Dynamic Adaptive Streaming over HTTP (DASH) is referred to as a multimedia streaming standard to deliver high quality multimedia content over the Internet using conventional HTTP Web servers. As a fundamental feature, it enables automatic switching of quality levels according to network conditions, user requirements, and expectations. Currently, the proposed adaptation schemes for HTTP streaming mostly rely on throughput measurements and/or buffer-related metrics, such as buffer exhaustion and levels. In this paper, we propose to enhance the DASH adaptation logic by feeding it with additional information from our evaluation of the users' perception approximating the userperceived quality of video playback. The proposed model aims at conveniently combining TCP-, buffer-, and media content-related metrics as well as user requirements and expectations to be used as an input for the DASH adaptation logic. Experiments have demonstrated that the chosen model enhances the capability of the adaptation logic to select the optimal video quality level. Finally, we integrated all our findings into a real DASH system with QoE monitoring capabilities.

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International audienceWith the emergence of the High Efficiency Video Coding (HEVC) standard, a dataflow description of the decoder part was developed as part of the MPEG-B standard. This dataflow description presented modest framerate results which led us to propose methodolo-gies to improve the performance. In this paper, we introduce architectural improvements by exposing more parallelism using YUV and frame-based parallel decoding. We also present platform optimizations based on the use of SIMD functions and cache efficient FIFOs. Results show an average acceleration factor of 5.8 in the decoding framerate over the reference architecture

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With the standardization of the new High Efficiency Video Coding (HEVC) compression algorithm, a dataflow specification of the HEVC decoding process is also available as part of the standard. This paper presents methodologies to improve and optimize the performance of implementations derived by the dataflow specification. Regarding the architectural aspect of dataflow network, the throughput has been increased by developing more potential parallelism. For the platform aspect, critical processes have been optimized by applying SIMD functions and communications have been improved by cache efficient FIFO implementation. Results revealed an average acceleration factor of 7 in the decoding framerate over the reference dataflow implementation.

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This paper addresses the End-to-End Quality of Service (QoS)

This paper addresses multimedia end user system design for content distribution over heterogeneous networks and terminals, with particular focus on End-to-End quality of service (QoS) control. A multimedia terminal comprising content-related metadata processor, usage environment characteristics provider, end user QoS monitor and H.264's extension Scalable Video Coding (SVC) audio-visual player in coordination under a terminal middleware, has been conceived and implemented. This end user terminal enables End-to-End QoS control for content adaptation solution both in semantic and physical approaches to maximize end user's perceptual experience and minimize resources. Such design approach illustrates a possible architecture for next generation multimedia end user terminal supporting MPEG-21 and H.264 extension SVC codec standards.Index Terms-multimedia end user terminal, end-toend quality of service, MPEG-21, H.264/SVC