Multiple Description Video Transcoding

Abstract — In this paper we introduce the concept of multiple description video transcoding (MDVT). MDVT converts a single description encoded video into two or more descriptions at an intermediate node in the network. The objective of our MDVT approach is to adapt the video transmission to a multi-radio environment where two or more independent transmission paths exist between the intermediate node and the receiver. The sender does not have to be aware of the transcoding process and the multi-path transmission. MDVT can for instance be applied for multi-mode terminals that are simultaneously connected to two wireless access technologies, e.g., UMTS and WLAN. We compare MDVT with multiple description coding at the sender (MDC-S) as well as with MDC at the intermediate node (MDC-I) where the incoming single description video is decoded and re-encoded into multiple descriptions and the transmission is optimized separately for each path. We present a fast greedy method that can be used to perform multiple description video transcoding in real-time at low complexity. Our experimental results show that we can achieve performance similar to MDC-S where the sender has to be aware of the availability of multiple paths. Compared to MDC-I we observe more than 2 dB gain in reconstruction quality. Index Terms—Video transcoding, multiple description video coding, forward error correction. I

Energy-efficient and QoE-driven adaptive HTTP streaming over LTE

Abstract—LTE networks offer broadband wireless access to mobile users who can benefit from high data rate applications such as video streaming. In order to improve the user satisfaction, Quality-of-Experience (QoE) based resource allocation for mul-tiple streaming users in an LTE cell has been studied. However, the high energy consumption of these applications has not been considered. In this paper, we propose adaptive Discontinuous Reception (DRX) parameters for LTE that reduce the energy con-sumption of mobile devices without degrading the video quality of adaptive HTTP streaming users. Furthermore, we extend the QoE-optimized resource allocation by additionally considering the power consumption of the mobile devices. Simulation results show the benefits of using the proposed adaptive DRX parameters and that further energy saving gains can be achieved by including the power consumption in the optimization problem. I

QoE-driven resource optimization for user generated video content in next generation mobile networks

The increasing popularity of user-generated content and the high quality upstreaming capabilities of mobile phones indicate a preva-lence of video traffic in the uplink of next generation mobile net-works. Need arises for optimizing the network resource allocation while preserving the user satisfaction. In this paper, we propose a service-centric approach for uplink distribution of real-time user-generated content based on the Quality of Experience (QoE) and popularity of the video content. In case of limited network resources, the proposed approach assigns more resources for popular contents while maintaining a minimum guaranteed QoE for the less popular ones. We compare our service-centric approach with a QoE-driven one that does not consider video popularity and evaluate both ap-proaches for the uplink of an LTE system. The simulation results show that a significant gain in terms of average user satisfaction can be achieved. Index Terms — Quality of Experience, service-centric resource allocation, LTE uplink, video popularit

Quality-of-experience driven adaptive HTTP media delivery

driven approach for multi-user resource optimization in Dynamic Adaptive Streaming over HTTP (DASH) over next generation wireless networks. Our objective is to enhance the user experience in adaptive HTTP streaming by jointly considering the character-istics of the media content and the available wireless resources in the operator network. Specifically, we propose a proactive QoE-based approach for rewriting the client HTTP requests at a proxy in the mobile network. The advantage of the proposed approach is its applicability for over-the-top (OTT) streaming as it requires no adaptation of the media content. We compare our proposed scheme to both reactive QoE-optimized and to standard-DASH HTTP streaming. Our contributions are: 1) We first show that standard OTT DASH leads to unsatisfactory performance since the content agnostic resource allocation by the LTE scheduler is far from optimal, and we can achieve a clear QoE improvement when considering the content characteristics. 2) We additionally show that proactively rewriting the client requests gives control of the video content adaptation to the network operator which has better information than the client on the load and radio conditions in the cell. This results in additional gains in user perceived video quality. 3) A standard unmodified DASH client remains unaware of the proposed rewriting of the HTTP requests and can decode and play the redirected media segments. I

WS4_paper2_Ibrahim_Lohmar_El Essaili_d’Allonnes

This paper presents the concepts of overlaying personalized TV1 graphics on the device side, controlled and triggered by Dynamic Adaptive Streaming over HTTP (DASH) in-band events. TV graphics personalization helps engaging viewers in the program and maximize the value of information shown to them. Today’s TV graphics are encoded within the video making it difficult to modify it afterwards. Also for offerings using HTTP Adaptive Bitrate (ABR) technologies, the graphics are encoded with the video. Graphics become unreadable when the ABR algorithm switches to low quality representation e.g. due to bad network conditions. Overlaying the graphics on the player side decouples the quality of the graphics from the quality of the video. This paper describes how to control and personalize TV graphics using timed in-band events defined in MPEG-DASH. Each viewer can resolve the events to different auxiliary media according to its profile. The graphics handling is performed at the client side where each client fetches and overlays the auxiliary media to the video. This allows personalization of graphics and provides high quality overlays independent of the current video qualit