Reducing Startup Time in MP4 On-demand Video Streaming Services with Movie Atom Caching

Abstract

This paper points out negative effects on startup time of video streaming sessions caused by atom metadata in MP4 movie files. Based on experiments, it is shown that the duration for downloading metadata atom could be relatively large for high-quality full-length movie videos. This leads to noticeable and disturbing startup delay to users when watching MP4 movies online. In order to reduce the startup delay, we present a mechanism, called Movie Atom Caching, that reuses previously downloaded metadata atoms or proactively downloads and caches movie metadata atoms at video players before users actually play the video. The mechanism is implemented in our video streaming prototype system. Experiments on the system show that user experience is improved as startup delay is cut down significantly in typical cases.