video-summarizer

Video Summarizer

Analyzes MP4 files in a directory via the Gemini API and writes a .md summary file next to each video.

Prerequisites

• GEMINI_API_KEY env var must be set
• google-genai installed: py -m pip install google-genai
• Python available as py (Windows) or python3

Workflow

1. Determine the prompt

Check if the user provided a custom prompt or specific extraction instructions.

• No custom prompt -> use the default (structured summary with Title, Summary, Key Points, Takeaways)
• User provides custom instructions -> pass them via --prompt or --prompt-file

A custom prompt completely replaces the default. Examples of custom prompts:

• "Extract all mentioned tools, their prices, and a one-line description for each"
• "List every action item and deadline mentioned in this video"
• "Create a transcript outline with timestamps"

2. Run the script

# Default summary — all videos in current directory (recursive)
py scripts/summarize_videos.py

# Default summary — specific directory
py scripts/summarize_videos.py "C:/path/to/videos"

# Custom prompt (inline) — replaces default summary format
py scripts/summarize_videos.py --prompt "Extract all product names and prices mentioned"

# Custom prompt (from file) — replaces default summary format
py scripts/summarize_videos.py --prompt-file my-prompt.txt

# Both directory and custom prompt
py scripts/summarize_videos.py "C:/path/to/videos" --prompt "List all key decisions made"

3. How Claude should handle user arguments

When the user invokes this skill:

1. If the user specifies a custom prompt or extraction goal (e.g., "extract all tools mentioned", "summarize focusing on pricing", "list action items"), pass it via --prompt "...".
2. If the user provides a prompt file path, pass it via --prompt-file path/to/file.txt.
3. If the user gives no specific instructions, run without --prompt to use the default format.
4. If the user specifies a directory, pass it as the first positional argument.

4. Default output format (when no custom prompt is given)

# [Video Title]

## Summary
[2-3 sentence description]

## Key Points
- point 1
- point 2
- ...

## Core Content & Takeaways
[Central message and key insight]

---
*Auto-generated with Gemini API*

Notes

• Language of the summary matches the language of the video
• Files are auto-deleted from Gemini storage after processing (48h limit)
• Already-summarized videos are skipped on re-runs
• Script path: scripts/summarize_videos.py
• Model: gemini-3-flash-preview