TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI

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environment because they require a great scalability, lower computational complexity, great resiliency to network losses and lower encoding / decoding latency. Building a video codec that response to all these requirements is not sufficient. The codec must be aware of network condition in order to achieve the highest possible user perceived quality. Current research is investigating a new scalable and flexible coding algorithm, and ways for adapting the existing codecs to heterogeneous environment such as Internet. We present in this subsection some of video codec that are widely used in packet video applications. 3.2.1.1.1 Overview of Video Compression Since Newton’s time, it has been known that a wide spectrum of colors can be generated from a set of three primaries colors. Television displays generate colors by mixing lights of the additive primaries: red, green, and blue (RGB). The classic color chart used in early television specifications was established in 1931 by the Commission Internationale de L’Eclairage (CIE). It defines a special concept of isolating the luminance, or brightness, from the chrominance, or hue. From this chart, two systems were defined, namely, NTSC YIQ and PAL/SECAM YUV. YIQ color space represents the luminance, in-phase chrominance, and quadrature chrominance coordinates respectively. The only change between the PAL/SECAM YUV color space and the NTSC YIQ color space is a 33 degree rotation in UV plan. The digital equivalent of YUV is YCbCr, where the Cr chrominance component corresponds to the analog V component, and the Cb chrominance component corresponds to the analog U component, though with different scaling factors. The codec will use the terms Y, U, and V for Y, Cb, and Cr for a shorthand description of the digital YCbCr color space. The result is that the YCbCr elements are less correlated compared to RGB format and, therefore, can be coded separately without much loss in quality. The gain of data volume by converting from RGB to YCbCr is 2 to 1 (denoted 2:1). For example, if the RGB format is specified by eight bits for each color, then each RGB picture element is described by 24 bits; and after conversion and decimation, each YCbCr pixel is described by an average of 12 bits: the luminance at eight bits, and both the chrominances for every other pixel (horizontally and vertically) at eight bits. This technique was the first step toward video compression. Furthermore, video compression is achieved by exploiting similarities or redundancies that exists in typical video signal. A video sequence consists of a sequence of video frames or images. Each frame may be coded as a separate image. A frame to be coded is divided into a set of blocks, which can be compressed using two mains techniques. Block Discrete Cosing Transform (DCT) and Discrete Wavelet Transform (DWT). Coding each frame separately is not efficient since neighboring video frames are typically very similar. Much higher compression can be achieved by exploiting similarity between frames. A given frame can be predicted from a previous frame. The difference between the two frames is considered rather than the complete frame. Consecutive video frames typically contain the same imagery with possible different special locations because of motion. To improve the prediction, it is important to estimate the motion between the frames and to form an appropriate prediction that compensates this motion. This process is known as Motion Estimation. The process of forming a prediction in motion is called Motion Compensation. It 38
epresents the difference or error between the best-match frame block and the current to-be-coded frame block. In term of temporal location in video frames, three types of coded frames are generally generated by the codec. (1) Intra-coded frame (I-Frame) where the frame is coded independently of all the frames. (2) Predicatively coded frame or (P-Frame) where the frame is coded based on a previously coded frame. (3) Bi-directionally predicted frame (B-Frame) where the frame is coded using both previous and future coded frames. Figure 3-5 illustrates an MPEG video Group of Picture (GOP) coded using predictions dependencies between frames. I 1 B 2 B 3 P 4 B 5 B 6 P 7 Figure 3-5: Example of the prediction dependencies between frames Current video codecs achieve video compression by applying combination of the previously described techniques and which are: color space conversion, motion compensation, motion estimation, and signal transformation. Currently there are three families of video compression standards, performed under the auspices of ITU-T (International Telecommunication Union-Telecommunication), ISO (International Organization of Standardization) and IEC (International Electro-Technical Commission) as explained in Figure 3-6. A brief description of these standards is given in the next subsections. Audio-video compression standards ITU-T ITU-T and ISO ISO/IEC H.261 (1990) H.263 (1997) H.262 / MPEG-2 (1994) MPEG-1 (1991) MPEG-4 part 2 (1999) JVT: Joint Video Team H.264 / MPEG-4 Part 10 (2003) Figure 3-6: Current and emerging video compression standards 3.2.1.1.2 H.261 39
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UNIVERSITÉ DE VERSAILLES SAINT-QUE
Page 4 and 5: Résumé Nous constatons aujourd’
Page 6 and 7: 3 Related Work ....................
Page 8 and 9: 5.5.1.2 Simulation Results.........
Page 10 and 11: List of Figures Figure 1-1: Structu
Page 12 and 13: Figure 5-15: End-to-end packet tran
Page 14 and 15: Acknowledgments The first person I
Page 16 and 17: [11] Toufik Ahmed, Guillaume Burida
Page 18 and 19: d’accès. Les interactions de QoS
Page 20 and 21: Métrique MAX_DELAY PREF_MAX_DELAY
Page 22 and 23: 1.1.2 Proposition dun Protocole d'E
Page 24 and 25: des paquets RTP. Reste toujours le
Page 26 and 27: Nous pouvons distinguer trois possi
Page 28 and 29: 1.1.2.5.2 Multiplexage des Flux El
Page 30 and 31: l’horloge est par défaut égale
Page 32 and 33: La valeur R TCP représente le déb
Page 34 and 35: Pour ces raisons, nous nous intére
Page 36 and 37: Telles que illustrés par la Figure
Page 38 and 39: 3. DMIF2SIP vérifie si son propre
Page 40 and 41: utilisée optionnellement pour loca
Page 42 and 43: Chapter 2 2 Introduction 2.1 Motiva
Page 44 and 45: conditions. Based on end-to-end fee
Page 46 and 47: Chapter 3 3 Related Work Nowadays,
Page 48 and 49: • 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 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 and 100: Timestamp: Indicates the sampling i
Page 101 and 102: When G is used as generator matrix,
Page 103 and 104: 4.2.3 Performance Evaluation Intens
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0.3 0.25 our proposal classical app
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lost packet at the receiver. Conseq
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marking scheme. The server must be
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The video server adds audio-visual
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Marker (TR3CM) [131] to mark the ba
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VO1 VO2 AVO Scenario Audio BL EL1 E
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Throughput (Kbits) 3000 2500 2000 1
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Throughput (Kbits) 3000 2500 2000 1
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4000 3500 3000 2500 2000 1500 1000
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45 40 Original Quality Received Qua
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Chapter 5 5 A Dynamic Packet Video
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The TCM algorithm is based on a tok
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BEGIN Initialize the classification
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User Profile (Token Bucket) Traffic
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5.3.3 QoS Management Algorithm Spec
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Figure 5-7: Hierarchical aggregatio
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• Filters: to put packets into cl
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mechanism associated with the Drop
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Figure 5-16: Packets loss with IP D
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5.5.2.3 Experimental Results Figure
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1 MPEG-4 Based Layer Stream -AF11 M
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0.2 0.18 MPEG-4 Based Layer Stream
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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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