Dash Bitrate-Adaptation Based on Bandwidth and Buffer

Dynamic Adaptive Streaming over HTTP (DASH) is a new video streaming standard that delivers multimedia data using HTTP/TCP. In comparison with other streaming technologies, DASH is able to handle varying network conditions providing smooth streaming by switching bitrates. As a type of HTTP streaming, the key challenge of DASH is how to provide users with the best video quality by a proper adaptation method. Bandwidth and buffer are two crucial factors in the adaptive judgment. In the paper, we propose an optimization function as the bitrate-adaptation which concerns the benefit from video quality and the penalty from stuttering in playback. The benefit is quantified by the bitrates, i.e., the result of the bandwidth-based estimation method. The time of stuttering is what the penalty evaluates once the buffer is underflow while playing back. First, an optimization algorithm is presented to change the streaming bitrates. Second, the experiments show that our composite methods outperform the bandwidth-based methods and the normal video playback.