28,813 research outputs found
Fast intra prediction in the transform domain
In this paper, we present a fast intra prediction method based on separating the transformed coefficients. The
prediction block can be obtained from the transformed and quantized neighboring block generating minimum distortion
for each DC and AC coefficients independently. Two prediction methods are proposed, one is full block search
prediction (FBSP) and the other is edge based distance prediction (EBDP), that find the best matched transformed
coefficients on additional neighboring blocks. Experimental results show that the use of transform coefficients
greatly enhances the efficiency of intra prediction whilst keeping complexity low compared to H.264/AVC
Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures
Distributed video coding (DVC) is a relatively new video coding architecture originated from two fundamental theorems namely, Slepian–Wolf and Wyner–Ziv. Recent research developments have made DVC attractive for applications in the emerging domain of wireless video sensor networks (WVSNs). This paper reviews the state-of-the-art DVC architectures with a focus on understanding their opportunities and gaps in addressing the operational requirements and application needs of WVSNs
3D high definition video coding on a GPU-based heterogeneous system
H.264/MVC is a standard for supporting the sensation of 3D, based on coding from 2 (stereo) to N views. H.264/MVC adopts many coding options inherited from single view H.264/AVC, and thus its complexity is even higher, mainly because the number of processing views is higher. In this manuscript, we aim at an efficient parallelization of the most computationally intensive video encoding module for stereo sequences. In particular, inter prediction and its collaborative execution on a heterogeneous platform. The proposal is based on an efficient dynamic load balancing algorithm and on breaking encoding dependencies. Experimental results demonstrate the proposed algorithm's ability to reduce the encoding time for different stereo high definition sequences. Speed-up values of up to 90× were obtained when compared with the reference encoder on the same platform. Moreover, the proposed algorithm also provides a more energy-efficient approach and hence requires less energy than the sequential reference algorith
Motion correlation based low complexity and low power schemes for video codec
制度:新 ; 報告番号:甲3750号 ; 学位の種類:博士(工学) ; 授与年月日:2012/11/19 ; 早大学位記番号:新6121Waseda Universit
Efficient HEVC-based video adaptation using transcoding
In a video transmission system, it is important to take into account the great diversity of the network/end-user constraints. On the one hand, video content is typically streamed over a network that is characterized by different bandwidth capacities. In many cases, the bandwidth is insufficient to transfer the video at its original quality. On the other hand, a single video is often played by multiple devices like PCs, laptops, and cell phones. Obviously, a single video would not satisfy their different constraints.
These diversities of the network and devices capacity lead to the need for video adaptation techniques, e.g., a reduction of the bit rate or spatial resolution. Video transcoding, which modifies a property of the video without the change of the coding format, has been well-known as an efficient adaptation solution. However, this approach comes along with a high computational complexity, resulting in huge energy consumption in the network and possibly network latency.
This presentation provides several optimization strategies for the transcoding process of HEVC (the latest High Efficiency Video Coding standard) video streams. First, the computational complexity of a bit rate transcoder (transrater) is reduced. We proposed several techniques to speed-up the encoder of a transrater, notably a machine-learning-based approach and a novel coding-mode evaluation strategy have been proposed. Moreover, the motion estimation process of the encoder has been optimized with the use of decision theory and the proposed fast search patterns. Second, the issues and challenges of a spatial transcoder have been solved by using machine-learning algorithms. Thanks to their great performance, the proposed techniques are expected to significantly help HEVC gain popularity in a wide range of modern multimedia applications
Mode decision for the H.264/AVC video coding standard
H.264/AVC video coding standard gives us a very promising future for the
field of video broadcasting and communication because of its high coding
efficiency compared with other older video coding standards. However, high
coding efficiency also carries high computational complexity. Fast motion
estimation and fast mode decision are two very useful techniques which can
significantly reduce computational complexity.
This thesis focuses on the field of fast mode decision. The goal of this thesis is
that for very similar RD performance compared with H.264/AVC video coding
standard, we aim to find new fast mode decision techniques which can afford
significant time savings. [Continues.
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