skill-captions

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Translated

2 scripts

Render, preview, validate, and burn consistent production subtitles from QC-passed real-timestamp caption artifacts. Use for AI-video production, washed-video production, IndexTTS2 explainers, practical long-form videos, talking-head edits, Kimi-style dark rounded captions, warm-white translucent captions, subtitle styling, subtitle overlays, or fixing caption size, position, shadow, drift, and 4K scaling. Always pair with ra-audio-to-subtitles when final word timestamps do not already exist.

1installs

Sourcepluviobyte/rnskill

Added on2026-10-21

NPX Install

npx skill4agent add pluviobyte/rnskill skill-captions

SKILL.md Content

View Translation Comparison →

Skill-字幕

Separate subtitle timing from subtitle appearance:

Let
```
ra-audio-to-subtitles
```
own ASR, phrase grouping, timestamps, SRT/VTT, and
```
caption-qc.json
```
.
Let this skill own typography, panel geometry, fixed anchoring, preview, overlay rendering, burn-in, and render QC.
Never estimate production timing from character count, scene duration, or TTS segment duration.

Required workflow

Lock the final narration audio or final merged video.
Run
```
ra-audio-to-subtitles
```
unless the project already has the canonical caption artifacts described in
```
references/timing-contract.md
```
.
Require
```
caption-qc.json
```
to report
```
status: pass
```
.
Select a style from
```
references/style-registry.json
```
. Use
```
anchor-dark
```
when the contract does not specify another style.
Generate a representative still preview before rendering a full video.
Inspect the preview against
```
references/layout-qc.md
```
.
Render the captioned derivative. Preserve the clean video and portable SRT/VTT.
Run
```
scripts/validate_caption_render.py
```
and archive its JSON report.

Registered styles

anchor-dark

reproduces the approved Kimi K3 subtitle treatment: STHeiti Medium, warm white text, a tight charcoal translucent rounded panel, no text stroke, no text shadow, no large panel shadow, and a fixed bottom-center anchor. Read

references/style-anchor-dark.md

before changing its values.

anchor-light

keeps the exact same typography, size, padding, width, bottom anchor, line fitting, and resolution scaling as

anchor-dark

. Only its surface changes: dark ink on a warm-white translucent panel with a fine border and subtle soft shadow. Read

references/style-anchor-light.md

before changing its values. This is the second registered style;

anchor-dark

remains the default.

Scale every 1080p metric by

target_height / 1080

. Render 4K captions at 2× their 1080p measurements; never upscale a rasterized 1080p subtitle layer.

Commands

Preview a QC-passed project:

bash

python3 .claude/skills/skill-captions/scripts/render_captions.py \
  final.mp4 media/captions/captions.json \
  --qc media/captions/caption-qc.json \
  --preview qc/caption-preview.png \
  --preview-only

Burn the default style:

bash

python3 .claude/skills/skill-captions/scripts/render_captions.py \
  final-clean.mp4 media/captions/captions.json \
  --qc media/captions/caption-qc.json \
  --out renders/final-captioned.mp4 \
  --preview qc/caption-preview.png

Burn the light translucent style:

bash

python3 .claude/skills/skill-captions/scripts/render_captions.py \
  final-clean.mp4 media/captions/captions.json \
  --qc media/captions/caption-qc.json \
  --style anchor-light \
  --out renders/final-captioned.mp4 \
  --preview qc/caption-preview.png

Skip an interval that already contains burned captions:

bash

python3 .claude/skills/skill-captions/scripts/render_captions.py \
  final-clean.mp4 media/captions/captions.json \
  --qc media/captions/caption-qc.json \
  --exclude 0:23.936 \
  --out renders/final-captioned.mp4

Create a reusable transparent caption band:

bash

python3 .claude/skills/skill-captions/scripts/render_captions.py \
  final-clean.mp4 media/captions/captions.json \
  --qc media/captions/caption-qc.json \
  --overlay-out renders/caption-band.mov

Validate the result:

bash

python3 .claude/skills/skill-captions/scripts/validate_caption_render.py \
  --source final-clean.mp4 \
  --render renders/final-captioned.mp4 \
  --captions media/captions/captions.json \
  --qc media/captions/caption-qc.json \
  --out qc/caption-render-qc.json

Hard rules

Use the final audio/video as the only timing source.
Consume
```
captions.json
```
start/end values directly.
Refuse final burn-in when caption QC is missing or failed.
Keep a fixed bottom anchor. Let multiline panels grow upward.
Keep captions inside the frame and clear of titles, UI, faces, and PiP.
Keep English model/product tokens intact.
Preserve one canonical caption timeline across renderers.
Keep the clean master; a burned-caption MP4 is a derivative.
For a new or materially changed style, show a short preview before the full render.
Do not add karaoke, behind-person typography, VFX captions, or animated hero words unless the user explicitly requests the separate
```
embedded-captions
```
lane.

Integration contract

Video orchestrators should call this skill after

ra-audio-to-subtitles

. Handoff contracts may set

caption_style

to

anchor-dark

or

anchor-light

; otherwise use

anchor-dark

. Renderers may reproduce the registered CSS in Remotion or HyperFrames, but must preserve the style metrics and fixed-anchor behavior.

skill-captions

NPX Install

Tags

SKILL.md Content

Skill-字幕

Required workflow

Registered styles

Commands

Hard rules

Integration contract