Joint Source Network Coding for

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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.
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• 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.

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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)
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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.
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Scalable Overlay Video Streaming
Shivkumar Kalyanaraman, and
John W. Woods
Rensselaer Polytechnic Institute, USA
FGA-FEC Concept

• Bitstream is divided into small blocks
• FEC is added vertically across blocks

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• 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.

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Joint Design
The green bars are FEC data, others are original
video data.

• 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

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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.
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(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.

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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

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• 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