Binomial Bit-Rate Computation Model Based on Wireless Channel

2012 ◽  
Vol 241-244 ◽  
pp. 2482-2486
Author(s):  
Wei Ming Yang ◽  
Jian Zhang ◽  
Jin Xiang Peng
Keyword(s):  
Solution Method ◽  
Rate Distortion ◽  
Wireless Channel ◽  
Video Communication ◽  
Bit Allocation ◽  
Bit Rate ◽  
Computation Model ◽  
Refresh Rate ◽  
Network Bandwidth ◽  
Inter Frame

For the encoding bit-rate problem in H.264 wireless video communication, the bit-rate computation model and the standard deviation distortion model were analyzed to establish the relation between the quantization parameter of encoding bit-rate and the intra-frame refresh rate of macroblocks, a new proposal of the coding rate thus put forward based on the general binomial computation model theory. Furthermore, this method not only can adaptively adjust the bit allocation and quantization parameters to prevent buffer from overflowing downward or upward under given network bandwidth, but also can apply the rate-distortion to perfect the solution method, control the encoding bits accurately and optimize the allocation between the inter-frame encoding macroblocks.

scholarly journals A Decoding-Complexity and Rate-Controlled Video-Coding Algorithm for HEVC

2020 ◽  
Vol 12 (7) ◽  
pp. 120 ◽  
Author(s):  
Thanuja Mallikarachchi ◽  
Dumidu Talagala ◽  
Hemantha Kodikara Arachchi ◽  
Chaminda Hewage ◽  
Anil Fernando
Keyword(s):  
Energy Use ◽  
Signal To Noise Ratio ◽  
Rate Distortion ◽  
Complexity Reduction ◽  
Energy Availability ◽  
Bit Rate ◽  
Decoding Complexity ◽  
Network Bandwidth ◽  
Mobile Consumer ◽  
The Individual

Video playback on mobile consumer electronic (CE) devices is plagued by fluctuations in the network bandwidth and by limitations in processing and energy availability at the individual devices. Seen as a potential solution, the state-of-the-art adaptive streaming mechanisms address the first aspect, yet the efficient control of the decoding-complexity and the energy use when decoding the video remain unaddressed. The quality of experience (QoE) of the end-users’ experiences, however, depends on the capability to adapt the bit streams to both these constraints (i.e., network bandwidth and device’s energy availability). As a solution, this paper proposes an encoding framework that is capable of generating video bit streams with arbitrary bit rates and decoding-complexity levels using a decoding-complexity–rate–distortion model. The proposed algorithm allocates rate and decoding-complexity levels across frames and coding tree units (CTUs) and adaptively derives the CTU-level coding parameters to achieve their imposed targets with minimal distortion. The experimental results reveal that the proposed algorithm can achieve the target bit rate and the decoding-complexity with 0.4% and 1.78% average errors, respectively, for multiple bit rate and decoding-complexity levels. The proposed algorithm also demonstrates a stable frame-wise rate and decoding-complexity control capability when achieving a decoding-complexity reduction of 10.11 (%/dB). The resultant decoding-complexity reduction translates into an overall energy-consumption reduction of up to 10.52 (%/dB) for a 1 dB peak signal-to-noise ratio (PSNR) quality loss compared to the HM 16.0 encoded bit streams.

scholarly journals Region-of-interest-based rate control scheme for high-efficiency video coding

2014 ◽  
Vol 3 ◽  
Author(s):  
Marwa Meddeb ◽  
Marco Cagnazzo ◽  
Béatrice Pesquet-Popescu
Keyword(s):  
Video Coding ◽  
Rate Control ◽  
Control Algorithm ◽  
High Efficiency ◽  
Region Of Interest ◽  
Bit Allocation ◽  
Bit Rate ◽  
High Efficiency Video Coding ◽  
Control Scheme ◽  
Rate Control Algorithm

This paper presents a novel rate control scheme designed for the newest high efficiency video coding (HEVC) standard, and aimed at enhancing the quality of regions of interest (ROI) for a videoconferencing system. It is designed to consider the different regions at both frame level and coding tree unit (CTU) level. The proposed approach allocates a higher bit rate to the region of interest while keeping the global bit rate close to the assigned target value. The ROIs, typically faces in this application, are automatically detected and each CTU is classified in a region of interest map. This binary map is given as input to the rate control algorithm and the bit allocation is made accordingly. The algorithm is tested, first, using the initial version of the controller introduced in HEVC test model (HM.10), then, extended in HM.13. In this work, we first investigate the impact of differentiated bit allocation between the two regions using a fixed bit rate ratio in intra-coded frames (I-frames) and Bidirectionally predicted frames (B-frames). Then, unit quantization parameters (QPs) are computed independently for CTUs of different regions. The proposed approach has been compared to the reference controller implemented in HM and to a ROI-based rate control algorithm initially proposed for H.264 that we adopted to HEVC and implemented in HM.9. Experimental results show that our scheme has comparable performances with the ROI-based controller proposed for H.264. It achieves accurate target bit rates and provides an improvement in region of interest quality, both in objective metrics (up to 2 dB in PSNR) and based on subjective quality evaluation.

GPU-Based MPEG-2 to Secure Scalable Video Transcoding

2014 ◽  
Vol 6 (2) ◽  
pp. 52-69
Author(s):  
Yueyun Shang ◽  
Dengpan Ye ◽  
Zhuo Wei ◽  
Yajuan Xie
Keyword(s):  
Graphics Processing Unit ◽  
Scalable Video Coding ◽  
Single Layer ◽  
Rate Distortion ◽  
Scalable Video ◽  
Processing Unit ◽  
Video Content ◽  
High Definition ◽  
Network Bandwidth ◽  
A Minor

Most of the high definition video content are still produced in a single-layer MPEG-2 format. Multiple-layers Scalable Video Coding (SVC) offers a minor penalty in rate-distortion efficiency when compared to single-layer coding MPEG-2. A scaled version of the original SVC bitstream can easily be extracted by dropping layers from the bitstream. This paper proposes a parallel transcoder from MPEG-2 to SVC video with Graphics Processing Unit (GPU), named PTSVC. The objective of the transcoder is to migrate MPEG-2 format video to SVC format video such that clients with different network bandwidth and terminal devices can seamlessly access video content. Meanwhile, the transcoded SVC videos are encrypted such that only authorized users can access corresponding SVC layers. Using various scalabilities SVC test sequences, experimental results on TM5 and JSVM indicate that PTSVC is a higher efficient transcoding system compared with previous systems and only causes little quality loss.

scholarly journals Erasure channel modelling–based secure bit allocation schemes for multipath routing in wireless sensor networks

2016 ◽  
Vol 12 (12) ◽  
pp. 155014771668360
Author(s):  
Zhenhua Yuan ◽  
Chen Chen ◽  
Ye Jin
Keyword(s):  
Energy Efficiency ◽  
Channel Model ◽  
Multipath Routing ◽  
Optimal Solution ◽  
Wireless Channel ◽  
Bit Allocation ◽  
Wireless Sensor ◽  
Routing Scheme ◽  
Erasure Channel ◽  
Binary Erasure Channel

In this article, we study secure multipath routing with energy efficiency for a wireless sensor network in the presence of eavesdroppers. We consider two objectives: (1) the multipath routing scheme for maximising the energy efficiency with security constraints and (2) the multipath routing scheme for maximising the secrecy capacity. The binary erasure channel model is adopted to describe the wireless channel states among neighbouring nodes. Based on the binary erasure channel model, the problem of multipath routing degrades to a problem of bit allocation for each path. We formulate the problems and find that the problems are both quasi-convex. For the first one, it is a linear fractional optimisation problem. The optimal solution is obtained by the Charnes–Cooper transformation. For the second one, we propose an iterative algorithm to obtain the [Formula: see text]-optimal solution. The performance analysis shows that the probability of the secure bit allocation increases along with the number of multipaths and decreases along with the number of hops per path and eavesdroppers. Simulation results are presented to illustrate the proposed algorithms.

scholarly journals Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Slavche Pejoski ◽  
Venceslav Kafedziski
Keyword(s):  
Real Time ◽  
Fading Channels ◽  
Video Transmission ◽  
Single Layer ◽  
Rate Distortion ◽  
Wireless Channel ◽  
Video Encoding ◽  
Cross Layer ◽  
Mimo Channels ◽  
Channel Errors

We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

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