TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI
TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI
TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI
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In RBF,<br />
2<br />
D = X − is the distance between X and U . ϕj(x) measures similarity, i.e. the<br />
k<br />
U k<br />
mapping function. λjk in the Figure is a set of scalar weights that connect each of the receptive<br />
fields to the class outputs of the network. The general equation of an output of the neuron j is<br />
given by:<br />
n<br />
∑<br />
F ( X ) = λ ϕ ( X )<br />
k<br />
j = 1<br />
jk<br />
j<br />
R<br />
j<br />
The classifier maps the vector X (an Audio Visual Object) to the class with the largest output:<br />
n<br />
{ x ∈ R / F ( x)<br />
≥ F ( x ∀k}<br />
≡ )<br />
j<br />
k<br />
{ (x)}<br />
F j<br />
A neural network takes in it input the feature vector X, produces computing class outputs<br />
, and then, classification decisions are made based on the largest output. The classification<br />
cannot be accomplished without knowing the characteristic of the underlying transport<br />
mechanisms.<br />
4.1.3 Performance Evaluation<br />
This section presents our experiment testbed, and some results got by using our MPEG-4<br />
platform. During experiments, two scenarios are investigated, the first on the standard MPEG-4<br />
framework (without any mechanism of QoS) and the second with the new MPEG-4 framework<br />
(with Classification Layer and prioritization mechanisms).<br />
We loaded the network by background traffic to generate congestion. Measurements are done<br />
to evaluate packet losses and end-to-end one-way delay from the server to the client.<br />
4.1.3.1 System and Network Models<br />
In our experiments, we have used an MPEG-4 video composed of three <strong>Video</strong> Objects. Each<br />
object is carried through an elementary stream. These objects are (see Figure 4-4 for more details):<br />
(1) Object 1: The logo at the top left of the MPEG-4 <strong>Video</strong>,<br />
(2) Object 2: The background of the MPEG-4 <strong>Video</strong>,<br />
(3) Object 3: The person.<br />
Scene<br />
logo<br />
Background<br />
Speaker<br />
MPEG-4 Scene<br />
Figure 4-4: MPEG-4 scene used for experiment<br />
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