This paper proposes a video quality adaptation algorithm based on the Dynamic Adaptive Streaming over HTTP (DASH) standard for on-demand video services. When a video is encoded with constant quality, the resulting bitstream has variable bitrate due to the inherent nature of the video encoding process. The proposed algorithm, called Look Ahead, takes into account this bitrate variability in order to calculate, on the fly, the appropriate quality level that minimizes the number of interruptions during the playback. …