TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI

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CTS-Flag: Indicates whether the CTS-delta field is present. A value of 1 indicates that the field is present, a value of 0 that it is not present. CTS-Delta: Encodes the CTS by specifying the value of CTS as a 2's complement offset (delta) from the timestamp in the RTP header of this RTP packet. The CTS must use the same clock rate as the time stamp in the RTP header. DTS-Flag: Indicates whether the DTS-delta field is present. A value of 1 indicates that the field is present, a value of 0 that it is not present. DTS-Delta: specifies the value of the DTS as a 2's complement offset (delta) from the CTS timestamp. The DTS must use the same clock rate as the time stamp in the RTP header. We propose to signal each RTP payload configuration through SDP messages at the RTP session initialization. Optional fields AU Size Index /IndexDelta CTS-Flag CTS-Delta DTS-Flag DTS-Delta Figure 4-14: AU header’s fields. 4.2.2.3 Unequal Error Protection Error resilience of each Elementary Stream associated to one AVO can be enhanced when the sensitive data is protected whereas the less important data is none or less protected, as shown in, [103], [104], [105], [106], [107]. The IETF draft [108] and [109] specify how error protection is unequally applied to different part of the video stream. We extend this idea in case of object based coding (i.e. MPEG-4 AVO). To this effect, the classification layer specifies how to assign priority score to each Access Units (AU) within an AVO. From such classification, an unequal error protection (UEP) mechanism can be performed through forward error correction. 4.2.2.3.1 Reed-Solomon Codes The aim of Reed-Solomon (RS) codes is to produce at the sender n blocks of encoded data from k blocks of source data in such a way that any subset of k encoded blocks suffices at the receiver to reconstruct the source data [102]. RS code is called an (n, k) code. RS code (n, k) is defined over the Galois Field GF(2 q ) where each block contains q bits. The codeword length n is restricted by n ≤ 2 q – 1. We choose q to be 8 bits and therefore n ≤ 255. With this value for q, encoding and decoding are processed easier. Let x = x 0 … x k-1 be the source data, G an (n × k) generator matrix of the (n, k) RS code, and y the encoded data. Then, y is given by: y = G ⋅ x (Eq.1) G consists of two parts. The first part is the (k×k) identity matrix I k . The second part is an (h×h) matrix, with h=n-k. G is given by Eq.2. 84
When G is used as generator matrix, the blocks of encoded data include a verbatim copy of the source. It simplifies the reconstruction of source data when few losses are expected. ⎡1 ⎢ ⎢ 0 ⎢M ⎢ ⎢M G = ⎢0 ⎢ ⎢( n −1) ⎢( n −1) ⎢ ⎢ M ⎢ ⎣( n −1) 1 2 h 0 1 O K ( n − 2) ( n − 2) ... ( n − 2) 1 2 h K O 1 0 K ... ... ... 0 ⎤ M ⎥ ⎥ M ⎥ ⎥ 0 ⎥ 1 ⎥ ⎥ 1 ( n − h) ⎥ 2 ( n − h) ⎥ ⎥ M ⎥ h ( n − h) ⎥ ⎦ (Eq.2) 4.2.2.3.2 Unequal Error Protection Using Dynamic RS Code We propose an Unequal Error Protection (UEP) in order to handle each Access Unit according to its importance. Let us consider U , i the i th Access Unit in the flow of priority score p. The main block of the proposed UEP is to determine the values n i and k i in such a way that the (n i , k i ) RS code is efficient. The value k i is defined as the number of packets in which U i is broken when no error protection is performed. The value n i depends on the priority score p. It depends also on the length m i of U i because the traffic overhead introduced by redundant data does not become excessive. Once the efficient (n i , k ) i RS code is found, the coding step begins. We also investigate a packetization method known as block of packets which was introduced in [168]. Data of U i is placed in k i horizontal packets (S 1 , S 2 … S k ). Each packet has the same size of t i bytes. Padding is added to the last packet if m i is not a multiple of k . i Then the (n i , k ) i RS code is applied across these packets, vertically. Figure 4-15: illustrates this technique. We generate h i =n i -k i redundant packets (R 1 , R 2 …R hi ). After appending the RS codes, result packets are transmitted horizontally with a FEC header. Finally, the packet can be transmitted over a transport protocol such as Real-Time Protocol (RTP) [110]. U i S 1 S 2 S k t i bytes t i bytes t i bytes 1 byte k packets embedded original data h packets embedded redundant data S 1 S 2 S k R 1 R h Redundancy computation Figure 4-15: <strong>Packet</strong>ization mechanism FEC header contains both of the Ui sequence number and the values n i and k i of the RS code. In case of packet losses, the decoder needs this information to decode correctly the received 85
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UNIVERSITÉ DE VERSAILLES SAINT-QUE
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Résumé Nous constatons aujourd’
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3 Related Work ....................
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5.5.1.2 Simulation Results.........
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List of Figures Figure 1-1: Structu
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Figure 5-15: End-to-end packet tran
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Acknowledgments The first person I
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[11] Toufik Ahmed, Guillaume Burida
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d’accès. Les interactions de QoS
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Métrique MAX_DELAY PREF_MAX_DELAY
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1.1.2 Proposition dun Protocole d'E
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des paquets RTP. Reste toujours le
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Nous pouvons distinguer trois possi
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1.1.2.5.2 Multiplexage des Flux El
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l’horloge est par défaut égale
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La valeur R TCP représente le déb
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Pour ces raisons, nous nous intére
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Telles que illustrés par la Figure
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3. DMIF2SIP vérifie si son propre
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utilisée optionnellement pour loca
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Chapter 2 2 Introduction 2.1 Motiva
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conditions. Based on end-to-end fee
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Chapter 3 3 Related Work Nowadays,
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• multicasting: it takes the stre
Page 50 and 51: expensive, fixed delivery and recep
Page 52 and 53: 3.1.6 Static vs. Dynamic Channels T
Page 54 and 55: environment because they require a
Page 56 and 57: H.261 is called video codec for aud
Page 58 and 59: VideoScene (VS) VideoObject (VO) Vi
Page 60 and 61: The emphasis of MPEG-7 will be the
Page 62 and 63: Temporal scalability involves parti
Page 64 and 65: multitude of streams. It can switch
Page 66 and 67: increased linearly in the absence o
Page 68 and 69: 3.2.2.1 End-to-End Retransmission R
Page 70 and 71: correctly received block. The missi
Page 72 and 73: epresent user traffic. The delay ca
Page 74 and 75: 3.2.5 IP Signaling Protocols for Pa
Page 76 and 77: two H.323 endpoints or between an e
Page 79 and 80: Chapter 4 4 Adaptive Packet Video T
Page 81 and 82: 4.1.1 Video Classification Model Pr
Page 83 and 84: attributes can refer to the QoS par
Page 85 and 86: In RBF, 2 D = X − is the distance
Page 87 and 88: Figure 4-6: Experiment testbed In t
Page 89 and 90: 190 180 170 End-to-end delay MPEG-4
Page 91 and 92: Sync Layer. The SL-packetized strea
Page 93 and 94: conveyed by MIME format parameters
Page 95 and 96: the same value. This timing informa
Page 97 and 98: 4.2.2.1 Fragmentation We propose to
Page 99: Timestamp: Indicates the sampling i
Page 103 and 104: 4.2.3 Performance Evaluation Intens
Page 105 and 106: 0.3 0.25 our proposal classical app
Page 107 and 108: lost packet at the receiver. Conseq
Page 109 and 110: marking scheme. The server must be
Page 111 and 112: The video server adds audio-visual
Page 113 and 114: Marker (TR3CM) [131] to mark the ba
Page 115 and 116: VO1 VO2 AVO Scenario Audio BL EL1 E
Page 117 and 118: Throughput (Kbits) 3000 2500 2000 1
Page 119 and 120: Throughput (Kbits) 3000 2500 2000 1
Page 121 and 122: 4000 3500 3000 2500 2000 1500 1000
Page 123 and 124: 45 40 Original Quality Received Qua
Page 125 and 126: Chapter 5 5 A Dynamic Packet Video
Page 127 and 128: The TCM algorithm is based on a tok
Page 129 and 130: BEGIN Initialize the classification
Page 131 and 132: User Profile (Token Bucket) Traffic
Page 133 and 134: 5.3.3 QoS Management Algorithm Spec
Page 135 and 136: Figure 5-7: Hierarchical aggregatio
Page 137 and 138: • Filters: to put packets into cl
Page 139 and 140: mechanism associated with the Drop
Page 141 and 142: Figure 5-16: Packets loss with IP D
Page 143 and 144: 5.5.2.3 Experimental Results Figure
Page 145 and 146: 1 MPEG-4 Based Layer Stream -AF11 M
Page 147 and 148: 0.2 0.18 MPEG-4 Based Layer Stream
Page 149 and 150: By using our PBNM tool, we allocate
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Id Condition Indicator Action 1 Net
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The proposed marking algorithm bett
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Chapter 6 6 A SIP/MPEG-4 Multimedia
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performed by many ways like SLA (Se
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6.1.1.4 SIP Communication Model SIP
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• It assign a value (network sess
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6.2.1 SIP2DMIF Subsystem The SIP2DM
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Step 1: The MPEG-4 Terminal passes
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1. Set the result C to the empty se
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TCP/UDP port, our implementation us
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Control & Data Plan Video Rate Cont
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characteristics and relevance of ea
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References [1] Kazaa Media Desktop
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[43] B. Schuster, “Fine granular
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[79] D. Bansal and H. Balakrishnan,
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[115] N. Laoutaris, I. Stavrakakis,
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[154] W. Almesberger, J. H. Salim,
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Appendix A A Appendix A: Overview o
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Media aware Delivery unaware ISO/IE
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A.3.3 Scene Description Streams Sce
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This appendix presents structure ex
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