00-3.20s 字幕 - [2] 3.20-7.80s 字幕 ``` For clip notes, write the `clip_notes_markdown` returned by `build_live_clip_manifest`; do not invent note content by hand. ## JSON Shapes `analysis.json` uses: `chapters`, `sentences`, `subjects`, `segments`, `invalid`, `qas`, `topics`, `words`, `silents`, `keywords`, `key_sentences`, `templates`, `audio_info`. Sentence objects: `{"index":1,"start":0.0,"end":3.2,"text":"字幕"}` Segment objects: `{"title":"片段标题","description":"说明","thoughts":"剪辑思路","start":1,"end":8}` Invalid objects: `{"index":1,"reason":"直播间欢迎语"}` Clip plan objects: `{"index":1,"title":"片段标题","sentence_start":1,"sentence_end":8,"start":12.3,"end":51.0,"duration":38.7,"output":"...mp4","fast_cut_shell":"ffmpeg ...","accurate_cut_shell":"ffmpeg ...","parts":[...],"transcript":[...]}` Multi-part subject clip fields: `parts`, `concat_list_path`, `concat_list_content`, `concat_shell`, `concat_args`, `script_notes`. Clip manifest is a JSON array of delivered clip objects with status, method, output, duration, actual_duration_seconds, transcript, and optional error fields. `clip_notes_markdown` contains ready-to-write Markdown notes for each clip: `{"index":1,"title":"片段","markdown_path":"...md","markdown":"..."}`. ## Cutting Rules - Keep transcript index boundaries intact; never invent timestamps. - Prefer valid sentences after removing `invalid` indexes. - Pass `head_padding_seconds=0.15, tail_padding_seconds=0.30` to the plan tools so cuts don't clip the first or last word. - Target short-video sweet spots: pass `max_duration_seconds=120` (15-60s is ideal for livestream hooks). Treat clips >120s as too long and record a warning; drop clips shorter than 5s — the MIN is 5s everywhere (draft-skip and red-flag thresholds agree). - Aim for semantic diversity across clips (distinct sentence ranges or topics) so the batch is not a set of near-duplicates. - Favor segments whose first sentence is a conclusion, opinion, pain-point, or contrast (a hook); `complete_live_subject` already forces a 3-5s opening hook for subject clips. - Verticalize for the target platform: pass `target_mode="vertical"` and `vertical_fill="blur"`. Landscape sources get a blur-fill re-encode; already-vertical sources get only `scale`. Audio is loudness-normalized (EBU R128) on re-encode paths, never on `-c copy`. - Use `-c copy` first for speed only when `fast_cut_shell` is non-empty; retry with re-encoding (or go straight to it) if a filter is needed or timestamp accuracy is poor. - For subject clips, preserve selected sentence order unless the LLM explicitly provides a better narrative order. - Do not cut live-only greetings, thanks, countdowns, real-time stock claims, or room-specific promos into short videos unless the user explicitly asks.