Karaoke Captions
AI-Builder-Club/skills
Generate TikTok/Shorts-style karaoke captions using MLX Whisper, ASS subtitles, and FFmpeg libass.
Understand video content locally using ffmpeg frame extraction and Whisper transcription.
Install Video Understand
$ npx skills add calesthio/OpenMontage --skill video-understand -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install calesthio/OpenMontage video-understand --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/video-understand .claude/skills/video-understand && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "video-understand" agent skill from https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understand into .claude/skills/video-understand/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "video-understand", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understandType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add calesthio/OpenMontage --skill video-understand -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install calesthio/OpenMontage video-understand --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/video-understand .agents/skills/video-understand && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "video-understand" agent skill from https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understand into .agents/skills/video-understand/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "video-understand", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add calesthio/OpenMontage --skill video-understand -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install calesthio/OpenMontage video-understand --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/video-understand .cursor/skills/video-understand && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "video-understand" agent skill from https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understand into .cursor/skills/video-understand/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "video-understand", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/calesthio/OpenMontage.git --path .agents/skills/video-understand--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add calesthio/OpenMontage --skill video-understand -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install calesthio/OpenMontage video-understand --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/video-understand .gemini/skills/video-understand && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "video-understand" agent skill from https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understand into .gemini/skills/video-understand/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "video-understand", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install calesthio/OpenMontage video-understandInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add calesthio/OpenMontage --skill video-understand -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/video-understand .github/skills/video-understand && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "video-understand" agent skill from https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understand into .github/skills/video-understand/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "video-understand", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add calesthio/OpenMontage --skill video-understand -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install calesthio/OpenMontage video-understand --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/video-understand .opencode/skills/video-understand && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "video-understand" agent skill from https://github.com/calesthio/OpenMontage/tree/main/.agents/skills/video-understand into .opencode/skills/video-understand/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "video-understand", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
video-understand- GitHub stars
- 66k
- Token cost
- ~841 tokens
- SKILL.md length
- 190 words
- Files
- 3 (incl. scripts, references)
- Skills in repo
- 41
- Repo updated
- First seen
- Licence
- AGPL-3.0
At a glance
Understand video content locally using ffmpeg frame extraction and Whisper transcription.
- Understanding what a video contains
- SKILL.md covers Prerequisites, Commands, CLI Options and Extraction Modes, plus 2 more sections
- Runs Python scripts from its folder; calls python3, brew and pip
- Transcribing video audio locally
What it does
Video Understand is an agent skill from calesthio/OpenMontage. Understand video content locally using ffmpeg frame extraction and Whisper transcription. No API keys needed. Use when: (1) Understanding what a video contains, (2) Transcribing video audio locally, (3) Extracting key frames for visual analysis, (4) Getting video content without API keys.
Its SKILL.md is about 840 tokens, which your agent loads only when the skill is triggered. The skill folder holds 4 other files, including scripts and reference files (for example `references/output-format.md` and `scripts/understand_video.py`).
It sits in Media & Creative, covering Video production and Transcription. It works with FFmpeg. The repository describes itself as: World's first open-source, agentic video production system. 12 production pipelines, 100+ tools, 700+ agent skill and production-knowledge files. Turn your AI coding assistant… The licence is AGPL-3.0.
When your agent uses it
- Understanding what a video contains
- Transcribing video audio locally
- Extracting key frames for visual analysis
- Getting video content without API keys
Example prompts
- “/video-understand”
Requirements
- Python 3
What it can do on your machine
Read from SKILL.md and the folder at commit 9327439. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 1 file in scripts/ (Python), which the agent can run.
Shell commands in SKILL.md call:
python3brewpip
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use pip, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Video Understand loads about 841 tokens when it runs, and up to ~1.6k if it reads all its reference files. Until then it costs about 77 tokens; SKILL.md has 190 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
SKILL.md
The full file from calesthio/OpenMontage at commit 9327439, republished under its AGPL-3.0 licence (© calesthio). 190 words, ~841 tokens.
Download SKILL.mdSave it as
.claude/skills/video-understand/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.- name
- video-understand
- description
- Understand video content locally using ffmpeg frame extraction and Whisper transcription. No API keys needed. Use when: (1) Understanding what a video contains, (2) Transcribing video audio locally, (3) Extracting key frames for visual analysis, (4) Getting video content without API keys.
video-understand
Understand video content locally using ffmpeg for frame extraction and Whisper for transcription. Fully offline, no API keys required.
Prerequisites
ffmpeg+ffprobe(required):brew install ffmpegopenai-whisper(optional, for transcription):pip install openai-whisper
Commands
# Scene detection + transcribe (default)
python3 skills/video-understand/scripts/understand_video.py video.mp4
# Keyframe extraction
python3 skills/video-understand/scripts/understand_video.py video.mp4 -m keyframe
# Regular interval extraction
python3 skills/video-understand/scripts/understand_video.py video.mp4 -m interval
# Limit frames extracted
python3 skills/video-understand/scripts/understand_video.py video.mp4 --max-frames 10
# Use a larger Whisper model
python3 skills/video-understand/scripts/understand_video.py video.mp4 --whisper-model small
# Frames only, skip transcription
python3 skills/video-understand/scripts/understand_video.py video.mp4 --no-transcribe
# Quiet mode (JSON only, no progress)
python3 skills/video-understand/scripts/understand_video.py video.mp4 -q
# Output to file
python3 skills/video-understand/scripts/understand_video.py video.mp4 -o result.jsonCLI Options
| Flag | Description |
|---|---|
video | Input video file (positional, required) |
-m, --mode | Extraction mode: scene (default), keyframe, interval |
--max-frames | Maximum frames to keep (default: 20) |
--whisper-model | Whisper model size: tiny, base, small, medium, large (default: base) |
--no-transcribe | Skip audio transcription, extract frames only |
-o, --output | Write result JSON to file instead of stdout |
-q, --quiet | Suppress progress messages, output only JSON |
Extraction Modes
| Mode | How it works | Best for |
|---|---|---|
scene | Detects scene changes via ffmpeg select='gt(scene,0.3)' | Most videos, varied content |
keyframe | Extracts I-frames (codec keyframes) | Encoded video with natural keyframe placement |
interval | Evenly spaced frames based on duration and max-frames | Fixed sampling, predictable output |
If scene mode detects no scene changes, it automatically falls back to interval mode.
Output
The script outputs JSON to stdout (or file with -o). See references/output-format.md for the full schema.
{
"video": "video.mp4",
"duration": 18.076,
"resolution": {"width": 1224, "height": 1080},
"mode": "scene",
"frames": [
{"path": "/abs/path/frame_0001.jpg", "timestamp": 0.0, "timestamp_formatted": "00:00"}
],
"frame_count": 12,
"transcript": [
{"start": 0.0, "end": 2.5, "text": "Hello and welcome..."}
],
"text": "Full transcript...",
"note": "Use the Read tool to view frame images for visual understanding."
}Use the Read tool on frame image paths to visually inspect extracted frames.
References
references/output-format.md-- Full JSON output schema documentation
© calesthio, AGPL-3.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 2 other files (scripts, references) in .agents/skills/video-understand of calesthio/OpenMontage.
- SKILL.md
- references/output-format.md
- scripts/understand_video.py
Open the folder on GitHubat commit 9327439
Compare with similar skills
Video Understand next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Video Understand this skillcalesthio/OpenMontage | 66k | — | ~841 | Automated safety check: Pass | AGPL-3.0 | |
| Karaoke CaptionsAI-Builder-Club/skills | 1.3k | — | ~850 | Automated safety check: Pass | None | |
| Ffmpegrendi-api/ffmpeg-cheatsheet | 1.7k | — | ~1.2k | Automated safety check: Pass | None | |
| AutoshortsUpload-Post/skill-autoshorts | 151 | — | ~5.3k | Automated safety check: Notes | MIT | |
| Stage EditOrkas-AI/Orkas-VideoStudio | 499 | — | ~2.4k | Automated safety check: Pass | MIT | |
| Proof Videoopenclaw/openclaw | 392k | — | ~2.4k | Automated safety check: Pass | MIT |
Similar skills
Ffmpeg
rendi-api/ffmpeg-cheatsheet
A skill your agent uses when the user asks for FFmpeg or FFprobe commands, video/audio conversion, trimming, resizing, padding, overlays, subtitles, thumbnails, GIFs, storyboards, slideshows…
Autoshorts
Upload-Post/skill-autoshorts
Daily pipeline that picks one long video from a folder, transcribes it with Whisper, uses Gemini 3 Flash multimodal to find every viral short-form moment, cuts each candidate with FFmpeg, adds a…
Stage Edit
Orkas-AI/Orkas-VideoStudio
Intelligent editing of real user-supplied footage—understand it with transcript/inspected-frame/scene/silence/quality evidence, then choose deterministic timeline operations or a constrained…
Proof Video
openclaw/openclaw
Add subtitles, captions, narration cues, or zoom to a proof video or PR recording using repo-local capture helpers and a system ffmpeg renderer.
Video Production
ffroliva/gflow-cli
A skill your agent uses when the user wants a finished video out of gflow rather than a single clip — a scripted scene, a talking-head or dialogue piece, an explainer, a product montage, a story…
More from calesthio/OpenMontage
All 41 skills in this repoAvatar Video
calesthio/OpenMontage
Create AI avatar videos with precise control over avatars, voices, scripts, scenes, and backgrounds using HeyGen's v2 API.
D3 Viz
calesthio/OpenMontage
Creating interactive data visualisations using d3.js. An agent skill from calesthio/OpenMontage.
Create Video
calesthio/OpenMontage
Create videos from a text prompt using HeyGen's Video Agent.
Threejs World Generation
calesthio/OpenMontage
Build deterministic, editable, free-viewpoint Three.js worlds from text or structured briefs.
Video Edit
calesthio/OpenMontage
Edit videos locally using ffmpeg. An agent skill from calesthio/OpenMontage.
Visual Style
calesthio/OpenMontage
Create, extract, and apply portable visual design systems via visual-style.md files.
Related
Works with
Categories
Questions about Video Understand
What does Video Understand do?
Understand video content locally using ffmpeg frame extraction and Whisper transcription. Video Understand is an agent skill from calesthio/OpenMontage. Understand video content locally using ffmpeg frame extraction and Whisper transcription.
When should I use Video Understand?
Video Understand fits situations like: understanding what a video contains; transcribing video audio locally; extracting key frames for visual analysis; getting video content without API keys.
How do I install Video Understand in Claude Code?
Run `npx skills add calesthio/OpenMontage --skill video-understand -a claude-code`. Or copy the skill folder (.agents/skills/video-understand in calesthio/OpenMontage) into .claude/skills/video-understand in your project. Claude Code loads it when a task matches its description.
How do I install Video Understand in Codex?
Run `npx skills add calesthio/OpenMontage --skill video-understand -a codex`. Or copy the skill folder (.agents/skills/video-understand in calesthio/OpenMontage) into .agents/skills/video-understand in your project. Codex loads it when a task matches its description.
Can I use Video Understand in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add calesthio/OpenMontage --skill video-understand -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/video-understand, .gemini/skills/video-understand, .github/skills/video-understand and .opencode/skills/video-understand in your project.
What does Video Understand need to run?
Going by SKILL.md and its folder, Video Understand needs Python for the scripts in its folder and the command-line tools its instructions call (python3, brew and pip). Our summary lists: Python 3.
Does Video Understand access the network?
SKILL.md contains no URLs. Its commands use pip, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Video Understand safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does Video Understand use?
Video Understand is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Video Understand use?
About 841 tokens (SKILL.md is roughly 3.4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 784 tokens, read only when the agent opens those files.
What are the alternatives to Video Understand?
Skills that share tags, products or a category with Video Understand: Karaoke Captions (AI-Builder-Club/skills, 1.3k stars), Ffmpeg (rendi-api/ffmpeg-cheatsheet, 1.7k stars), Autoshorts (Upload-Post/skill-autoshorts, 151 stars) and Stage Edit (Orkas-AI/Orkas-VideoStudio, 499 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Video Understand?
calesthio (a GitHub user) maintains it in calesthio/OpenMontage, which has 65,930 GitHub stars. The repository holds 41 skills in this directory. The repository was last updated on October 3, 2026.
Source: calesthio/OpenMontage on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.