Tools

Write videos in HTML, CSS and frame-seekable animations, preview them from the CLI and render deterministic MP4s. Comes with agent skills for product launch videos, captions and talking-head re-edits. Maintained by HeyGen; needs Node.js 22+ and FFmpeg.

Command-line toolkit for transcoding, cutting, joining, frame extraction and streaming of audio and video, including ffmpeg, ffprobe and ffplay. A core dependency for agents handling media. The GitHub repo is the official mirror.

All-in-one video translation and dubbing: chains speech recognition, subtitle translation, multi-speaker AI voiceover and audio-video muxing, with local or online models like Faster-Whisper, DeepSeek and Edge-TTS. cli.py supports headless batch runs. Needs FFmpeg.

Automatically aligns subtitle timing to a video's audio track, fixing translated subtitles that drift out of sync, or syncs against an already aligned subtitle file. Runs locally with no account; install Python and FFmpeg first.

High-quality GIF encoder built on pngquant: turns video frames or PNG sequences into animations, using cross-frame palettes and temporal dithering for thousands of colors per frame. Can take video piped straight from ffmpeg.