Survey of Error Correction Mechanisms for Video Streaming over the Internet <s> INTRODUCTION <s> This memorandum describes RTP, the real-time transport protocol. RTP provides end-to-end network transport functions suitable for applications transmitting real-time data, such as audio, video or simulation data, over multicast or unicast network services. RTP does not address resource reservation and does not guarantee quality-of-service for real-time services. The data transport is augmented by a control protocol (RTCP) to allow monitoring of the data delivery in a manner scalable to large multicast networks, and to provide minimal control and identification functionality. RTP and RTCP are designed to be independent of the underlying transport and network layers. The protocol supports the use of RTP-level translators and mixers. <s> BIB001 </s> Survey of Error Correction Mechanisms for Video Streaming over the Internet <s> INTRODUCTION <s> The problem of error control and concealment in video communication is becoming increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks and the Internet. This paper reviews the techniques that have been developed for error control and concealment. These techniques are described in three categories according to the roles that the encoder and decoder play in the underlying approaches. Forward error concealment includes methods that add redundancy at the source end to enhance error resilience of the coded bit streams. Error concealment by postprocessing refers to operations at the decoder to recover the damaged areas based on characteristics of image and video signals. Last, interactive error concealment covers techniques that are dependent on a dialogue between the source and destination. Both current research activities and practice in international standards are covered. <s> BIB002 </s> Survey of Error Correction Mechanisms for Video Streaming over the Internet <s> INTRODUCTION <s> Due to the explosive growth of the Internet and increasing demand for multimedia information on the Web, streaming video over the Internet has received tremendous attention from academia and industry. Transmission of real-time video typically has bandwidth, delay, and loss requirements. However, the current best-effort Internet does not offer any quality of service (QoS) guarantees to streaming video. Furthermore, for video multicast, it is difficult to achieve both efficiency and flexibility. Thus, Internet streaming video poses many challenges. In this article we cover six key areas of streaming video. Specifically, we cover video compression, application-layer QoS control, continuous media distribution services, streaming servers, media synchronization mechanisms, and protocols for streaming media. For each area, we address the particular issues and review major approaches and mechanisms. We also discuss the tradeoffs of the approaches and point out future research directions. <s> BIB003 </s> Survey of Error Correction Mechanisms for Video Streaming over the Internet <s> INTRODUCTION <s> Delivering real-time video over the Internet is an important component of many Internet multimedia applications. Transmission of real-time video has bandwidth, delay, and loss requirements. However the current Internet does not offer any quality of service (QoS) guarantees to video transmission over the Internet. In addition, the heterogeneity of the networks and end systems makes it difficult to multicast Internet video in an efficient and flexible way. Thus, designing protocols and mechanisms for Internet video transmission poses many challenges. In this paper, we take a holistic approach to these challenges and present solutions from both transport and compression perspectives. With the holistic approach, we design a framework for transporting real-time Internet video, which includes two components, namely, congestion control and error control. Specifically congestion control consists of rate control, rate-adaptive encoding, and rate shaping; error control consists of forward error correction (FEC), retransmission error resilience, and error concealment. For the design of each component in the framework, we classify approaches and summarize representative research work. We point out there exists a design space which can be explored by video application designers and suggest that the synergy of both transport and compression could provide good solutions. <s> BIB004 </s> Survey of Error Correction Mechanisms for Video Streaming over the Internet <s> INTRODUCTION <s> Preface. List of Program Files. List of Laboratory Exercises. List of Algorithms. List of Figures. List of Tables. List of Boxes. PART I: INTRODUCTION AND FOUNDATIONS. 1. A Context for Error Correcting Coding. PART II: BLOCK CODES. 2. Groups and Vector Spaces. 3. Linear Block Codes. 4. Cyclic Codes, Rings, and Polynomials. 5. Rudiments of Number Theory and Algebra. 6. BCH and Reed-Solomon Codes: Designer Cyclic Codes. 7. Alternate Decoding Algorithms for Reed-Solomon Codes. 8. Other Important Block Codes. 9. Bounds on Codes. 10. Bursty Channels, Interleavers, and Concatenation. 11. Soft-Decision Decoding Algorithms. PART III: CODES ON GRAPHS. 12. Convolution Codes. 13. Trefils Coded Modulation. PART IV: INTERATIVELY DECODED CODES. 14. Turbo Codes. 15. Low-Density Parity-Check Codes. 16. Decoding Algorithms on Graphs. PART V: SPACE-TIME CODING. 17. Fading Channels and Space-Time Coding. References. Index. <s> BIB005
In a video communication system, the video is first compressed and then segmented into fixed or variable length packets and multiplexed with other types of data. Unless a dedicated link that can provide a guaranteed quality of service (QoS) is available between the source and the destination, data bits or packets may be lost or corrupted, due to either traffic congestion or link failure. A number of different types of losses may occur, depending on the particular network under consideration. For example, wired packet networks such as the Internet are afflicted by packet loss, where congestion may cause an entire packet to be discarded (lost). Packet loss can have a destructive effect on the reconstructed video which makes the presentation displeasing to human eyes. Therefore, the video transmission system designs with error control and congestion control BIB004 to minimize the packet loss in the Internet. Nevertheless the packet loss is inevitable in the Internet BIB004 [2] BIB003 . The error control mechanisms have been proposed in order to enhance the video quality in presence of packet loss. All error correcting mechanisms are based on the same basic principle: redundancy is added to information in order to correct any errors that may occur in the process of transmission  . The error control coding classified into two categories as shown in Fig., 1 . : Error correction and Error detection. Error correction is the means whereby errors which may be introduced into digital data as a result of transmission through a communication channel can be corrected based upon received data. Error correcting codes, such as parity, LDPC 1 , Reed-Solomon [5] , and Hamming codes BIB005 used by FEC to correct the error. Parity coding and Reed-Solomon coding are often recommended in (IETF) 2 and Real-Time Transport Protocol (RTP), BIB001 . Error detection is the means whereby errors can be detected based upon received information without correction. Since the packet loss causes a degradation of visual quality, error control mechanisms can be employed to overcome this problem. Error control mechanisms for video applications can be classified into four types BIB004 BIB002 ,forward error correction (FEC), retransmission, error resilience, and error concealment. As show in " Fig. 2 .". The basic idea of FEC is to add redundant packets on compressed source packet to enable error detection and correction. Redundant packets are transmitted so that the original message can be reconstructed in case the packets are lost. Retransmission mechanisms based on the receiver notifies the sender which packets were received or lost and the sender 156 | P a g e www.ijacsa.thesai.org have to resend lost packets. ARQ is example of retransmission. Error-resilient schemes are performed at both the source and the receiver side. Error-resilient deals with packet loss on the compression layer like the error concealment. These schemes try to prevent error propagation or limit the scope of the damage caused by packet losses on the compression layer by adding redundancy data at the source coding. Error Concealment is Receiver-based error, which means this method attempts to recover the lost information by estimation and interpolation without relying on additional information from the encoder. Fig.,3 ., shows error control mechanisms architecture. This paper is organized as follows: In Section 2, we present comprehensive overview of FEC. Section 3 explained the Retransmission mechanisms. Section 4, error resilient mechanisms is explained, in section 5, we explain the error concealment mechanisms. Section 6, presents review of all mechanisms, and in section 7, conclusion is presented.