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Use when rendering or replacing Remotion homepage creator strip videos, especially transparent Chrome WebM and Safari MP4 assets copied into both promo-pages and docs.
Codex または Claude でインストール この Prompt をコピーして Codex、Claude、または他のアシスタントに貼り付けると、Skill ページを確認してインストールできます。
SOC 職業分類に基づく
Add a new effect to @remotion/effects, including implementation, package exports, docs, demos, preview images, Remotion skill updates, tests, formatting, and builds.
Add a new sound effect to @remotion/sfx
Publish Remotion Lambda Chrome binaries to the eu-central-1 test region and update hosted layer and Chrome version references. Use when updating Chrome binaries before full regional rollout.
Document Remotion skill placement. Use when adding, moving, or editing Remotion skills to decide whether a skill belongs in .agents/skills as an internal skill or packages/skills as a public skill.
Guidance for Remotion Studio UI changes where the global CSS reset affects nested elements. Use when editing packages/studio UI, especially when adding wrapper spans, inline icons, labels, buttons, compact rows, or any nested text whose typography, color, sizing, or truncation must stay stable.
Start Remotion Studio from packages/example and open it in the Codex browser. Use when the user invokes /studio or $studio, asks to launch the example Studio, or wants the Remotion Studio dev UI available locally.
| name | homepage-video-assets |
| description | Use when rendering or replacing Remotion homepage creator strip videos, especially transparent Chrome WebM and Safari MP4 assets copied into both promo-pages and docs. |
Use this workflow for homepage creator strip assets such as:
homepage-assets-masterediting-vp9-chrome / editing-safariwhat-is-remotionpackages/brand.cd packages/brand
bunx remotion render <composition-id> /tmp/<asset>-master.mov \
--codec=prores \
--prores-profile=4444 \
--pixel-format=yuva444p10le \
--image-format=png \
--timeout=120000 \
--overwrite
Chrome WebM:
ffmpeg -y -i /tmp/<asset>-master.mov \
-vf scale=540:540 \
-c:v libvpx \
-pix_fmt yuva420p \
-auto-alt-ref 0 \
-an /tmp/<chrome-name>.webm
Safari MP4:
ffmpeg -y -i /tmp/<asset>-master.mov \
-vf scale=540:540 \
-c:v prores_ks \
-profile:v 4 \
-pix_fmt yuva444p10le \
-an /tmp/<asset>-540-prores.mov
avconvert \
--source /tmp/<asset>-540-prores.mov \
--preset PresetHEVCHighestQualityWithAlpha \
--output /tmp/<safari-name>.mp4 \
--replace
cp /tmp/<chrome-name>.webm ../promo-pages/public/img/<chrome-name>.webm
cp /tmp/<safari-name>.mp4 ../promo-pages/public/img/<safari-name>.mp4
cp /tmp/<chrome-name>.webm ../docs/static/img/<chrome-name>.webm
cp /tmp/<safari-name>.mp4 ../docs/static/img/<safari-name>.mp4
Verify the ProRes master has real alpha before converting, and verify the Safari MP4 exists in both folders:
ffmpeg -i /tmp/<asset>-master.mov
ffmpeg -i ../promo-pages/public/img/<safari-name>.mp4
ffmpeg -y -i /tmp/<asset>-master.mov \
-vf alphaextract -frames:v 1 /tmp/<asset>-alpha.png
The master should report prores (4444) and a yuva... pixel format. alphaextract should succeed, and the alpha image should not be fully opaque. A common failure mode is alphaextract succeeding but every sampled pixel is opaque; in that case, the master was rendered with a black/opaque background or a stale opaque master was reused.
Verify every copied Chrome WebM and Safari MP4 is exactly 540x540:
for f in \
../promo-pages/public/img/<chrome-name>.webm \
../promo-pages/public/img/<safari-name>.mp4 \
../docs/static/img/<chrome-name>.webm \
../docs/static/img/<safari-name>.mp4; do
ffmpeg -i "$f"
done
The Safari MP4 should look like the known-good file shape: major_brand: mp42, compatible_brands: isommp41mp42, Video: hevc (Main) (hvc1), 540x540, and handler_name: Core Media Video. If it reports h264 (avc1) or dimensions such as 960x540, it is the wrong file and will render differently in Safari.
Do not add ProRes .mov files to the homepage PR; they are too large. Safari should use the small .mp4 fallback. Chrome should use the transparent .webm.