Error-resilient MPEG-4 video communication over error-prone wireless networks (original) (raw)

Error resilient video coding techniques

2000

Abstract We review error resilience techniques for real-time video transport over unreliable networks. Topics covered include an introduction to today's protocol and network environments and their characteristics, encoder error resilience tools, decoder error concealment techniques, as well as techniques that require cooperation between encoder, decoder, and the network. We provide a review of general principles of these techniques as well as specific implementations adopted by the H.

Error-resilient transcoding for video over wireless channels

IEEE Journal on Selected Areas in Communications, 2000

We describe a method to maintain quality for video transported over wireless channels. The method is built on three fundamental blocks. First, we use a transcoder that injects spatial and temporal resilience into an encoded bitstream. The amount of resilience is tailored to the content of the video and the prevailing error conditions, as characterized by bit error rate. Second, we derive analytical models that characterize how corruption propagates in a video that is compressed using motion-compensated encoding and subjected to bit errors. Third, we use rate distortion theory to compute the optimal allocation of bit rate among spatial resilience, temporal resilience, and source rate. Furthermore, we use the analytical models to generate the resilience rate distortion functions that are used to compute the optimal resilience. The transcoder then injects this optimal resilience into the bitstream. Simulation results show that using a transcoder to optimally adjust the resilience improves video quality in the presence of errors while maintaining the same input bit rate.

Analysis of Video Coding and Error Resilience Tools of H. 264/AVC in Wireless Environment

International Journal of Computer Applications, 2012

Recently more and more telecommunication systems are supporting different kinds of real-time transmission, video transmission being one of the most important application.In wireless environments, channel bandwidth and high packet loss rate are to main limitations in the way of delivering of a good quality video to the end user. Therefore, in applications such as video over wireless networks, a video codec should have ability to handle the erroneous situations of the channels well as the bandwidth limitations.H.264/AVC is the newest international video coding standard, jointly developed by groups from ISO/IEC and ITUT.It has several error resilience techniques to make a video bit stream robust in the erroneous channels conditions and also achieves a significant improvement in the compression efficiency. We analyze various error resilienceschemes and innovative featuresof H.264/AVC for real time video streaming .The focus of the work is to test video coding and error resilience tools of H.264/AVC in real timeenvironment over wireless networks.

Improving the robustness of MPEG-4 video communications over wireless/3G mobile networks

The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

Two major issues in providing true end-to-end wireless/mobile video capabilities are: interoperability among network platforms and robustness of video compression algorithms in error-prone environments. In this paper, we mainly focus on the second issue and show how error resilience techniques can be used to improve the video quality. We argue that the error resilient tools provided within the MPEG-4 standard are not sufficient to provide acceptable quality in wireless/mobile networks, but that this quality can be significantly improved by the inclusion of hierarchical MPEG-4 video coding techniques. We present a novel hierarchical MPEG-4 video scheme particularly designed for video communications over QoS-capable wireless/mobile network.

Error-resilient performance evaluation of MPEG-4 and H.264

Visual Communications and Image Processing 2003, 2003

Recent advances in video coding technology have resulted in rapid growth of application in mobile communication. With this explosive growth, reliable transmission and error resilient technique become increasingly necessary to offer high quality multimedia service. This paper discusses the error resilient performances of the MPEG-4 simple profile under the H.324/M and the H.264 baseline under the IP packet networks. MPEG-4 simple profile has error resilient tools such as resynchronization marker insertion, data partitioning, and reversible VLC. H.264 baseline has the flexible macroblock ordering scheme, and others. The objective and subjective quality of decoded video is measured under various random bit and burst error conditions. Keywords: Error resilient tools, MPEG-4, H.264, video coding technology

Impact of bit error on video transmission over wireless networks and error resiliency

2011 International Conference on Image Information Processing, 2011

To improve the robustness of video transmission over heterogeneous wireless network various error resilient tools are deployed. The impact of bit errors on the perceived video quality depends on several factors, such as error resilience of the data format, error concealment mechanism used and characteristics of the bit error pattern. In this paper the impact of bit error is analyzed and various error resilient tools implemented at the transmitter side, at the receiver and the ones requiring interactive feedback on dynamic channel conditions are discussed. The paper also covers a few cross layer optimization techniques.

A Review of Error Resilience Techniques in Video Streaming

2006

Abstract—Delivering video data of satisfactory quality over unreliable networks-such as the internet or wireless networks-is a demanding area which has received significant attention of the research community over the past few years. Given the fact that packet loss is inevitable and therefore the presence of errors granted, the effort is directed towards limiting the effect of these errors. A number of techniques have been developed to address this issue.

Error-resilient video coding for wireless video telephony applications

Applications of Digital Image Processing XXXV, 2012

In this paper, we present an error resilient video coding scheme for wireless video telephony applications that uses feedback to limit error propagation. In conventional feedback-based error resilient schemes, error propagation can significantly degrade visual quality when feedback delay is in the order of a few seconds. We propose a coding structure based on multiple description coding that mitigates error propagation during feedback delay, and uses feedback to adapt its coding structure to effectively limit error propagation. We demonstrate the effectiveness of our approach at different error rates when compared to conventional coding schemes that use feedback.

Packet loss resilient MPEG-4 compliant video coding for the Internet

Signal Processing: Image Communication, 1999

Targeting multimedia communications over the Internet, this paper describes a set of complementary techniques in the direction of both improved packet loss resiliency of video-compressed streams and e$cient usage of available network resources. Aiming "rst at a best trade-o! between compression e$ciency and packet loss resiliency, a procedure for adapting the video coding modes to varying network characteristics is introduced. The coding mode selection is based on a rate-distortion procedure with global distortion metrics incorporating channel characteristics under the form of a two-state Markov model. This procedure has been incorporated in an MPEG-4 video encoder. It has been observed that, in error-free environments, the channel adaptive mode selection technique does not bring any penalty in terms of compression, with respect to the initial MPEG-4 encoder, while allowing a signi"cant gain with respect to simple conditional replenishment. On the other hand, under the same loss conditions, it is shown that this procedure signi"cantly improves the encoder's performance with respect to the original MPEG-4 encoder, to approach the robustness of conditional replenishment mechanisms. This intrinsic robusti"cation of the encoder allows to minimize the e!ects of packet losses on the visual quality of the received video; however, it does not avoid losses. A rate-based #ow control mechanism is then developed and introduced into the encoder, in order to match the bandwidth requirements of the source to the bandwidth available over the path of the connection, for both &social' and &individual' bene"ts. The control mechanism developed combines an RTT-based control loop allowing early reaction to congestion and a TCPfriendly rate prediction model getting into play under lossy conditions. This hybrid control mechanism allows full rate control (even in loss-free conditions) and smooth rate variations together with high responsiveness. The introduction of the rate control in the MPEG-4 compliant encoder allows to maintain a stable PSNR and visual quality while decreasing signi"cantly the source throughput, hence reducing congestion and loss provoked by the same video source at a constant bit-rate. (F. Le LeH annec) with respect to quality of service, congestion management, and network friendliness. Due to the real-time nature of envisioned data streams, multimedia delivery usually makes use of the so-called unresponsive transport protocols, i.e. the User Datagram Protocol (UDP) and/or Real-time Transport Protocol (RTP). Both UDP and RTP o!er no quality of service control mechanisms and can therefore not guarantee any level of QoS, 0923-5965/99/$ -see front matter 1999 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 3 -5 9 6 5 ( 9 9 ) 0 0 0 2 3 -5

Error resilience and recovery in streaming of embedded video

Signal Processing, 2002

The three-dimensional (3-D) SPIHT coder is a scalable or embedded coder that has proved its e ciency and its real-time capability in compression of video. A forward-error-correcting (FEC) channel (RCPC) code combined with a single automatic repeat request (ARQ) proved to be an e ective means for protecting the bitstream. There were two problems with this scheme: the noiseless reverse channel ARQ may not be feasible in practice; and, in the absence of channel coding and ARQ, the decoded sequence was hopelessly corrupted even for relatively clean channels. In this paper, we introduce a new method of partitioning wavelet coe cients into spatio-temporal (s-t) tree blocks to achieve error resilience. Each of these s-t blocks corresponds to the full 3-D image region, because roots of these trees are wavelet coe cients taken at ÿxed intervals in the root low-frequency subband. Previously, we reported on grouping contiguous root subband coe cients to generate s-t tree blocks that correspond to local 3-D regions. The new procedure brings higher error resilience, since lost coe cients can be concealed with the surrounding coe cients even if some of the coded s-t blocks are totally missing. The bitstreams of the coded s-t blocks are packetized and encoded with a channel code to correct errors and to prevent decoding of erroneous data after errors are detected. Because the separately encoded s-t blocks produce embedded bitstreams, the packets from the bitstreams are interleaved to generate an embedded composite bitstream. The embedded property, whereby successive compressed bits convey successively smaller value information, suggests unequal error protection, where earlier bits are more strongly protected by the channel code than later bits. Therefore, unequal error protection is also incorporated into our video bitstreams to bring an even higher degree of resilience to channel bit errors. Our claims are supported by extensive simulations with decoding of the various 3-D SPIHT bitstreams compared to each other and to MPEG-2. Superiority to MPEG-2 in noiseless and noisy channels, under equal conditions with or without FEC, is clearly demonstrated by the results of these simulations. ? 2002 Published by Elsevier Science B.V.