W. Tawbi, F. Horn, E. Horlait, J.B. Stefani, Video Compression Standards and Quality of Service, The Computer Journal (1993) Vol. 36. N.1, pp. 43-54.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... the variety of requirements that characterizes the DMMAs in general, and the critical DMMAs in particular, is much wider than that mentioned above; for example, these applications may well exhibit requirements for security, efficient information storage, sharing and retrieval (see, for example, [2, 8, 10, 11, 34, 36, 37, 54, 56, 60]) However, for the purposes of our discussion, we shall focus on the design, implementation, and performance evaluation of communication services that i) respond to the DMMAs scalability requirement, and provide support for the implementation of ii) reliable synchronization and isochronous ....

W. Tawbi, F. Horn, E. Horlait, J.B. Stefani, Video Compression Standards and Quality of Service, The Computer Journal (1993) Vol. 36. N.1, pp. 43-54.

....to specific applications and application areas. e.g. in the area of telecommunications, the term quality is reduced to quality of service (QoS) in which QoS is defined as the collective effect of service performance which determines the degree of satisfaction of a user of the service [3]. In [4] the QoS parameters for video conferencing are summarised as follows: Good QoS for each type of information: good picture quality, good sound, fast time respond, no transmission problems, There is no definition or evaluation of what good is. Therefore, the term 3 quality has to ....

Tawbi W., et.al., Video Compression Standards and Quality of Service, The Computer Journal, Vol.36, No.1, 1993

....of a media stream and this reduction usually has a negative impact on the quality of the delivered media stream. Alternately increasing and decreasing the media bit rate may also affect the perception of the conference quality. Unfortunately, although some have suggested measures for video quality [107] and perceptual studies have been done on video coding quality [113] we are aware of no work that compares the effect of dynamic changes in media fidelity on perceived conference quality. It is likely that changes in media fidelity have a negative effect on conference quality, but it is important ....

Tawbi, W., Horn, F., Horlait, E., Stefani, B., Video Compression Standards and Quality of Service, The Computer Journal, vol. 36, no. 1, 1989, pp. 4354.

....View of Quality [SMPT 84] or Quality of Service . In the area of telecommunications, the term quality is reduced to quality of service (QoS) in which QoS is defined as the collective effect of service performance which determines the degree of satisfaction of a user of the service [THHS 93] These definitions and explanations are very general and restricted to specific applications and application areas. As an example, RACE 93] summarizes the QoS 3 parameters for video conferencing as follows: Good QoS for each type of information: good picture quality, good sound, fast time ....

Tawbi W., et.al., Video Compression Standards and Quality of Service, The Computer Journal, Vol.36, No.1, 1993

....of data associated with continuous media, especially video, underlying systems should support a high data rate to support MM applications requirements ( Video demands on bandwidth range from Kbit s, where ranges from 1 to 30, for ISDN video phones to 1. 2 Gbits for High Definition TV (HDTV) Tawbi 93] Data rates are usually reduced using compression, but this reduces flexibility, and introduces additional latency. A number of compression techniques and standards are available, However even compressed video, still requires high bandwidth. The high bandwidth of continuous media means that ....

W. Tawbi, F. Horn, E. Horlait and J. Stefani, Video Compression Standards and Quality of Service, The Computer Journal, Vol. 36, No. 1, 1993

....the synchronization between the MPEG stream and the other streams. The important parameters induced by a particular coding scheme are: the throughput, the nature of the bit stream (variable or constant) the compression decompression delay and jitter bounds, and the structure of the stream [17] . The network transmission bit error rate and delay jitter also have an impact on the coded stream and may lead to quality degradation of the decoded data. We must consider the decoder s capability to adapt to the degradation of its input stream and apply the necessary corrective measures. 3.1 ....

W. Tawbi, F. Horn, E. Horlait and J.-B. Stefani, "Video Compression Standards and Quality of Service", The Computer Journal, Vol. 36, No. 1, 1993.

....data associated with continuous media, especially video, underlying systems should support a high data rate to support MM applications requirements (Table 1) Video demands on bandwidth range from Kbit s, where ranges from 1 to 30, for ISDN video phones to 1. 2 Gbits for High Definition TV (HDTV) Tawbi 93] Data rates are usually reduced using compression, but this reduces flexibility, and introduces additional latency. A number of compression techniques and standards are available, However even compressed video, still requires high bandwidth. The high bandwidth of continuous media means that ....

W. Tawbi, F. Horn, E. Horlait and J. Stefani, Video Compression Standards and Quality of Service, The Computer Journal, Vol. 36, No. 1, 1993

....wide geographical distances, and manage a possibly very large number of both logical and physical resources. In this context, we address those issues related to the provision of reliable distributed multimedia services. In order to provide effectively those services, recent research efforts (e.g. [2, 4, 6, 5, 21, 23, 24, 27, 33, 34, 38]) have identified a variety of requirements, including: 1. adequate abstract models of continuous data, such as digital audio and video [2, 23, 24] 2. specifying and dynamically changing the Quality Of Service (QOS) in continuous media communications [4, 21, 34] 3. an extensive range of real ....

....(e.g. 2, 4, 6, 5, 21, 23, 24, 27, 33, 34, 38] have identified a variety of requirements, including: 1. adequate abstract models of continuous data, such as digital audio and video [2, 23, 24] 2. specifying and dynamically changing the Quality Of Service (QOS) in continuous media communications [4, 21, 34]; 3. an extensive range of real time synchronization mechanisms [5, 6, 27] 4. group communication support [33, 38] The requirements 1 and 2 above are discussed at length in the already cited refences; this paper describes mechanisms designed to meet the requirements 3 and 4. The motivation for ....

W. Tawbi, F. Horn, E. Horlait, J.B. Stefani, Video Compression Standards and Quality of Service, The Computer Journal (1993) Vol. 36. N.1, pp. 43-54.

....the synchronization between the MPEG stream and the other streams. The important parameters induced by a particular coding scheme are: the throughput, the nature of the bit stream (variable or constant) the compression decompression delay and jitter bounds, and the structure of the stream [19] . The network transmission bit error rate and delay jitter also have an impact on the coded stream and may lead to quality degradation of the decoded data. We must consider the decoder s capability to adapt to the degradation of its input stream and apply the necessary corrective measures. 4.1 ....

W. Tawbi, F. Horn, E. Horlait and J.-B. Stefani, "Video Compression Standards and Quality of Service", The Computer Journal, Vol. 36, No. 1, 1993.

....underlying information infrastructure, b) model(s) that can predict QoS needs of the user application subsystem, and (c) an appropriately flexible and adaptive mechanism that can respond to these predictions either 2 MPEG codecs as well as H.120 and H. 261 should respect a delay less than 150ms [16] through dynamic negotiations with the underlying infrastructure or through dynamic adaptation of the application s own QoS needs (e.g. use of delivery modes that are less demanding of the quality or resource that cannot be met) Of course, there are difficulties associated with the delivery of ....

W Tawbi, F Horn, E Horlait, and J.B. Stefani. Video Compression Standards and Quality of Service. The Computer Journal, 36(1):43--54, January 1993.

....Importance Oriented Hybrid (JPEG, MPEG, Motion compensated Vector Scalar Subband Figure 1. Synopsis of prevailing coding techniques. runs at 30 frames per second and does not use differential coding technique. JPEG can achieve a lossless compression ratio of 50:1. Figure 1, taken from [6] and [26], gives a synopsis of the prevailing coding techniques. Table 2. Examples of video object throughput requirements Data Type Data Rate (per sec. Digitized Audio 640 Kbits PAL Digitized Video 30 Mbytes MPEG I Video 1.5 Mbits to 3.0 Mbits MPEG II Video 3.0 Mbits to 6.0 Mbits NTSC Digitized Video ....

W. Twabi, F. Horn, E. Horlatt and J. Stefani, "Video Compressions Standards and Quality of Service", The Computer Journal, 36(1):43-54, 1993.

....View of Quality [SMPT 84] or Quality of Service . In the area of telecommunications, the term quality is reduced to quality of service (QoS) in which 3 QoS is defined as the collective effect of service performance which determines the degree of satisfaction of a user of the service [THHS 93] These definitions and explanations are very general and restricted to specific applications and application areas. As an example, RACE 93] summarizes the QoS parameters for videoconferencing as follows: Good QoS for each type of information: good picture quality, good sound, fast time ....

Tawbi W., et.al., Video Compression Standards and Quality of Service, The Computer Journal, Vol.36, No.1, 1993

....adequate fault tolerance mechanisms [23] that cope effectively with the critical nature of those applications. Indeed, the variety of requirements that characterizes the DMMAs in general, and the critical DMMAs in particular, is much wider than that mentioned above, as discussed at length in [2, 6, 7, 8, 27, 29, 30, 34, 41, 43, 47], for example. However, for the purposes of this paper, we shall focus on the design of algorithms that respond to the DMMAs scalability requirement, and provide support for the implementation of i) reliable synchronization mechanisms of multimedia data streams for use from critical DMMAs,and ii) ....

Tawbi W, Horn F, Horlait E, Stefani JB (1993) Video Compression Standards and Quality of Service. The Computer Journal, Vol. 36, N. 1, pp. 43-54. UBLCS-95-10 A Appendix

....data associated with continuous media, especially video, underlying systems should support a high data rate to support MM applications requirements (Table 1) Video demands on bandwidth range from Kbit s, where ranges from 1 to 30, for ISDN video phones to 1. 2 Gbits for High Definition TV (HDTV) Taw 93] Data rates are usually reduced using compression, but this reduces flexibility, and introduces additional latency. A number of compression techniques and standards are available, However even compressed video, still requires high bandwidth. The high bandwidth of continuous media means that ....

W.Tawbi, F.Horn, E.Horlait and J.B.Stefani, Video Compression Standards and Quality of Service, The Computer Journal, Vol. 36, No. 1, 1993

....extremely tight latency requirements of around 1 ms. Other continuous media types produce large data rates. CD quality audio, for example, generates samples at rates of around 1.5 Mb s. Video exacerbates the demands by requiring data rates of about 1. 2 Mb s for MPEG compressed, VHS quality video [25], 20 Mb s for compressed HDTV, up to 200 Mb s for 24 bit (RGB) uncompressed video at 30 frames s (640 by 480 pixels) or 1.2 Gb s for uncompressed HDTV. While networks and file servers will rarely carry uncompressed video, operating systems may have to handle these if decompression is done in ....

W. Tawbi, F. Horn, E. Horlait, and J.-B. St efani, "Video compression standards and quality of service," Computer Journal, vol. 36, pp. 43--54, Feb. 1994.

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W. Tawbi, F. Horn, E. Horlait and J.-B. Stefani, "Video Compression Standards and Quality of Service", The Computer Journal, vol. 36, no. 1, 1993.

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