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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A.3.9 <strong>IP</strong>I_DescPointer<br />
<strong>IP</strong>I_DescPointer class contains a reference to the elementary stream that includes the<br />
<strong>IP</strong> Identification Data Set(s) that are valid for this stream. This indirect reference mechanism allows<br />
conveying <strong>IP</strong>_IdentificationDataSet elements only in one elementary stream while<br />
making references to it from any ES_Descriptor that shares the same <strong>IP</strong> Identification Data.<br />
A.3.10<br />
QoS Descriptor<br />
In our studies, QoS_descriptor is the important parameters of the classification.<br />
QoS_descriptor conveys the requirements that the ES has on the transport channel and a<br />
description of the traffic that this ES will generate. Table A-1 shows QoS parameters used in the<br />
OD of an ES. The unit of each metric is specified in Table A-2.<br />
QoS Metric<br />
Synthetic Description<br />
MAX_DELAY<br />
Absolute maximum end to end delay for the stream<br />
PREF_MAX_DELAY Preferred maximum end to end delay for the stream<br />
LOSS_PROB<br />
Allowable loss probability of any single AU.<br />
MAX_GAP_LOSS<br />
Maximum allowable number of consecutively lost Aus<br />
MAX_AU_SIZE<br />
Maximum size of an AU<br />
AVG_AU_SIZE<br />
Average size of an AU<br />
MAX_AU_RATE<br />
Maximum arrival rate of Aus<br />
PRIORITY<br />
Priority for the stream<br />
Table A-1: List of defined QoS metrics in MPEG-4 object descriptor<br />
QoS_QualifierTag Type Unit<br />
PRIORITY Byte Higher values mean higher priority<br />
MAX_DELAY Long Microseconds<br />
AVG_DELAY Long Microseconds<br />
LOSS_PROB Double Fraction (0.00 – 1.00)<br />
MAX_GAP_LOSS Long Integer number of Access Units (AU)<br />
MAX_AU_SIZE Long Bytes<br />
MAX_AU_RATE Long AUs/second<br />
AVG_AU_SIZE Double Bytes<br />
Table A-2: Metrics data syntax<br />
A.3.11<br />
ExtensionDescriptor<br />
Additional descriptors may be defined using the syntax in the class definitions above.<br />
Depending on the value of the class tag, the maximum length of the descriptor can be either 2 8 -1,<br />
2 16 -1 or 2 32 -1 byte.<br />
A terminal that conforms to this specification may ignore these descriptors. The available class<br />
tag values for extension descriptors allow ISO defined extensions as well as private extensions.<br />
A.3.12<br />
RegistrationDescriptor<br />
The registration descriptor provides a method to uniquely and unambiguously identify formats<br />
of private data streams.<br />
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