Show HN: SentrySearch – Semantic search over dashcam footage

I built a semantic search CLI for dashcam footage using Gemini Embedding 2's native video embedding.

The interesting part: Gemini Embedding 2 projects raw mp4 video directly into the same vector space as text, no captioning or transcription pipeline. You embed 30-second video chunks as RETRIEVAL_DOCUMENT, embed a text query as RETRIEVAL_QUERY, and cosine similarity just works across modalities.

The tool splits footage into overlapping chunks, indexes them in a local ChromaDB instance, and auto-trims the top match from the original file via ffmpeg.

Cost is about $2.50/hr of footage to index, queries are negligible. Definitely room to optimize: skipping still frames, scene detection for smarter chunking, etc.