video-still-animator
GitHub将单张静态图片转换为带有缓慢缩放效果的MP4视频，作为AI视频生成被内容审核拦截时的备用方案。利用ffmpeg实现，确保下游合并流程能继续处理完整片段。
Trigger Scenarios
Install
npx skills add opensquilla/opensquilla --skill video-still-animator -g -y
SKILL.md
Frontmatter
{
"name": "video-still-animator",
"metadata": {
"opensquilla": {
"risk": "medium",
"requires": {
"bins": [
"ffmpeg"
],
"anyBins": [
"python",
"python3"
]
},
"capabilities": [
"filesystem-write",
"process-control"
]
}
},
"entrypoint": {
"args": [
"--input",
"{{ with.input_image }}",
"--output",
"{{ with.output_path }}",
"--duration",
"{{ with.duration | default(5) }}",
"--width",
"{{ with.width | default(720) }}",
"--height",
"{{ with.height | default(1280) }}",
"--fps",
"{{ with.fps | default(24) }}",
"--zoom-rate",
"{{ with.zoom_rate | default(0.0015) }}"
],
"parse": "text",
"command": "python {baseDir}\/scripts\/animate.py",
"timeout": 120
},
"provenance": {
"origin": "opensquilla-original",
"license": "Apache-2.0"
},
"description": "Turn a single still image (PNG\/JPG) into a short MP4 with a slow Ken-Burns zoom and a silent audio track. Pure ffmpeg wrapper. Designed as the on_failure substitute for AI video-gen steps that get blocked by content moderation: when seedance refuses, this skill emits a valid replacement clip from the already-generated still so a downstream merge can still produce a complete deliverable."
}
video-still-animator — Ken-Burns fallback clip from a still
Produces a short MP4 from a single PNG/JPG using ffmpeg's zoompan
filter, so a downstream merge step still has a clip for every shot when
an upstream AI video generation step gets blocked.
Why this skill exists
seedance-2-prompt (and any platform-moderated video model) can refuse
individual requests for reasons that have nothing to do with the
prompt's narrative quality:
- input photo contains a recognisable real person face
- output audio gets flagged by the safety classifier
- the moderation model's similarity threshold drifts day to day
In meta-short-drama we always have a fresh PNG on disk before the
seedance call runs, so the cheapest "the show must go on" fallback is to
turn that PNG into a Ken-Burns clip and feed it to the merger. The clip
won't have the camera motion the prompt asked for, but the character,
framing, and timing will still match the script.
Inputs (with:)
| key | required | default | notes |
|---|---|---|---|
input_image |
yes | — | PNG or JPG path. |
output_path |
yes | — | Output .mp4 path. Parent dir created if missing. |
duration |
no | 5 |
Clip length in seconds. |
width |
no | 720 |
Output width. Match the merge step's pipeline. |
height |
no | 1280 |
Output height. 720x1280 = 9:16. |
fps |
no | 24 |
Output frame rate. |
zoom_rate |
no | 0.0015 |
Per-frame zoom delta; 0.0015 over 5s ≈ 1.18× final zoom. |
Output specs
- H.264 video at the requested resolution + fps
- AAC silent audio track (so merge steps that demux/remux audio do not trip on a missing stream)
+faststartMP4 (web playback friendly)
Dependencies
- ffmpeg ≥ 5.0 on PATH (or pass
--ffmpeg-pathdirectly).
On Windows the script also probes the winget Gyan.FFmpeg install path,
Scoop, Chocolatey, and C:\Program Files\ffmpeg\bin before giving up.
Use as on_failure substitute
In a meta-skill DAG, hang it off the real video step:
- id: shot1_video
kind: skill_exec
skill: seedance-2-prompt
on_failure: shot1_video_fallback
with: { ... }
- id: shot1_video_fallback
kind: skill_exec
skill: video-still-animator
with:
input_image: "{{ inputs.workspace_dir }}/.../1_shot.png"
output_path: "{{ inputs.workspace_dir }}/.../1_shot.mp4"
The fallback must be a standalone step (no depends_on, no own
on_failure) per the meta-skill engine rules. The PNG must already
exist on disk by the time the parent step fails — that's true here
because the image step always runs before the video step.
Limits
- Static framing only. The zoom is uniform centre-anchored; no pan, no rotation, no parallax. For richer fallback motion, generate a fresh set of stills and call this multiple times.
- No real audio. The intent is a placeholder that survives the merge; add a real soundtrack downstream if needed.
- ffmpeg version drift: very old ffmpeg (<4) may not accept the exact
zoompanfilter syntax; install ≥ 5.
Version History
- 7f72a32 Current 2026-07-05 18:40
