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Multi-Band Transmission Using Reconfigurable Complex Multi-Band Delta Sigma Polar Modulator

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS 2022年第1期69卷 94-98页

作者： Kumar, Nishant Rawat, Karun Ghannouchi, Fadhel M. Indian Inst Technol Roorkee Dept Elect & Commun Roorkee 247667 Uttar Pradesh India Univ Calgary iRadio Lab Dept Elect & Comp Engn Schulich Sch Engn Calgary AB T2N 1N4 Canada

This brief presents a new reconfigurable complex multi-band delta sigma polar modulator (CMB-DSPM) architecture for multi-band transmission. In this brief, a 6th order band-pass delta sigma modulator (DSM) is designed and implemented for reconfigurable triple-band transmission. The proposed DSM architecture utilizes the advantage of a complex DSM structure to reduce the required processing block and polar quantizer to reduce the quantization noise. The proposed CMB-DSPM architecture improves the in-band and out-of-band performance in terms of signal-to-noise distortion ratio (SNDR) and coding efficiency (CE), respectively. The proposed scheme is validated in MATLAB/SIMULINK-based digital signal processing platform using three 5 MHz long-term evolution (LTE) signals. The results show up to 12.4 dB improvement in SNDR and 12.3% improvement in CE compared to the standard cartesian DSM architecture. The measured EVM is below 3%, which shows the good in-band performance of the proposed scheme.

关键词： Carrier aggregation coding efficiency delta Sigma modulation multi-band transmission polar quantization

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ROFC-LF: Recursive Online Fountain Code With Limited Feedback for Underwater Acoustic Networks

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IEEE TRANSACTIONS ON COMMUNICATIONS 2022年第7期70卷 4327-4342页

作者： Liu, Xiuxiu Du, Xiujuan Zhang, Jiliang Han, Duoliang Jin, Long Qinghai Normal Univ Coll Comp Xining 810008 Peoples R China Acad Plateau Sci & Sustainabil Xining 810008 Peoples R China Qinghai Normal Univ Coll Comp Qinghai Prov Key Lab IoT Xining 810008 Peoples R China Acad Plateau Sci & Sustainabil State Key Lab Tibetan Intelligent Informat Proc & Xining 810008 Peoples R China Univ Sheffield Dept Elect & Elect Engn Sheffield S1 4DT S Yorkshire England Lanzhou Univ Sch Informat Sci & Engn Lanzhou 730000 Peoples R China

Online fountain codes (OFCs) have many advantages, such as low overhead, online feedback and optimal encoding, due to the feedback of the instantaneous decoding state. This paper analyzes the characteristics of underwater acoustic networks (UANs) as well as the issues of existing OFCs applied in UANs. Aiming at these issues, two optimization objectives of OFCs are put forward for UANs. In addition, a recursive OFC with limited feedback (ROFC-LF) is presented for UANs. The ROFC-LF reduces the consumption of bandwidth and energy caused by the transmission of useless coding packets. Through limited feedback, the problem of low channel utilization in UANs with half-duplex communication is solved. Furthermore, a data transmission mechanism based on the ROFC-LF for UANs is presented. The theoretical analysis and simulation results show that the proposed transmission mechanism based on the ROFC-LF scheme outperforms the existing OFC schemes in terms of overhead, computational complexity, coding efficiency and energy consumption. Consequently, the ROFC-LF is suitable for UANs with constrained resources.

关键词： Codes Encoding Decoding Bandwidth Receivers Optimization Half-duplex system ROFC-LF UANs overhead feedback coding efficiency computational complexity energy consumption

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Highly Efficient Audio coding With Blind Spectral Recovery Based on Machine Learning

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IEEE SIGNAL PROCESSING LETTERS 2022年 29卷 1212-1216页

作者： Kim, Jae-Won Beack, Seung Kwon Lim, Wootaek Park, Hochong Kwangwoon Univ Dept Elect Engn Seoul 01897 South Korea Elect & Telecommun Res Inst ETRI Daejeon 34129 South Korea

This letter proposes a new method for audio coding that utilizes blind spectral recovery to improve the coding efficiency without compromising performance. The proposed method transmits only a fraction of the spectral coefficients, thereby reducing the coding bit rate. Then, it recovers the remaining coefficients in the decoder using the transmitted coefficients as input. The proposed method is differentiated from conventional spectral recovery in that the coefficients to be recovered are interleaved with the transmitted coefficients to obtain the most data correlation. Further, it enhances the transmitted coefficients, which are degraded by quantization errors, to deliver better information to the recovery process. The spectral recovery is conducted recursively on a band basis such that information recovered in one band is used for the recovery in subsequent bands. An improved level correction for the recovered coefficients and a new sign coding are also developed. A subjective performance evaluation confirms that the proposed method at 40 kbps provides statistically equivalent sound quality to a state-of-the-art coding method at 48 kbps for speech and music categories.

关键词： Encoding Audio coding Decoding Quantization (signal) Correlation Bit rate Transforms Audio coding coding efficiency machine learning spectral enhancement spectral recovery

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Enhancing SVT-AV1 with LCEVC to improve quality-cycles trade-offs and enhance sustainability of VOD transcoding 45

Enhancing SVT-AV1 with LCEVC to improve quality-cycles trade...

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Applications of Digital Image Processing XLV

作者： Cobianchi, Guendalina Meardi, Guido Poularakis, Stergios Walisiewicz, Alexei Abdelkafi, Omran Ben Amara, Foued Kossentini, Faouzi Stejerean, Cosmin Tmar, Hassene V Nova Ltd 20 Eastbourne Terrace London England Intel Corp Suite 700450 SW Marine Dr Vancouver BC V5X 0C3 Canada Meta Platforms 1 Hacker Way Menlo Pk CA USA

ISBN: (纸本)9781510654372;9781510654365

The trade-offs between compression performance and encoding complexity are key in software video encoding, even more so with increasing pressure on sustainability. Previous work "Towards much better SVT-AV1 quality-cycles trade-offs for VOD applications" [1] described three approaches of evaluating compression efficiency vs cycles trade-offs within a convex-hull framework using the Dynamic Optimizer (DO) algorithm developed in [2] [3] for VOD applications. In parallel, the new video codec enhancer LCEVC (Low Complexity Enhancement Video coding) [4], designed to provide gains in speed-quality trade-offs, has recently been standardized as MPEG-5 Part 2. The core idea of LCEVC is to use any video coding standard (such as AV1) as a base encoder at a lower resolution, and then reduce artifacts and reconstruct a full resolution output by combining the decoded low-resolution output with up to two low-complexity reconstruction enhancement sub-layers of the residual data. This paper starts by applying LCEVC to SVT-AV1 [5], as well as x264 [6] and x265 [7], while using two of the approaches presented in [1] to evaluate the resulting compression efficiency vs cycles trade-offs. The paper then discusses the benefits of LCEVC towards higher playback speed and lower battery power consumption when using AV1 software decoding. Results show that, with fast-encoding parameter selection using the discrete convex hull methodology, LCEVC improves the quality-cycles trade-offs for all the tested codecs and across the full complexity range. In the case of SVT-AV1, LCEVC yields a similar to 40% reduction in computations while achieving the same quality levels according to VMAF_NEG [8]. LCEVC also enlarges the set of mobile devices capable of playing HD as well as high-frame-rate content encoded with AV1 and extends mobile battery life by up to 50% with respect to state-of-the-art AV1 software decoding.

关键词： AV1 SVT-AV1 Low Complexity Enhancement Video coding (LCEVC) MPEG-5 Part 2 video compression video coding standard enhancement software codec multi-resolution video coding multi-layer encoding convex hull dynamic optimizer encoder complexity coding efficiency adaptive streaming

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Adaptive block tree structure for video coding

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ETRI JOURNAL 2021年第2期43卷 313-323页

作者： Baek, Aram Gwon, Daehyeok Son, Sohee Lee, Jinho Kang, Jung-Won Kim, Hui Yong Choi, Haechul Hanbat Natl Univ Dept Multimedia Engn Daejeon South Korea Elect & Telecommun Res Inst Broadcasting Media Res Grp Daejeon South Korea Kyung Hee Univ Dept Comp Sci & Engn Yongin South Korea

The Joint Video Exploration Team (JVET) has studied future video coding (FVC) technologies with a potential compression capacity that significantly exceeds that of the high-efficiency video coding (HEVC) standard. The joint exploration test model (JEM), a common platform for the exploration of FVC technologies in the JVET, employs quadtree plus binary tree block partitioning, which enhances the flexibility of coding unit partitioning. Despite significant improvement in coding efficiency for chrominance achieved by separating luminance and chrominance tree structures in I slices, this approach has intrinsic drawbacks that result in the redundancy of block partitioning data. In this paper, an adaptive tree structure correlating luminance and chrominance of single and dual trees is presented. Our proposed method resulted in an average reduction of -0.24% in the Y Bjontegaard Delta rate relative to the intracoding of JEM 6.0 common test conditions.

关键词： block structure coding efficiency quadtree plus binary tree versatile video coding video coding

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AV1 Benchmarking Test for 3GPP 45

AV1 Benchmarking Test for 3GPP

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Applications of Digital Image Processing XLV

作者： Lei, Zhijun Song, Jun Sik Grange, Adrian Han, Jingning Simmons, John Norkin, Andrey Meta Platforms Inc Menlo Pk CA 94025 USA Google LLC Mountain View CA USA Alliance Open Media Wilmington DE USA Netflix Inc Los Gatos CA USA

ISBN: (纸本)9781510654372;9781510654365

AV1 is the first-generation royalty free video coding standard developed by the Alliance for Open Media (AOM). Since it was finalized in 2018, there have been a lot of attempts to compare the compression efficiency of AV1 against previous generations of video coding standards, such as HEVC, VP9, etc. Some study results have been published previously, but the results vary significantly depending on test conditions and encoder configurations used. It is challenging to design a test configuration and align the encoding parameters to perform a benchmarking test between coding standards and their encoder implementations. Recently, 3GPP started an exploration project to evaluate next generation video coding standards, after AVC and HEVC, for consideration in future 3GPP standards and applications. In this project, a comprehensive set of test conditions was defined to compare the submitted coding specifications, including AV1, VVC, and EVC, versus HEVC and AVC. The evaluation was conducted using reference encoders for each specification. The reference encoders of each proposed coding specification were thoroughly tested using the defined test condition set to provide benchmarking data that could be used in their evaluation and possible inclusion for future 5G streaming services. In this paper, we will first discuss the test scenarios and test configurations for the 3GPP benchmarking test. Then, the detailed encoding parameters for the AV1 reference encoder, which comply with this set of test conditions, will be introduced and the benchmarking test result will be presented. Finally, we will introduce some encoding settings that can be applied to the AV1 reference encoder without some HM and VTM inspired restrictions defined in the test 3GPP test conditions and the corresponding compression efficiency improvement that can be achieved in the expected AV1 usage.

关键词： AV1 Video compression coding efficiency AVC HEVC EVC VVC 3GPP

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An Efficient Video coding System With an Adaptive Overfitted Multi-Scale Attention Network

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IEEE ACCESS 2021年 9卷 64022-64032页

作者： He, Gang Wu, Chang Xu, Li Li, Lei Xu, Ziyao Xie, Weiying Li, Yunsong Xidian Univ Sch Telecommun Engn State Key Lab Integrated Serv Networks Xian 710071 Peoples R China

We herein propose an efficient video coding system (EVCS) consists of a conventional codec and an adaptive overfitted multi-scale attention network (MSAN) to improve coding efficiency. At the encoder side, the MSAN adjusts the network size adaptively and is trained in an overfitting way for a group of frames. Using only the current encoding video stream as a training set, the MSAN can easily obtain powerful restoration capability. After training, the learned parameters of the MSAN are transmitted to the decoder as part of the encoded bitstream. At the decoder side, the MSAN loaded with the transmitted parameters can restore the reconstructed frames very meticulously. Compared with the high efficiency video coding (HEVC) standard, the EVCS can achieve 12.141% Bjontegaard-Delta bitrate reduction, which outperforms existing deep learning based compressed video restoration works with less computation complexity. Moreover, the MSAN is an additional part of the conventional codec without any structure change, thereby rendering it compatible with the existing coding systems.

关键词： Decoding Video coding Training Image restoration Feature extraction Neural networks Image coding Video compression overfitting deep neural network coding efficiency quality improvement

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LEARNED IMAGE COMPRESSION WITH CHANNEL-WISE GROUPED CONTEXT MODELING

LEARNED IMAGE COMPRESSION WITH CHANNEL-WISE GROUPED CONTEXT ...

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IEEE International Conference on Image Processing (ICIP)

作者： Yuan, Liang Luo, Jixiang Li, Shaohui Dai, Wenrui Li, Chenglin Zou, Junni Xiong, Hongkai Shanghai Jiao Tong Univ Sch Elect Informat & Elect Engn Shanghai Peoples R China

ISBN: (纸本)9781665441155

Learned image compression has achieved improved rate-distortion performance with end-to-end optimized framework based on deep neural networks. However, context-based entropy modeling for learned image compression cannot simultaneously achieve enhanced efficiency and sufficiently exploiting the channel-wise correlations. In this paper, we propose a novel framework for learned image compression with channel-wise grouped context modeling. The proposed framework presents channel-wise grouping to explicitly exploit the channel-wise correlations and develop a grouped 3-D context model to achieve efficient entropy coding with a guarantee of rate-distortion performance. The proposed framework achieves competitive performance with a significantly reduced decoding complexity in comparison to 3-D context models.

关键词： Image compression entropy modeling spectral clustering coding efficiency

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Towards Much Better SVT-AV1 Quality-Cycles Tradeoffs for VOD Applications 44

Towards Much Better SVT-AV1 Quality-Cycles Tradeoffs for VOD...

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Conference Applications of Digital Image Processing XLIV

作者： Wu, Ping-Hao Katsavounidis, Ioannis Lei, Ryan Ronca, David Tmar, Hassene Abdelkafi, Omran Cheung, Colton Ben Amara, Foued Kossentini, Faouzi Facebook Menlo Pk CA USA Intel Corp Suite 700450 SW Marine Dr Vancouver BC V5X 0C3 Canada

ISBN: (数字)9781510645233

ISBN: (纸本)9781510645233;9781510645226

Software video encoders that have been developed based on the AVC, HEVC, VP9, and AV1 video coding standards have provided improved compression efficiency but at the cost of large increases in encoding complexity. As a result, there is currently no software video encoder that provides competitive quality-cycles tradeoffs extending from the AV1 high-quality range to the AVC low-complexity range. This paper describes methods to further improve the SVT-AV1 overall quality-cycles tradeoffs for high-latency VOD applications. The paper first presents the latest SVT-AV1 encoder evaluation results generated using the conventional convex-hull-based evaluation approach. To better account for all the content being considered in the evaluation, the combined convex hull approach is then introduced and corresponding results outlined. A more practical version of the latter approach, referred to as the restricted discrete approach, is then presented. In this approach, only few discrete quality levels that are of relevance to typical adaptive streaming applications are considered. This restriction makes the evaluation data more relevant to real adaptive streaming applications and reduces the storage requirements for the encodings generated at the identified optimal encoder settings. A fast version of the latter approach is then presented, where the generation of the optimal encoder parameters is performed using a fast encoder, and the final encodings needed in the evaluation are generated using the desired encoder based on the identified optimal encoder parameters. These optimizations result in a complexity reduction by up to a factor of 10 for at most 1.5% loss in BD-rate.

关键词： AV1 SVT-AV1 Video compression coding efficiency Adaptive streaming Convex hull Dynamic optimizer Encoder complexity

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Machine learning based tuning of encoding parameters for UGC video coding optimizations 44

Machine learning based tuning of encoding parameters for UGC...

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Conference Applications of Digital Image Processing XLIV

作者： Chaudhari, Gaurang Koba, Igor Katsavounidis, Ioannis Reddy, Harikrishna Tescher, Andrew G. Ebrahimi, Touradj Facebook Inc 1 Hacker Way Menlo Pk CA 94025 USA

ISBN: (数字)9781510645233

ISBN: (纸本)9781510645233;9781510645226

In the era of COVID-19 pandemic, videos are very important to the billions of people staying and working at home. Two-pass video encoding allows for a refinement of parameters based on statistics obtained from the first pass. Given the variety of characteristics in user-generated content, there is opportunity to make this refinement optimal for this type of content. We show how we can replace the traditional models used for rate control in video coding with better prediction models with linear and nonlinear model functions. Moreover, we can utilize these first-pass statistics to further refine the traditional encoding recipes that are typically used for all input video sequences. Our work can provide much-needed bitrate savings for many different encoders, and we highlight it by testing on typical Facebook video content.

关键词： video encoding user generated content UGC quantization parameter Qp VP9 linear regression rate control first pass statistics coding efficiency

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