Described herein are methods and systems for video event detection for contextual annotation and synchronization. Exemplary embodiments relate to a method comprising receiving a video stream, extracting a first event from the video stream, determining an index value identifying a location within the video stream corresponding to the first event, and inserting content based on the first event at a location identified by the index value. Further exemplary embodiments relate to a system comprising an event-based data extractor that receives a video stream and extracts a first event from the video stream, a processor that determines an index value identifying a location within the video stream corresponding to the first event, and a video insertion module inserts content based on the first event at a location identified by the index value.