video-explorer（视频浏览器）

Video Explorer

Analyze video content through hierarchical frame extraction. Start wide, identify interesting regions, zoom in.

Workflow

1. Overview First

Extract quick thumbnails to see the video timeline:

./skills/video-explorer/scripts/videx overview <video>

This creates small frames (320px) at 10-second intervals in ./videx-out/<name>/overview/.

Read all overview frames to understand video structure:

ls ./videx-out/<name>/overview/

Then use the Read tool on the jpg files to see them.

⚠️ Triplet Rule: Never Single-Frame Sample

A single snapshot tells you nothing about *change*. Overview automatically extracts 3 frames per sample point (t-δ, t, t+δ) so you see motion at each checkpoint. Default δ=0.1s (~3 frames at 30fps) — tight enough to show micro-motion against the long interval between samples.

Triplet files are suffixed _a, _b, _c. Always compare the triplet together.

Configure delta for your needs:

• --triplet=0.1 (default) — subtle motion, UI transitions
• --triplet=0.5 — broader change, scene transitions
• --triplet=1.0 — wide spread, slow-moving content

2. Identify Regions of Interest

After viewing overview frames, identify timestamps where:

• Something interesting is happening
• More detail is needed
• Action is occurring that requires temporal resolution

3. Zoom In

For a time range (more frames, higher resolution):

./skills/video-explorer/scripts/videx range <video> <start>-<end>
# Example: videx range talk.mp4 5:30-6:00

For higher temporal resolution (catch fast action):

./skills/video-explorer/scripts/videx range <video> <start>-<end> --fps=10

For a single frame at full detail:

./skills/video-explorer/scripts/videx zoom <video> <time>
# Example: videx zoom talk.mp4 5:45

4. Iterate

Repeat zoom operations as needed until the question is answered.

Commands Reference

Time Formats

All commands accept these time formats:

• 1:30 = 1 minute 30 seconds
• 01:30:00 = 1 hour 30 minutes
• 90 = 90 seconds
• 1:30.5 = 1 minute 30.5 seconds

Output Structure

Frames are saved with timestamps in filenames for easy reference:

./videx-out/
└── video-name/
    ├── overview/
    │   ├── t_00-00-00.00.jpg
    │   ├── t_00-00-10.00.jpg
    │   └── ...
    ├── range_5-30_6-00/
    │   ├── t_00-05-30.00.jpg
    │   └── ...
    └── zoom/
        └── t_00-05-45.00.jpg

Example Session

User asks: "What happens in this lecture video around the 10 minute mark?"

1. Run overview to understand video structure
2. View overview frames, note that slides change around 9:30-11:00
3. Extract that range: videx range lecture.mp4 9:30-11:00
4. View range frames, find the specific slide transition at 10:15
5. Zoom for detail: videx zoom lecture.mp4 10:15
6. Report findings with specific timestamps