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Video optimization ​

Videos used as web banners, hero backgrounds, and short video reviews should be compressed before storing on S3.

Installation ​

Install ffmpeg via Homebrew:

bash
brew install ffmpeg

Usage ​

The script at scripts/media/compress-videos.sh handles all video compression. It scans a directory for .mp4 files and compresses them with H.264/CRF-based encoding.

Silent videos (banners, backgrounds) ​

Strips the audio track by default — the single biggest win for reducing file size on decorative videos:

bash
./scripts/media/compress-videos.sh /path/to/videos

Videos with audio (reviews, shorts) ​

Pass --keep-audio to encode audio as AAC at 96k:

bash
./scripts/media/compress-videos.sh --keep-audio /path/to/videos

Capping resolution ​

Some source videos are recorded at 1440p or 4K but are only ever displayed at 1080p or smaller on the site. The extra pixels just waste bandwidth. Pass --cap-resolution to scale videos above 1080p down to 1080p while keeping lower resolutions native:

bash
./scripts/media/compress-videos.sh --cap-resolution /path/to/videos

Flags can be combined in any order:

bash
./scripts/media/compress-videos.sh --keep-audio --cap-resolution /path/to/videos

Output files are saved alongside the originals with a -minified.mp4 suffix.

Flags explained ​

  • -c:v libx264 — Sets the video codec to H.264 (AVC). Universal web standard that plays on everything from 2010-era phones to modern smart TVs.
  • -crf 26 — Constant Rate Factor. Instead of a fixed bitrate, CRF ensures consistent quality throughout the video. 26 is an efficient "web-light" setting — smaller than the default 23, but still looks sharp.
  • -preset slower — Tells the encoder to spend more time analyzing pixels to find better compression. Results in a smaller file size for the same quality level.
  • -pix_fmt yuv420p (format=yuv420p in -vf) — Ensures the color space is compatible with all web browsers. Without this, some high-end camera footage (10-bit color) won't play in Chrome or Safari.
  • scale=-2:'min(1080,ih)' — Caps the height at 1080 pixels. Videos at 1080p or below are untouched; anything above (1440p, 4K) is scaled down. The -2 keeps the width proportional and divisible by 2 (required by H.264). Only applied when --cap-resolution is passed.
  • -an — Short for "Audio None." Removes the audio track completely (default behavior).
  • -c:a aac -b:a 96k — AAC audio at 96 kbps, used when --keep-audio is passed.
  • -movflags +faststart — Moves the file's metadata index to the beginning so the video starts playing instantly while the rest downloads. Essential for the web.