CLI#

The package declares two binaries:

• ffmpeg-wasm
• ffprobe-wasm

During local development, call the compiled entrypoints directly after pnpm build.

Probe Duration#

node lib/src/ffprobe-cli.js \
  -v error \
  -show_entries format=duration \
  -of default=noprint_wrappers=1:nokey=1 \
  input.mp4

Extract Speech WAV#

node lib/src/cli.js \
  -hide_banner \
  -loglevel error \
  -i input.mp4 \
  -vn \
  -ac 1 \
  -ar 16000 \
  audio.wav

Make a Fast MP4 Clip#

node lib/src/cli.js \
  -hide_banner \
  -loglevel error \
  -ss 0 \
  -i input.mp4 \
  -t 5 \
  -map 0:v:0 \
  -map 0:a? \
  -c copy \
  -movflags +faststart \
  clip.mp4

This is a stream-copy clip, not H.264 re-encoding. It stays small and LGPL-friendly by avoiding GPL encoders.