Spatio-Temporal Parallelization Scheme for HEVC Encoding on Multi-Computer Systems

High Efficiency Video Coding (HEVC) sets the scene for economic video transmission and storage, but its inherent computational complexity calls for efficient parallelization techniques. This paper introduces and compares three different parallelization strategies for HEVC encoding on multi-computer systems: 1) spatial parallelization scheme, where input video frames are divided into slices and distributed among available computers; 2) temporal parallelization scheme, where input video is distributed among computers in groups of consecutive frames; 3) spatio-temporal parallelization scheme that combines the proposed spatial and temporal approaches. All these three schemes were benchmarked as part of the practical Kvazaar open-source HEVC encoder. Our experimental results on 2–5 computer configurations show that using the spatial scheme gives 1.65×–2.90× speedup at the cost of 4.16%–13.09% bitrate loss over a single-computer setup. The respective speedup with temporal parallelization is 1.86×–3.26× without any coding overhead. The spatio-temporal scheme with 2 slices was shown to offer the best load-balancing with 1.81×–3.55× speedups and a constant coding loss of 4.16%.acceptedVersionPeer reviewe

Design Space Exploration of Practical VVC Encoding for Emerging Media Applications

Versatile Video Coding (VVC/H.266) is the latest video coding standard designed for a broad range of next-generation media applications. This paper explores the design space of practical VVC encoding by profiling the Fraunhofer Versatile Video Encoder (VVenC). All experiments were conducted over five 2160p video sequences and their downsampled versions under the random access (RA) condition. The exploration was performed by analyzing the rate-distortion-complexity (RDC) of the VVC block structure and coding tools. First, VVenC was profiled to provide a breakdown of coding block distribution and coding tool utilization in it. Then, the usefulness of each VVC coding tool was analyzed for its individual impact on overall RDC performance. Finally, our findings were elevated to practical implementation guidelines: the highest coding gains come with the multi type tree (MTT) structure, adaptive loop filter (ALF), cross component linear model (CCLM), and bi-directional optical flow (BDOF) coding tools, whereas multi transform selection (MTS) and affine motion estimation are the primary candidates for complexity reduction. To the best of our knowledge, this is the first work to provide a comprehensive RDC analysis for practical VVC encoding. It can serve as a basis for practical VVC encoder implementation or optimization on various computing platforms.publishedVersionPeer reviewe

uvgVenctester: Open-Source Test Automation Framework for Comprehensive Video Encoder Benchmarking

acceptedVersionPeer reviewe

RDO Candidate Selection for Maximizing Coding Efficiency in a Practical HEVC Encoder

Peer reviewe

Open-source RTP Library for End-to-End Encrypted Real-Time Video Streaming Applications

Information security has become a key success factor for streaming media applications that are increasingly vulnerable to wiretapping, message forgery, data tampering, hacking, and other possible cyberattacks. This paper addresses the existing security risks in real-time video streaming by introducing a new security extension to our uvgRTP open-source Real-time Transport Protocol (RTP) library. The proposed solution improves content integrity and privacy by adopting Secure RTP (SRTP) and Zimmermann RTP (ZRTP) for media End-to-End Encryption (E2EE). These new security mechanisms make uvgRTP the first open-source library that supports on-the-fly encrypted AVC, HEVC, and VVC video streaming. Our performance results on Intel Core i7-4770 processor show that uvgRTP is able to transport encrypted 8K VVC video at up to 187 fps and 8K HEVC video at up to 120 fps over a 10 Gbps Local Area Network (LAN). The achieved transfer rate for encrypted HEVC video is 50% higher and latency 86% lower than the respective performance values of FFmpeg in unencrypted HEVC streaming. These top streaming speed results with state-of-the-art video codec support, advanced encryption mechanisms, and the permissive BSD license make uvgRTP an attractive solution for a broad range of commercial and academic streaming media applications.acceptedVersionPeer reviewe

Tailored AVX2 Transform Kernels for Versatile Video Coding

Transform coding tools play an integral part in video codecs due to their substantial impact on coding efficiency. The latest video coding standard, Versatile Video Coding (VVC), makes the most of these tools by introducing new DST7, DCT8, and non-square transforms alongside the conventional DCT2 transform. This paper proposes optimized AVX2 kernels for all these transforms to speed up VVC coding. Unlike existing solutions, our kernels are specially tailored for each VVC transform type and block size. Accelerating our open-source uvg266 VVC encoder with the proposed kernels yields up to a 1.1× speedup under all intra (AI) coding condition without any coding overhead. Our implementations make forward DCT2 and DST7/DCT8 transforms 4.0× and 6.7× as fast as their respective scalar implementations in the VTM reference encoder. They also outpace the AVX2 kernels of the practical VVenC encoder by factors of 3.0× and 2.8×. The respective speedups rise up to 5.3×, 11.1×, 3.4×, and 3.0× with inverse transforms.Peer reviewe

uvgRTP 2.0: Open-Source RTP Library For Real-Time VVC/HEVC Streaming

Real-time video transport plays a central role in various interactive and streaming media applications. This paper presents a new release of our open-source Real-time Transport Protocol (RTP) library called uvgRTP (github.com/ultravideo/uvgRTP) that is designed for economic video and audio transmission in real time. It is the first public library that comes with built-in support for modern VVC, HEVC, and AVC video codecs and Opus audio codec. It can also be tailored to diversified media formats with an easy-to-use generic API. According to our experiments, uvgRTP can stream 8K VVC video at 300 fps with an average round-trip latency of 4.9 ms over a 10 Gbit link. This cross-platform library can be run on Windows and Linux operating systems and the permissive BSD 2-Clause license makes it accessible to a broad range of commercial and academic streaming media applications.acceptedVersionPeer reviewe

Escherichia coli population structure and antibiotic resistance at a buffalo/cattle interface in Southern Africa

At a human/livestock/wildlife interface, Escherichia coli populations were used to assess the risk of bacterial and antibiotic resistance dissemination between hosts. We used phenotypic and genotypic characterization techniques to describe the structure and the level of antibiotic resistance of E. coli commensal populations and the resistant Enterobacteriaceae carriage of sympatric African buffalo (Syncerus caffer caffer) and cattle populations characterized by their contact patterns in the southern part of Hwange ecosystem in Zimbabwe. Our results (i) confirmed our assumption that buffalo and cattle share similar phylogroup profiles, dominated by B1 (44.5%) and E (29.0%) phylogroups, with some variability in A phylogroup presence (from 1.9 to 12%); (ii) identified a significant gradient of antibiotic resistance from isolated buffalo to buffalo in contact with cattle and cattle populations expressed as the Murray score among Enterobacteriaceae (0.146, 0.258, and 0.340, respectively) and as the presence of tetracycline-, trimethoprim-, and amoxicillin-resistant subdominant E. coli strains (0, 5.7, and 38%, respectively); (iii) evidenced the dissemination of tetracycline, trimethoprim, and amoxicillin resistance genes (tet, dfrA, and blaTEM-1) in 26 isolated subdominant E. coli strains between nearby buffalo and cattle populations, that led us (iv) to hypothesize the role of the human/animal interface in the dissemination of genetic material from human to cattle and toward wildlife. The study of antibiotic resistance dissemination in multihost systems and at anthropized/natural interface is necessary to better understand and mitigate its multiple threats. These results also contribute to attempts aiming at using E. coli as a tool for the identification of pathogen transmission pathway in multihost systems. (Résumé d'auteur

Efficient Topology Coding and Payload Partitioning Techniques for Neural Network Compression (NNC) Standard

A Neural Network Compression (NNC) standard aims to define a set of coding tools for efficient compression and transmission of neural networks. This paper addresses the high-level syntax (HLS) of NNC and proposes three HLS techniques for network topology coding and payload partitioning. Our first technique provides an efficient way to code prune topology information. It removes redundancy in the bitmask and thereby improves coding efficiency by 4–‍99% over existing approaches. The second technique processes bitmasks in larger chunks instead of one bit at a time. It is shown to reduce computational complexity of NNC encoding by 63% and NNC decoding by 82%. Our third technique makes use of partial data counters to partition an NNC bitstream into uniformly sized units for more efficient data transmission. Even though the smaller partition sizes introduce some overhead, our network simulations show better throughput due to lower packet retransmission rates. To our knowledge, this the first work to address the practical implementation aspects of HLS. The proposed techniques can be seen as key enabling factors for efficient adaptation and economical deployment of the NNC standard in a plurality of next-generation industrial and academic applications.acceptedVersionPeer reviewe

Escherichia coli population structure and antibioresistance at a buffalo/cattle interface in Southern Africa

At a human/livestock/wildlife interface, Escherichia coli populations were used to assess the risk of bacteria and antibioresistance dissemination between hosts. We used phenotypic and genotypic characterization techniques to describe the structure and the level of antibioresistance of E. coli commensal populations and the resistant Enterobacteriaceae carriage of sympatric African buffalo (Syncerus caffer) and cattle populations characterized by their contact patterns in the southern part of Hwange ecosystem in Zimbabwe. Our results 1) confirmed our assumption that buffalo and cattle share similar phylogroup profiles, 2) identified a significant gradient of antibioresistance from isolated buffalo to buffalo in contact with cattle and cattle populations; 3) evidenced the dissemination of tetracycline, trimethoprim and amoxicillin resistance genes (tet, dfrA, blaTEM-1in 26 isolated sub-dominant E. coli strains between nearby buffalo and cattle populations that led us 4) to hypothesize the role of the human/animal interface in the dissemination of genetic material from human to cattle and towards wildlife. The study of antibiotic resistance dissemination in multi-host systems and at anthropised/natural interface is necessary to better understand and mitigate its multiple threats. These results also contribute to attempts aiming at using E. coli as a tool for the identification of pathogen transmission pathway in multi-host systems. (Texte intégral