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30/C/1M. 30/C/1M. 30/C/2M. 30/C/3M. 15/Q/384k. DSN. 15/C/384k. 15/Q/1M. 30/C/3M. F. E. D. G. B. A. C. Server. DSN. DSN. Joint Source Network Coding for. Yufeng Shan, Ivan V. Bajic,
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30/C/1M 30/C/1M 30/C/2M 30/C/3M 15/Q/384k DSN 15/C/384k 15/Q/1M 30/C/3M F E D G B A C Server DSN DSN Joint Source Network Coding for Yufeng Shan, Ivan V. Bajic, Rensselaer Polytechnic Institute, USA Simon Fraser University, Canada JSNC uses overlay infrastructure to assist video streaming to heterogeneous users simultaneously by providing light weight support at intermediate overlay nodes. A-G : users and their requirements (frame rate/resolution/bit rate) DSN : Data service node, which performs data adaptation inside the network.
JSNC includes two basic concepts • Integrated Source-Network Video Coding (IVC) Video coding function is distributed both at source and inside the network to facilitate simple and precise adaptation of bitstream for heterogeneous users. • Fine Granular Adaptive FEC (FGA-FEC) Encoding once, the proposed FGA-FEC scheme can adapt the FEC coded bitstream to satisfy multiple heterogeneous users simultaneously without FEC decoding/re-encoding at intermediate overlay nodes.
Integrated Source Network Video Coding (IVC) • Server does video coding, DSNs adapt the bitstream based on network conditions and user requirements. • Each GOP coding unit consists of independent bitstreams {QMV, QYUV}. Motion vector bitstream (QMV) Lower resolution/quality /frame rate bitstreams are embedded in higher frame rate/resolution /quality bistreams and can be directly abstracted. Subband coefficient bitstream (QYUV)
Frame Rate Resolution Quality A(4,0,2) A(4,1,2) A(4,2,2) A(4,3,2) A(4,4,2) A(4,0.1) A(4,2,1) A(4,3,1) A(4,1,1) A(4,4,1) A(0,0,0) A(0,0,0) A(2,1,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(2,4,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(1,0,0) A(1,1,0) A(0,0,0) A(1,2,0) A(1,4,0) A(0,0,0) A(0,1,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(1,3,0) A(0,2,0) A(2,0,0) A(0,4,0) A(0,0,0) A(0,0,0) A(3,3,0) A(0,0,0) A(0,0,0) A(0,0,0) A(3,2,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(3,0,0) A(3,1,0) A(0,0,0) A(0,3,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(2,2,0) A(0,0,0) A(3,4,0) A(2,3,0) A(4,4,0) A(4,2,0) A(4,1,0) A(4,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(0,0,0) A(4,3,0) Encoded bitstream can be illustrated as Digital Items in view of three forms of scalability (frame rate /quality /resolution). A(F, Q, R) represents an atom of {frame rate, quality, resolution}. Intermediate DSNs adapt the digital items according to user preferences and network conditions, different subsets of atoms are chosen for different users.
A B C … X A1 B1 … … C1 … … … X1 Description 1 … … … B2 … … C2 … … Description 2 FEC B3 … Bi … … … C3 … … FEC FEC FEC FEC … … … C4 Cj FEC FEC FEC FEC … … FEC FEC FEC … … … … … … … … … Description n FEC FEC FEC FEC FEC Xn FEC FEC FEC Scalable Overlay Video Streaming Shivkumar Kalyanaraman, and John W. Woods Rensselaer Polytechnic Institute, USA • Bitstream is divided into small blocks; • FEC is added vertically across blocks; FGA-FEC Concept
Service Node • Each horizontal line is one description (packet). • When part of the video bitstream is actively dropped (adapted), FEC codes need to be updated accordingly by removing related block(s) from each description, no FEC transcoding is needed. • Green and blue blocks are removed from each description, including both original data and FEC blocks.
Joint Design • FGA-FEC encoded Scalable bitstream is reorganized for 3-D adaptatioin; • Adaptation of SNR can be easily achieved by removing related vertical blocks from each packets The green bars are FEC data, others are original video data.
Simulations Source Coding vs IVC Effect of block size on IVC Sequence: Foreman CIF; Encoder: MC-EZBC; IVC block size: 8 bytes; Available bandwidth 990 Kbps. JSNC is almost as precise as source coding, only 0.08 dB lower than source coding in this case.
(a) JSNC vs Random Drop (b) 3-D adaptation • 1500 Kbps bitstream to suit the 1455 Kbps channel; • 2 Mbps bistream is adapted to (1) SNR 512 Kbps; (2) Spatial to QCIF; and (3) Temporal to ¼ frame rate at intermediate overlay node.
Bit rate as layer adds up Number of bits in each layer • Compare the encoding efficiency with MD-FEC • JSNC is almost as good as MD-FEC
Bit allocation performance compare using JSNC and optimal solution; • The average JSNC is only 0.02 dB less than optimal solution • But with much faster speed, which can serve more users