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Abstract-In this paper, we describe encryption possibilities for the High Efficiency Video Coding (HEVC) standard under development. Bitstream elements which maintain HEVC compatibility after encryption are listed and their impact on video adaptation is described. From this list, three bitstream elements are selected, namely intra prediction mode difference, motion vector difference sign, and residual sign. These elements provide good protection of the video information and result in 0.0% Bjøntegaard delta bitrate increase because of their equal probability entropy encoding property.

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Abstract-Ensuring and maintaining adequate Quality of Experience towards end-users are key objectives for video service providers, not only for increasing customer satisfaction but also as service differentiator. However, in the case of High Definition video streaming over IP-based networks, network impairments such as packet loss can severely degrade the perceived visual quality. Several standard organizations have established a minimum set of performance objectives which should be achieved for obtaining satisfactory quality. Therefore, video service providers should continuously monitor the network and the quality of the received video streams in order to detect visual degradations. Objective video quality metrics enable automatic measurement of perceived quality. Unfortunately, the most reliable metrics require access to both the original and the received video streams which makes them inappropriate for real-time monitoring. In this article, we present a novel no-reference bitstream-based visual quality impairment detector which enables real-time detection of visual degradations caused by network impairments. By only incorporating information extracted from the encoded bitstream, network impairments are classified as visible or invisible to the end-user. Our results show that impairment visibility can be classified with a high accuracy which enables real-time validation of the existing performance objectives.

End-to-end security for video distribution: the combination of encryption, watermarking, and video adaptation AbstractAbstract. Content distribution applications such as digital broadcasting, video-on-demand services (VoD), video conferencing, surveillance and telesurgery are confronted with difficulties -besides the inevitable compression and quality challenges -with respect to intellectual property management, authenticity, privacy regulations, access control etc. Meeting such security requirements in an end-to-end video distribution scenario poses significant challenges. If the entire content is encrypted at the content creation side, the space for signal processing operations is very limited. Decryption, followed by video processing and re-encryption is also to be avoided as it is far from efficient, complicates key management and could expose the video to possible attacks. Additionally, also when the content is delivered and decrypted, the protection is gone. Watermarking can complement encryption in these scenarios by embedding a message within the content itself containing for example ownership information, unique buyer codes or content descriptions. Ideally, securing the video distribution should therefore be possible throughout the distribution chain in a flexible way allowing the encryption, watermarking and encoding/transcoding operations to commute. This paper introduces the reader to the relevant techniques that are needed to implement such an end-to-end commutative security system for video distribution, and presents a practical solution for encryption and watermarking compliant with H.264/AVC and the upcoming HEVC (High 1 Efficiency Video Coding) video coding standards. To minimize the overhead and visual impact, a practical trade-off between the security of the encryption routine, robust watermarking and transcoding possibilities is investigated. We demonstrate that our combined commutative protection system effectively scrambles video streams, achieving SSIM (Structural Similarity Index) values below 0.2 across a range of practical bit rates, while allowing robust watermarking and transcoding.

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Abstract-HTTP Adaptive Streaming facilitates video streaming to mobile devices connected through heterogeneous networks without the need for a dedicated streaming infrastructure. By splitting different encoded versions of the same video into small segments, clients can continuously decide which segments to download based on available network resources and device characteristics. These encoded versions can, for example, differ in terms of bitrate and spatial or temporal resolution. However, as a result of dynamically selecting video segments, perceived video quality can fluctuate during playback which will impact end-users' Quality of Experience. Subjective studies have already been conducted to assess the influence of video delivery using HTTP Adaptive Streaming to mobile devices. Nevertheless, existing studies are limited to the evaluation of short video sequences in controlled environments. Research has already shown that video duration and assessment environment influence quality perception. Therefore, in this article, we go beyond the traditional ways for subjective quality evaluation by conducting novel experiments on tablet devices in more ecologically valid testing environments using longer duration video sequences. As such, we want to mimic realistic viewing behaviour as much as possible. Our results show that both video content and the range of quality switches significantly influence end-users' rating behaviour. In general, quality level switches are only perceived in high motion sequences or in case switching occurs between high and low quality video segments. Moreover, we also found that video stallings should be avoided during playback at all times.Index Terms-Quality of Experience (QoE), Subjective video quality assessment, HTTP adaptive streaming, Mobile video, Tablet devices.

Abstract-The deblocking filter in the MPEG-4 AVC/H.264 standard is computationally complex because of its high content adaptivity, resulting in a significant number of data dependencies. These data dependencies interfere with parallel filtering of multiple macroblocks on massively-parallel architectures. In this paper, we introduce a novel macroblock partitioning scheme for concurrent deblocking in the MPEG-4 AVC/H.264 standard, based on our idea of Deblocking Filter Independency, a corrected version of the Limited Error Propagation Effect proposed in the literature. Our proposed scheme enables concurrent macroblock deblocking of luma samples with limited synchronization effort, independently of slice configuration, and is compliant with the MPEG-4 H.264/AVC standard. We implemented the method on the massively-parallel architecture of the Graphics Processing Unit (GPU). Experimental results show that our GPU implementation achieves faster-than real-time deblocking at 1309 frames per second for 1080p video pictures. Both software-based deblocking filters and state-of-the-art GPU-enabled algorithms are outperformed in terms of speed by factors up to 10.2 and 19.5 respectively for 1080p video pictures.