An experimental study of video uploading from mobile devices with HTTP streaming

Abstract

Mobile video traffic is growing rapidly in networks due to the continuing user adoption of smartphones and tablet computers. While video viewing is now prevalent on such devices, they also easily enable the recording and uploading of videos for quick publishing on popular video sharing websites. Dynamic Adaptive Streaming over HTTP, or DASH, is a media streaming standard that has recently been developed by the Motion Pictures Experts Group (MPEG) and which has gained attention for its ability to enable media players to render videos with high quality under various network conditions. MPEG-DASH has been ratified at the end of 2011 and is now also known as ISO/IEC 23009 - 1. It is noteworthy that the focus of the initial standard is limited to the efficient server-to-client distribution of videos. In our study we examine the common challenges that manifest themselves during the client-to-server uploading of mobile videos, for example such issues as unstable wireless connections and delayed video availability. We propose a new approach that provides compatibility with DASH and at the same time improves content availability by reducing the end-to-end delay from the recording time of mobile videos to the publishing of the first segment of the multi-bitrate encoded versions through a careful pipelining of the overall process. Our approach features (1) the use of segmentation of videos on the mobile device before uploading and (2) segment-wise transcoding and transformatting on the server side. Therefore, our solution does not require any dedicated encoder for live events while achieving semi-realtime live streaming and providing multi-bitrate content for user-generated videos from smartphones. We report on the performance of our prototype system which uses Android and iOS client devices. © 2012 ACM.