In some implementations, each of the video sources 522 includes one or more video cameras 118 that capture video and send the captured video to the server system 508 substantially in real-time. In some implementations, each of the video sources 522 optionally includes a controller device (not shown) that serves as an intermediary between the one or more cameras 118 and the server system 508. The controller device receives the video data from the one or more cameras 118, optionally, performs some preliminary processing on the video data, and sends the video data to the server system 508 on behalf of the one or more cameras 118 substantially in real-time. In some implementations, each camera has its own on-board processing capabilities to perform some preliminary processing on the captured video data before sending the processed video data (along with metadata obtained through the preliminary processing) to the controller device and/or the server system 508. In some implementations, the captured video is stored in a local storage (not shown) prior to being uploaded to the server system 508.