animation-export-presets

Turns a rendered Remotion composition into files that play where they are going. It fixes the failures that show up after "the render worked": yuv444p or odd-sized MP4s LinkedIn rejects, untagged colour that shifts on some players, moov-at-the-end files that stall, PowerPoint clips that scrub badly or show a seam, GIFs posted to LinkedIn as a static image, and 4K rooms fed a soft 1080p upscale. Every preset carries its source URL and date in assets/presets.json.

When to use / when NOT to use

Use when the animation is done and someone needs the MP4/GIF for a platform, a different size or fps, a fix for a file a platform or PowerPoint refused, or a check that a delivered file matches a preset.

Do NOT use for: animating (smooth-motion-choreography), judging the look of frames (animation-frame-qa), storyboards or layout, compressing screen recordings, deck conversion, uploading or writing the post, or installing ffmpeg.

Workflow

1. Preconditions: animation.config.json has remotion_license_basis (the renderer refuses otherwise), every target in it has a composition (Root.tsx), npx remotion compositions src/index.ts lists them, ffmpeg and ffprobe are on PATH.
2. Pick presets from assets/presets.json: linkedin-4x5 (default feed), linkedin-1x1, linkedin-9x16, linkedin-16x9, pptx-16x9, pptx-4k, gif-loop, custom (composition custom from the storyboard's custom_size). Why each is what it is: references/delivery-specs.md.
3. Render from the project root (the script runs Remotion inside --project):

   python3 "${CLAUDE_SKILL_DIR}/scripts/render.py" --project . --preset linkedin-4x5 --preset pptx-16x9

   One master per composition (CRF 10, PNG frames, BT.709, with a sidecar recording the storyboard and flags it came from), then one ffmpeg pass per deliverable. Each deliverable is checked before it replaces out/<preset>.mp4|gif; a failed check leaves the previous file untouched. --reuse-masters reuses a master whose sidecar matches; --input file.mp4 re-encodes an existing file (the repair path for "PowerPoint won't play it"); --dry-run prints the commands.
4. Check any file against its preset (the renderer already did this for what it published; run it on files from elsewhere or after edits):

   python3 "${CLAUDE_SKILL_DIR}/scripts/check_output.py" out/linkedin-4x5.mp4 --preset linkedin-4x5 --project .

   Expected size and fps come from the preset and the project's storyboard.json (custom_size for the custom preset). Checks: container, codec, profile, pixel format, even dimensions, exact fps and platform fps range, duration bounds, byte floor and cap, bitrate range, BT.709 tags, faststart atom order, no audio, GIF infinite-loop extension, full decode. Fix the source of a failure (usually the composition or the storyboard), never the checker.
5. Hand off: file paths per preset, the checker's summary, and the platform notes below. Next: animation-frame-qa looks at the frames before delivery.

Output spec

• out/<preset>.mp4 or .gif per requested preset, plus out/masters/*.mp4.
• check_output.py exits 0 for every deliverable.
• The reply states, per file, where it is meant to go and any handling note (PowerPoint: insert, Start Automatically, Loop until Stopped for loops, do not run Compress Media; LinkedIn: upload the MP4, add the credit line from ATTRIBUTION.md to the post text if one exists; GIF: README/email/desktop decks only).

Gotchas

• LinkedIn's video platform does not accommodate animated GIFs, and PowerPoint for the web cannot play them. GIF is for README, email and desktop decks.
• PowerPoint on Windows and Mac plays H.264/AAC MP4; HEVC, VP9 and ProRes are not in Microsoft's supported list, WebM needs an extension, and alpha video is not a documented insert format: bake the slide background colour into the render.
• Compress Media (Windows only) re-encodes to 1080p/720p/480p and drops embedded subtitles; tell the presenter to leave it off.
• Remotion tags only the colour matrix; primaries and transfer are tagged in the ffmpeg pass (h264_metadata bitstream filter). Untagged video reads as BT.601 in some players and brand colours shift.
• LinkedIn re-encodes: CRF 18 is this skill's policy for the upload; thin saturated strokes and long gradients are what break in the re-encode, not bitrate. The checker also enforces LinkedIn's 75 KB and 192 Kbps floors that sparse vector clips can miss.
• 4K for PowerPoint is --scale 2 on the 1080p composition, not a bigger design; everything scales because tokens are fractions of the frame.
• Rendering at 60 fps doubles time and no target requires it; keep the storyboard's fps.
• Remotion's free license covers individuals, companies of up to 3 people and non-profits; the renderer stops without a recorded basis (remotion.pro/license).

Pointers

• assets/presets.json — the presets with source URLs, dates and the reason for each value.
• scripts/render.py — masters + checked deliverables; --input, --dry-run, --reuse-masters, --self-test.
• scripts/check_output.py — per-preset checks against the project's storyboard; --self-test.
• references/delivery-specs.md — LinkedIn, PowerPoint, GIF and encoding facts with sources.