# Send Skill Video Caption Overlay to your agent
Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually.
## Fast path
- Download the package from Yavira.
- Extract it into a folder your agent can access.
- Paste one of the prompts below and point your agent at the extracted folder.
## Suggested prompts
### New install

```text
I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Tell me what you changed and call out any manual steps you could not complete.
```
### Upgrade existing

```text
I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Summarize what changed and any follow-up checks I should run.
```
## Machine-readable fields
```json
{
  "schemaVersion": "1.0",
  "item": {
    "slug": "skill-video-caption-overlay",
    "name": "Skill Video Caption Overlay",
    "source": "tencent",
    "type": "skill",
    "category": "开发工具",
    "sourceUrl": "https://clawhub.ai/Zero2Ai-hub/skill-video-caption-overlay",
    "canonicalUrl": "https://clawhub.ai/Zero2Ai-hub/skill-video-caption-overlay",
    "targetPlatform": "OpenClaw"
  },
  "install": {
    "downloadUrl": "/downloads/skill-video-caption-overlay",
    "sourceDownloadUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=skill-video-caption-overlay",
    "sourcePlatform": "tencent",
    "targetPlatform": "OpenClaw",
    "packageFormat": "ZIP package",
    "primaryDoc": "SKILL.md",
    "includedAssets": [
      "SKILL.md",
      "scripts/example_captions.json",
      "scripts/overlay.py"
    ],
    "downloadMode": "redirect",
    "sourceHealth": {
      "source": "tencent",
      "slug": "skill-video-caption-overlay",
      "status": "healthy",
      "reason": "direct_download_ok",
      "recommendedAction": "download",
      "checkedAt": "2026-05-09T01:36:13.465Z",
      "expiresAt": "2026-05-16T01:36:13.465Z",
      "httpStatus": 200,
      "finalUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=skill-video-caption-overlay",
      "contentType": "application/zip",
      "probeMethod": "head",
      "details": {
        "probeUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=skill-video-caption-overlay",
        "contentDisposition": "attachment; filename=\"skill-video-caption-overlay-1.0.0.zip\"",
        "redirectLocation": null,
        "bodySnippet": null,
        "slug": "skill-video-caption-overlay"
      },
      "scope": "item",
      "summary": "Item download looks usable.",
      "detail": "Yavira can redirect you to the upstream package for this item.",
      "primaryActionLabel": "Download for OpenClaw",
      "primaryActionHref": "/downloads/skill-video-caption-overlay"
    },
    "validation": {
      "installChecklist": [
        "Use the Yavira download entry.",
        "Review SKILL.md after the package is downloaded.",
        "Confirm the extracted package contains the expected setup assets."
      ],
      "postInstallChecks": [
        "Confirm the extracted package includes the expected docs or setup files.",
        "Validate the skill or prompts are available in your target agent workspace.",
        "Capture any manual follow-up steps the agent could not complete."
      ]
    }
  },
  "links": {
    "detailUrl": "https://openagent3.xyz/skills/skill-video-caption-overlay",
    "downloadUrl": "https://openagent3.xyz/downloads/skill-video-caption-overlay",
    "agentUrl": "https://openagent3.xyz/skills/skill-video-caption-overlay/agent",
    "manifestUrl": "https://openagent3.xyz/skills/skill-video-caption-overlay/agent.json",
    "briefUrl": "https://openagent3.xyz/skills/skill-video-caption-overlay/agent.md"
  }
}
```
## Documentation

### Video Caption Overlay

Animated pill-style caption overlays for short-form video. No Premiere, no CapCut — pure Python.

### Usage

uv run --with moviepy --with pillow scripts/overlay.py \\
  --video base.mp4 \\
  --output final.mp4 \\
  --captions scripts/example_captions.json \\
  --audio music.mp3 \\
  --audio-start 8 \\
  --audio-vol 0.5

No --audio if you want to keep the original video audio.

### Custom fonts

--font-black /path/to/Montserrat-Black.ttf \\
--font-bold  /path/to/Montserrat-Bold.ttf

Falls back to Montserrat from ~/.local/share/fonts/ if not specified.

### captions.json format

Array of phases — each phase is a time window with one or more pill lines stacked vertically.

[
  {
    "start": 0,
    "end": 3.2,
    "y_frac": 0.06,
    "lines": [
      {
        "text": "POV:",
        "size": 28,
        "bold": true,
        "bg": [0, 195, 255],
        "fg": [0, 0, 0],
        "bg_opacity": 0.9,
        "px": 20, "py": 9, "r": 12
      },
      {
        "text": "drink more water",
        "size": 50,
        "bg": [255, 255, 255],
        "fg": [0, 0, 0]
      }
    ]
  }
]

FieldTypeDefaultDescriptionstartfloatrequiredPhase start time (seconds)endfloatrequiredPhase end time (seconds)y_fracfloat0.06Vertical position as fraction of video heightlines[].textstringrequiredCaption textlines[].sizeint50Font size (px)lines[].boldboolfalseUse bold font (vs black/heavy)lines[].bg[R,G,B][255,255,255]Pill background colorlines[].fg[R,G,B][0,0,0]Text colorlines[].bg_opacityfloat0.93Pill background opacity (0–1)lines[].pxint26Horizontal paddinglines[].pyint13Vertical paddinglines[].rint18Border radius

### PIL textbbox fix

PIL's textbbox((0,0), text, font) returns (x0, y0, x1, y1) where y0 is a non-zero offset (typically 7–15px depending on font size). Drawing text at (x, y) without compensating for this offset causes text to appear below the pill's visual center.

Fix implemented in pill():

bb    = draw.textbbox((0, 0), text, font=font)
x_off, y_off = bb[0], bb[1]
vis_w = bb[2] - bb[0]   # actual visual width
vis_h = bb[3] - bb[1]   # actual visual height

# Compensate offsets when drawing text
tx = cx - vis_w // 2 - x_off
ty = y - y_off
draw.text((tx, ty), text, font=font, fill=fg)

### Emoji note

NotoColorEmoji.ttf fails with PIL at arbitrary sizes (bitmap font with limited supported sizes). Use text alternatives ("Free delivery" instead of "Free delivery 🚚") for reliable rendering.

### Example output

See scripts/example_captions.json for the full 3-phase TikTok ad structure:

Phase 1 (0–3.2s): Hook — top-screen pill stack
Phase 2 (2.8–5.8s): Product claim — overlapping fade
Phase 3 (5.3–8.0s): CTA — bottom-screen price + delivery + bio link
## Trust
- Source: tencent
- Verification: Indexed source record
- Publisher: Zero2Ai-hub
- Version: 1.0.0
## Source health
- Status: healthy
- Item download looks usable.
- Yavira can redirect you to the upstream package for this item.
- Health scope: item
- Reason: direct_download_ok
- Checked at: 2026-05-09T01:36:13.465Z
- Expires at: 2026-05-16T01:36:13.465Z
- Recommended action: Download for OpenClaw
## Links
- [Detail page](https://openagent3.xyz/skills/skill-video-caption-overlay)
- [Send to Agent page](https://openagent3.xyz/skills/skill-video-caption-overlay/agent)
- [JSON manifest](https://openagent3.xyz/skills/skill-video-caption-overlay/agent.json)
- [Markdown brief](https://openagent3.xyz/skills/skill-video-caption-overlay/agent.md)
- [Download page](https://openagent3.xyz/downloads/skill-video-caption-overlay)