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18th IEEE International Conference on Networks (ICON)

作者： Jing, Xuan Tham, Jo Yew Wang, Yu Goh, Kwong Huang Lee, Wei Siong ASTAR Inst Infocomm Res Singapore Singapore

ISBN: (纸本)9781467345231;9781467345217

This paper addresses the quantization parameter (QP) selection problem in H.264 spatially scalable video coding (SVC). For frame level rate control in SVC, it is important to have an accurate QP selection scheme such that the target bit rate of each coding layer will be achieved. In this paper, we present an adaptive rate-quantization (R-Q) model to select the appropriate QP for each inter frame in spatial enhancement layers according to the target bit rate. The proposed algorithm introduces an efficient coding complexity estimation method by taking into consideration the inter-layer dependency between different spatial layers. Based on the coding complexity information, the R-Q model parameters can be adaptively updated. Experimental results demonstrate that compared to the traditional method, the proposed method provides better estimation accuracy for bit rate in terms of target bits mismatch error and thus it is very desirable for H.264/SVC rate control applications.

关键词： rate control rate-quantization model scalable video coding (SVC)

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A JOINT CONTENT ADAPTIVE rate-quantization model AND REGION OF INTEREST INTRA CODING OF H.264/AVC

A JOINT CONTENT ADAPTIVE RATE-QUANTIZATION MODEL AND REGION ...

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IEEE International Conference on Multimedia and Expo Workshops (ICMEW)

作者： Wu, Ching-Yu Su, Po-Chyi Yeh, Chia-Hung Hsu, Hui-Chun Natl Cent Univ Dept Comp Sci & Informat Engn Taipei Taiwan Natl Sun Yat Sen Univ Dept Elect Engn Kaohsiung Taiwan

ISBN: (纸本)9781479947614

Assigning an appropriate quantization Parameter (QP) to the Intra-coded frames is important to the video coding. In this research, a content adaptive rate-quantization (R-Q) model is presented to predict the bit usage of Intra-coded frames in H. 264/AVC. The relationship between the QP of a macroblock and the block complexity is derived so that a suitable QP can be decided under a target bit-rate. Since the proposed model is built on macroblocks, Region of Interest (ROI) coding can also be achieved. By adjusting the QP value at the macroblock level, more bits can be assigned to the ROI to better maintain its perceptual quality. The experimental results show the feasibility of the proposed R-Q model.

关键词： H.264/AVC rate Control rate-quantization model ROI

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A fast and accurate characteristic-based rate-quantization model for video transmission

A fast and accurate characteristic-based rate-quantization m...

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Conference on Visual Communications and Image Processing 2007

作者： Chan, Din-Yuen Chien, Wei-Ta Chang, Chun-Yuan Chou, Cheng-Fu Lin, Ching-Ju Hu, Junn-Yen Natl Taiwan Univ Grad Inst Networking & Multimedia Taipei 10764 Taiwan Natl Chiayi Univ Dept Comp Sci & Informat Engn Chiayi Taiwan

ISBN: (纸本)9780819466211

In this paper, we analyze the limitation of p-domain based rate-quantization (R-Q) model. We find out that a characteristic-based R-Q model can be derived from rho-domain to q-domain. Experimental data show that such a characteristic-based R-Q model can provide a more accurate estimation of the actual bitrate than existing models for both frame-level and macroblock(MB)-level. In addition, a simple analysis of computational complexity of our quantization-free characteristics extraction framework shows that our model is faster than existing variance and rho- domain based R-Q models.

关键词： rate control rate-quantization model

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Improving the quality of H. 264/AVC by using a new rate-quantization model

Improving the quality of H. 264/AVC by using a new Rate-Quan...

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Conference on the Image Quality and System Performance VIII

作者： Hrarti, M. Saadane, H. Larabi, M-C. Tamtaoui, A. Aboutajdine, D. Univ Poitiers SIC Lab XLim Inst Marie & Pierre Currie BvdBP 30179-86962 Futurosc Poitiers France Univ MohamedV Fac Sci GSCM LRIT Lab Rabat Morocco Nantes Univ Polytech Sch Nantes France Natl Inst Post & Telecommun LTI Lab Rabat Morocco

ISBN: (纸本)9780819484048

rate control plays a key role in video coding standards. Its goal is to achieve a good quality at a given target bit-rate. In H.264/AVC, rate control algorithm for both Intra and Inter-frames suffers from some defects. In the Intra-frame rate control, the initial quantization parameter (QP) is mainly adjusted according to a global target bit-rate and length of GOP. This determination is inappropriate and generates errors in the whole of video sequence. For Inter coding unit (Frame or Macroblock), the use of MAD (Mean Average Differences) as a complexity measure, remains inefficient, resulting in improper QP values because the MAD handles locally images characteristics. QP miscalculations may also result from the linear prediction model which assumes similar complexity from coding unit to another. To overcome these defects, we propose in this paper, a new rate-quantization (R-Q) model resulting from extensive experiments. This latter is divided into two models. The first one is an Intra R-Q model used to determine an optimal initial quantization parameter for Intra-frames. The second one is an Inter R-Q model that aims at determining the QP of Inter coding unit according to the statistics of the previous coded ones. It does not use any complexity measure and substitutes both linear and quadratic models used in H.264/AVC rate controller. Objective and subjective simulations have been carried out using JM15.0 reference software. Compared to this latter, the global R-Q model (Intra and Inter models combined) improves the coding efficiency in terms of PSNR, objectively (up to +2.01dB), subjectively (by psychophysical experiments) and in terms of computational complexity.

关键词： H.264/AVC Standard Complexity measure rate-quantization model Inter/ Intra Frame rate control algorithm

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Content-based coding tree unit level rate-quantization model for intra-coding in high efficiency video coding standard using convolutional neural network

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JOURNAL OF ELECTRONIC IMAGING 2022年第3期31卷 033026-033026页

作者： Rahimi, Yaser Rezaei, Mehdi Jafari, Pouria Univ Sistan & Baluchestan Fac Elect & Comp Engn Zahedan Iran

In almost all video applications, a video rate control algorithm (RCA) is used by the encoder. The RCA tunes the quantization parameter (QP) to match the encoded bit rate to the available capacity of the communication channel or storage media. Conventional RCAs usually utilize a rate-quantization (R-Q) or a rate-distortion (R-D) model for rate control. A content-based R-Q model for intra coding tree units (CTUs) of the high-efficiency video coding standard is proposed. The model is a convolutional neural network that observes pixels of a CTU and its intraprediction reference pixels and it estimates required bit counts for intracoding the CTU for all QP values simultaneously. The proposed model can be easily used by any video RCA. A given RCA just selects a proper QP for which the estimated bit counts are closer to the allocated bit budget. The evaluation results show a high accuracy for the model. According to simulation results, the mean absolute normalized bit error at CTU level is 19.66% and it decreases to 6.85% at the frame level. Compared with similar networks, the proposed structure has a very low computational complexity. (C) 2022 SPIE and IS&T

关键词： coding tree unit convolutional neural network high efficiency video coding intra-prediction rate-quantization model

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A JOINT CONTENT ADAPTIVE rate-quantization model AND REGION OF INTEREST INTRA CODING OF H.264/AVC

A JOINT CONTENT ADAPTIVE RATE-QUANTIZATION MODEL AND REGION ...

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IEEE International Conference on Multimedia and Expo

作者： Ching-Yu Wu Po-Chyi Su Chia-Hung Yeh Hui-Chun Hsu Dept. of Computer Science and Information Engineering National Central University Dept. of Electrical Engineering National Sun Yat-sen University

ISBN: (纸本)9781479947607

Assigning an appropriate quantization Parameter (QP) to the Intra-coded frames is important to the video coding. In this research, a content adaptive rate-quantization (R-Q) model is presented to predict the bit usage of Intra-coded frames in H.264/AVC. The relationship between the QP of a macroblock and the block complexity is derived so that a suitable QP can be decided under a target bit-rate. Since the proposed model is built on macroblocks, Region of Interest (ROI) coding can also be achieved. By adjusting the QP value at the macroblock level, more bits can be assigned to the ROI to better maintain its perceptual quality. The experimental results show the feasibility of the proposed R-Q model.

关键词： H.264/AVC rate Control rate-quantization model ROI

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Accurate Bitrate model and Greedy-Based rate Controller for Low Delay Video Transmission

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IEEE SYSTEMS JOURNAL 2012年第3期6卷 414-425页

作者： Chang, Chun-Yuan Chou, Cheng-Fu Chan, Din-Yuen Lin, Tsungnan Chen, Ming-Hung Natl Taiwan Univ Grad Inst Networking & Multimedia Taipei 10617 Taiwan Natl Chayi Univ Dept Comp Sci & Informat Engn Chayi 10600 Taiwan Natl Taiwan Univ Grad Inst Commun Engn Taipei 10617 Taiwan Natl Taiwan Univ Dept Comp Sci & Informat Engn Taipei 10617 Taiwan

We develop a q-domain characteristic-based rate model for video transmission. Specifically, we extract three characteristics from the quantized discrete cosine transform spectra to construct an accurate rate-quantization (R-Q) model. Moreover, the extraction of the proposed characteristics requires only simple additive operations (additions, subtractions, and comparisons) and few multiplications. Based on the q-domain characteristic-based bitrate model, we develop an efficient two-level greedy-based rate controller for low delay video transmission. Extensive experimental results show that due to the efficiency and accurate estimation of both macroblock and frame-level R-Q models, the proposed rate controller better maintains the source bitrate to meet a predefined buffer delay time, and substantially enhances visual quality as compared with other rate controllers.

关键词： rate control rate-quantization model

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A Joint rate Control Scheme in a Hybrid Stereoscopic Video Codec System for 3DTV Broadcasting

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IEEE TRANSACTIONS ON BROADCASTING 2013年第2期59卷 265-280页

作者： Chang, Yongjun Kim, Munchurl Hyundai Asan Hosp Seoul 138736 South Korea Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea

In this paper, a frame-level joint rate control scheme for both intra-and inter-predictive coding is first introduced for a hybrid video codec system that independently encodes the two-view sequences of a stereoscopic video. The proposed rate control scheme jointly works on the left view encoder of MPEG-2 Video and the right view encoder of an H.264/AVC for stereoscopic video input, and is formulated as optimization problems that allow control of the output bit rates of both encoders in the sense that: 1) the sum of the two decoded video qualities is maximized, and 2) the quality difference is maintained around a desired level for a given target bit budget at the same time. In order to verify the effectiveness of the proposed joint rate scheme, it is compared with an independent rate control scheme. The experimental results show that the joint rate control scheme effectively regulates the output bitstreams of the hybrid encoders based on MPEG-2 Video and H.264/AVC. The joint rate control scheme achieves average 0.71 dB gain in PSNR and 67.07% reduction in the MSE of PSNR difference for I-frame only, average 0.54 dB gain and 91.08% reduction for IPPP coding, and average 0.32 dB gain and 79.01% reduction for IBBP coding.

关键词： Distortion-quantization model hybrid codec joint rate control optimization rate-quantization model target bit allocation

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Adaptive Initial quantization Parameter Determination for H. 264/AVC Video Transcoding

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IEEE TRANSACTIONS ON BROADCASTING 2012年第2期58卷 277-284页

作者： Wu, Zhenyu Yu, Hongyang Tang, Bin Chen, Chang Wen Univ Elect Sci & Technol China Chengdu 610054 Peoples R China SUNY Buffalo Buffalo NY 14260 USA

Video adaptation through transcoding can provide both bit-rate reduction and resolution reduction to meet various requirements from display devices to network links. One important issue in video transcoding is the design of rate control algorithm in order to achieve target bit rate by adjusting certain coding parameters. Among them, proper selection of initial quantization parameter (QP) has been shown to induce noticeable impact on the performance of video transcoding scheme. Current approaches in initialQP determination are either too complicated or lacking adequate accuracy. This paper presents an adaptive QP initialization for H.264/AVC transcoding. First, we carefully build the models of R-MSE and QP-PSNR. Then, we introduce an R-QP model and allocate an optimal target buffer to the first frame by considering its temporal importance. The analysis and the R-QP model lead to a novel scheme to determine the initial QP adaptively to achieve more accurate estimation. Experiments have been carried out to demonstrate that substantial gains in objective quality measures can be consistently obtained. Without increasing complexity in transcoding system, the proposed adaptive initial QP scheme outperforms current existing schemes for various video sequences tested in this research.

关键词： Adaptive quantization rate control rate-quantization model transcoding

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A Frame-Level rate Control Scheme Based on Texture and Nontexture rate models for High Efficiency Video Coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2014年第3期24卷 465-479页

作者： Lee, Bumshik Kim, Munchurl Nguyen, Truong Q. Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea

In this paper, a frame-level rate control scheme is proposed based on texture and nontexture rate models for High Efficiency Video Coding (HEVC). Due to more complicated coding structures and the adoption of new coding tools, the statistical characteristics of transform residues are significantly different depending on the depth levels of coding units (CUs) from which the residues are obtained. A new texture rate model is constructed for the transform residues, which are categorized into three types of CUs: low-, medium-and high-textured CUs. One single Laplacian probability PDF model is used for each residue category to derive a rate-quantization model. Based on the Laplacian PDF, a simplified rate model for texture bits is derived using entropy. In addition, an analytic rate model for nontexture bits is proposed, which also takes into account the different characteristics of nontexture bits occurring in various depths of CUs in HEVC. The nontexture bitrates are modeled based on the linear relation between the total nontexture data and the dominant nontexture data in each CU category. Based on the proposed rate models for the texture and nontexture bits, accurate rate control can be achieved owing to more precise rate estimation. The experimental results show that the proposed rate control scheme achieves the average PSNR with 0.44 dB higher and the average PSNR standard deviation of 0.32 point lower with the buffer status levels maintained very close to target buffer levels, compared to the conventional methods. Finally, the proposed rate control scheme remarkably outperforms the conventional schemes especially for the sequences of complex texture and large motion.

关键词： High Efficiency Video Coding (HEVC) Laplacian distribution rate control rate-quantization model

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