HTTP Adaptive Streaming Systems Research Articles

SDN Assisted Codec, Path and Quality Selection for HTTP Adaptive Streaming

Adaptive streaming over HTTP is the dominant video streaming technology for more than a decade. HTTP Adaptive Streaming (HAS) systems provide a framework which enables clients to adapt quality with respect to network fluctuations during streaming, hence to optimize the perceived quality on the client side. Recently, network assistance is integrated with HAS in order to improve underlying network conditions and to provide network-related information to the clients. The performance of HAS systems can be further enhanced if the characteristics of the streamed video are considered. In this paper, we propose a HAS system architecture where Software Defined Networking (SDN) technology is utilized for assisting clients to select the most appropriate video codec and bitrate under the constraint of current network conditions as well as routing the video packet over the appropriate paths. In the proposed architecture, layered video is used, where each additional layer improves the quality. The controller estimates the packet loss probability by taking video codec characteristics, the bitrates of the layers and network capacity into account. Based on these estimations, the controller selects the appropriate codec type and video quality for the clients and manage the network. Simulation results show that the performance of the video streaming architecture can be improved significantly when codec, quality and path selection are jointly considered, and combined with SDN flexibility and advantageous.

Price-Based Controller for Utility-Aware HTTP Adaptive Streaming

HTTP Adaptive Streaming (HAS) can efficiently deliver video to multiple heterogeneous users in a fully distributed way. This might, however, lead to unfair bandwidth utilization among HAS users. Therefore, network-assisted HAS systems have been proposed, where network elements operate alongside clients' adaptation logic to improve user satisfaction. However, current solutions rely on the assumption that network elements have full knowledge of the network status, which isn't always realistic. In this work, the authors propose a practical network-assisted HAS system where the network elements infer the network link congestion using measurements collected from the client endpoints. The congestion-level signal is then used by the clients to optimize their video data requests. The authors' novel controller maximizes overall user satisfaction, and the clients share the available bandwidth fairly from a utility perspective, as demonstrated by simulation results obtained on a network simulator.

Towards Agile and Smooth Video Adaptation in HTTP Adaptive Streaming

HTTP Adaptive Streaming (HAS) is widely deployed on the Internet for live and on-demand video streaming services. Video adaptation algorithms in the existing HAS systems are either too sluggish to respond to congestion level shifts or too sensitive to short-term network bandwidth variations. Both degrade user video experience. In this paper, we formally study the tradeoff between responsiveness and smoothness in HAS through analysis and experiments. We show that client-side buffered video time is a good feedback signal to guide video adaptation. We then propose novel video rate control algorithms that balance the needs for video rate smoothness and high bandwidth utilization. We show that a small video rate margin can lead to much improved smoothness in video rate and buffer size. We also propose HAS designs that can work with multiple servers and wireless connections. We develop a fully functional HAS system and evaluate its performance through extensive experiments on a network testbed and the Internet. We demonstrate that our HAS designs are highly efficient and robust in realistic network environment.

Improving Live Performance in HTTP Adaptive Streaming Systems

While HTTP adaptive streaming (HAS) technology has been very successful, it also generally introduces a significant amount of live delay as experienced by the end viewer. Multiple elements in the video preparation and delivery chain contribute to live delay, and many of these elements are unique to HAS systems versus traditional streaming systems such as RTSP and RTMP. This paper describes how improvements both in the structure of the media, the delivery workflow, and the media player can be combined to produce a system that compares well with broadcast. The paper concludes with a preview of advances in delivery technology (such as HTTP2) that will improve the experience even more in the near future.

Opportunities and Challenges of HTTP Adaptive Streaming

HTTP-based Adaptive Streaming (HAS) has emerged as the prominent technology for the delivery of audiovisual content over the Internet in recent years and has a major impact on network traffic. Although traditional stateful session-based streaming solution based on UDP was used initially for media content delivery, researchers and practitioners soon realize that HAS technology, due to get through firewalls friendly ,transfer NAT easily ,effectively utilize the existing networking infrastructure and provide uninterrupted video streaming service to users with dynamic network conditions and heterogeneous devices, has the potential to improve the Quality of Experiments compared with traditional streaming technologies. Consequently, various HAS media streaming solutions have been proposed and deployed successfully. This paper reviews the state-of-the-art of HAS technology and discoveries achieved by numerous researchers. We describe the basic taxonomy of HTTP adaptive streaming systems and summarize the major issues associated with HAS systems’ design. Then we outline the key challenges and open problems and highlight possible avenues for future directions.