Viral Video Platform Specifications

Use this skill to choose export settings for TikTok, YouTube Shorts, Instagram Reels, Facebook Reels, Snapchat Spotlight, Twitter/X, Pinterest, LinkedIn, and mobile-browser playback. This SKILL is a lean orchestrator; detailed platform tables, commands, and recipes are preserved in references/platform-details-and-recipes.md.

Quick Reference

Universal Social Export Baseline

ffmpeg -i input.mp4 \
  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black,setsar=1,fps=30" \
  -c:v libx264 -preset medium -crf 22 -profile:v high -level 4.1 \
  -c:a aac -b:a 192k -ar 48000 -ac 2 \
  -pix_fmt yuv420p -movflags +faststart \
  output_social.mp4

Adjust loudness, duration, bitrate, and metadata per platform from the reference file.

Core Workflow

1. Verify ffmpeg -version; prefer current stable builds for security and codec fixes.
2. Identify target platform(s) and whether the video is native-app upload or mobile-browser playback.
3. Normalize to vertical 9:16 unless the platform or campaign calls for square/horizontal.
4. Use H.264/AAC for the broadest acceptance. Use VP9 only when intentionally targeting YouTube/WebM.
5. Apply platform loudness targets: TikTok/Reels often around -10 to -12 LUFS; YouTube around -14 LUFS; Facebook around -13 LUFS.
6. Keep -pix_fmt yuv420p and -movflags +faststart for compatibility.
7. Verify output with ffprobe before upload.

Key Gotchas

• All major social platforms re-encode uploads; high-quality H.264 is usually a better upload source than HEVC/AV1 for social delivery.
• For web/mobile-browser playback, profile/level, yuv420p, and faststart matter more than platform upload limits.
• Keep captions and UI out of unsafe top/bottom regions, especially lower 35% on Reels-style interfaces.
• Two-pass bitrate control is useful when a platform file-size ceiling is strict.

Reference Map

• references/platform-details-and-recipes.md - Full preserved reference: per-platform spec tables, FFmpeg presets, two-pass examples, multi-platform export script, file-size calculation, codec comparison, mobile-safe playback, color grading, text/caption readability, verification commands, sources.

Related Skills

• viral-video-animated-captions - CapCut-style caption generation
• viral-video-hook-templates - Hook patterns and retention tactics
• ffmpeg-animation-timing-reference - Timing, readability, sync, and platform pacing
• ffmpeg-command-syntax - Correct option placement