An XML Schema for the CLUE data model
draft-ietf-clue-data-model-schema-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8846.
|
|
|---|---|---|---|
| Authors | Roberta Presta , Simon Pietro Romano | ||
| Last updated | 2013-10-22 (Latest revision 2013-07-15) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
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| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 8846 (Proposed Standard) | |
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draft-ietf-clue-data-model-schema-00
CLUE Working Group R. Presta
Internet-Draft S P. Romano
Intended status: Informational University of Napoli
Expires: January 16, 2014 July 15, 2013
An XML Schema for the CLUE data model
draft-ietf-clue-data-model-schema-00
Abstract
This document provides an XML schema file for the definition of CLUE
data model types.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 16, 2014.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. <mediaCaptures> . . . . . . . . . . . . . . . . . . . . . . . 14
5. <encodings> . . . . . . . . . . . . . . . . . . . . . . . . . 14
6. <encodingGroups> . . . . . . . . . . . . . . . . . . . . . . . 14
7. <captureScenes> . . . . . . . . . . . . . . . . . . . . . . . 14
8. <simultaneousSets> . . . . . . . . . . . . . . . . . . . . . . 14
9. <captureEncodings> . . . . . . . . . . . . . . . . . . . . . . 14
10. <mediaCapture> . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. <capturedMedia> . . . . . . . . . . . . . . . . . . . . . 16
10.2. <captureSceneIDREF> . . . . . . . . . . . . . . . . . . . 16
10.3. <encGroupIDREF> . . . . . . . . . . . . . . . . . . . . . 16
10.4. <spatialInformation> . . . . . . . . . . . . . . . . . . 16
10.4.1. <capturePoint> . . . . . . . . . . . . . . . . . . . 17
10.4.2. <captureArea> . . . . . . . . . . . . . . . . . . . . 18
10.5. <nonSpatiallyDefinible> . . . . . . . . . . . . . . . . . 19
10.6. <description> . . . . . . . . . . . . . . . . . . . . . . 19
10.7. <priority> . . . . . . . . . . . . . . . . . . . . . . . 20
10.8. <lang> . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.9. <switched> . . . . . . . . . . . . . . . . . . . . . . . 20
10.10. <mobility> . . . . . . . . . . . . . . . . . . . . . . . 20
10.11. <composed> . . . . . . . . . . . . . . . . . . . . . . . 21
10.12. <maxCaptureEncodings> . . . . . . . . . . . . . . . . . . 21
10.13. <relatedTo> . . . . . . . . . . . . . . . . . . . . . . . 21
10.14. captureID attribute . . . . . . . . . . . . . . . . . . . 21
11. Audio captures . . . . . . . . . . . . . . . . . . . . . . . . 21
11.1. <audioChannelFormat> . . . . . . . . . . . . . . . . . . 22
12. Video captures . . . . . . . . . . . . . . . . . . . . . . . . 22
12.1. <embeddedText> . . . . . . . . . . . . . . . . . . . . . 23
13. Text captures . . . . . . . . . . . . . . . . . . . . . . . . 24
14. <captureScene> . . . . . . . . . . . . . . . . . . . . . . . . 24
14.1. <sceneEntries> . . . . . . . . . . . . . . . . . . . . . 25
14.2. sceneID attribute . . . . . . . . . . . . . . . . . . . . 25
14.3. scale attribute . . . . . . . . . . . . . . . . . . . . . 25
15. <sceneEntry> . . . . . . . . . . . . . . . . . . . . . . . . . 26
15.1. <switchingPolicies> . . . . . . . . . . . . . . . . . . . 26
15.2. <mediaCaptureIDs> . . . . . . . . . . . . . . . . . . . . 27
15.3. sceneEntryID attribute . . . . . . . . . . . . . . . . . 28
15.4. mediaType attribute . . . . . . . . . . . . . . . . . . . 28
16. <encoding> . . . . . . . . . . . . . . . . . . . . . . . . . . 28
16.1. <encodingName> . . . . . . . . . . . . . . . . . . . . . 28
16.2. <maxBandwidth> . . . . . . . . . . . . . . . . . . . . . 28
16.3. encodingID attribute . . . . . . . . . . . . . . . . . . 29
17. Audio encodings . . . . . . . . . . . . . . . . . . . . . . . 29
18. Video encodings . . . . . . . . . . . . . . . . . . . . . . . 29
18.1. <maxWidth> . . . . . . . . . . . . . . . . . . . . . . . 30
18.2. <maxHeight> . . . . . . . . . . . . . . . . . . . . . . . 30
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18.3. <maxFrameRate> . . . . . . . . . . . . . . . . . . . . . 30
19. H26X encodings . . . . . . . . . . . . . . . . . . . . . . . . 30
20. <encodingGroup> . . . . . . . . . . . . . . . . . . . . . . . 31
20.1. <maxGroupBandwidth> . . . . . . . . . . . . . . . . . . . 31
20.2. <maxGroupPps> . . . . . . . . . . . . . . . . . . . . . . 32
20.3. <encodingIDList> . . . . . . . . . . . . . . . . . . . . 32
20.4. encodingGroupID attribute . . . . . . . . . . . . . . . . 32
21. <simultaneousSet> . . . . . . . . . . . . . . . . . . . . . . 32
21.1. <captureIDREF> . . . . . . . . . . . . . . . . . . . . . 33
21.2. <sceneEntryIDREF> . . . . . . . . . . . . . . . . . . . . 33
22. <captureEncoding> . . . . . . . . . . . . . . . . . . . . . . 33
22.1. <mediaCaptureID> . . . . . . . . . . . . . . . . . . . . 34
22.2. <encodingID> . . . . . . . . . . . . . . . . . . . . . . 34
23. <clueInfo> . . . . . . . . . . . . . . . . . . . . . . . . . . 34
24. Sample XML file . . . . . . . . . . . . . . . . . . . . . . . 35
25. Diff with draft-presta-clue-data-model-schema-03 version . . 44
26. Informative References . . . . . . . . . . . . . . . . . . . . 44
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1. Introduction
This document provides an XML schema file for the definition of CLUE
data model types.
The schema is based on information contained in
[I-D.ietf-clue-framework] and also relates to the data model sketched
in [I-D.romanow-clue-data-model]. It encodes information and
constraints defined in the aforementioned documents in order to
provide a formal representation of the concepts therein presented.
The schema definition is intended to be modified according to changes
applied to the above mentioned CLUE documents.
The document actually represents a strawman proposal aiming at the
definition of a coherent structure for all the information associated
with the description of a telepresence scenario.
2. Terminology
[TBD] Copy text from the framework document.
3. XML Schema
This section contains the proposed CLUE data model schema definition.
The element and attribute definitions are formal representation of
the concepts needed to describe the capabilities of a media provider
and the current streams it is transmitting within a telepresence
session.
The main groups of information are:
<mediaCaptures>: the list of media captures available (Section 4)
<encodings>: the list of individual encodings (Section 5)
<encodingGroups>: the list of encodings groups (Section 6)
<captureScenes>: the list of capture scenes (Section 7)
<simultaneousSets>: the list of simultaneous transmission
sets(Section 8)
<captureEncodings>: the list of instantiated capture encodings
(Section 9)
All of the above refers to concepts that have been introduced in
[I-D.ietf-clue-framework] and [I-D.romanow-clue-data-model] and
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further detailed in threads on the mailing list as well as in the
following of this document.
<?xml version="1.0" encoding="UTF-8" ?>
<xs:schema
targetNamespace="urn:ietf:params:xml:ns:clue-info"
xmlns:tns="urn:ietf:params:xml:ns:clue-info"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns="urn:ietf:params:xml:ns:clue-info"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<!-- ELEMENT DEFINITIONS -->
<xs:element name="mediaCaptures" type="mediaCapturesType"/>
<xs:element name="encodings" type="encodingsType"/>
<xs:element name="encodingGroups" type="encodingGroupsType"/>
<xs:element name="captureScenes" type="captureScenesType"/>
<xs:element name="simultaneousSets" type="simultaneousSetsType"/>
<xs:element name="captureEncodings" type="captureEncodingsType"/>
<!-- MEDIA CAPTURES TYPE -->
<!-- envelope of media captures -->
<xs:complexType name="mediaCapturesType">
<xs:sequence>
<xs:element name="mediaCapture" type="mediaCaptureType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- DESCRIPTION element -->
<xs:element name="description">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
<!-- MEDIA CAPTURE TYPE -->
<xs:complexType name="mediaCaptureType" abstract="true">
<xs:sequence>
<!-- mandatory fields -->
<xs:element name="capturedMedia" type="xs:string"/>
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<xs:element name="captureSceneIDREF" type="xs:IDREF"/>
<xs:element name="encGroupIDREF" type="xs:IDREF"/>
<xs:choice>
<xs:sequence>
<xs:element name="spatialInformation"
type="tns:spatialInformationType"/>
</xs:sequence>
<xs:element name="nonSpatiallyDefinible" type="xs:boolean" fixed="true"/>
</xs:choice>
<!-- optional fields -->
<xs:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="priority" type="xs:unsignedInt" minOccurs="0"/>
<xs:element name="lang" type="xs:language" minOccurs="0"/>
<xs:element name="switched" type="xs:boolean" minOccurs="0"/>
<xs:element name="mobility" type="xs:mobilityType" minOccurs="0"/>
<xs:element name="composed" type="xs:boolean" minOccurs="0"/>
<xs:element name="maxCaptureEncodings" type="xs:unsignedInt"
minOccurs="0"/>
<!-- this is in place of "supplementary info": -->
<xs:element name="relatedTo" type="xs:IDREF" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="captureID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
<!-- SPATIAL INFORMATION TYPE -->
<xs:complexType name="spatialInformationType">
<xs:sequence>
<xs:element name="capturePoint" type="capturePointType"/>
<xs:element name="captureArea" type="captureAreaType"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
<!-- MOBILITY TYPE -->
<xs:simpleType name="mobilityType">
<xs:restriction base="xs:string">
<xs:enumeration value="static"/>
<xs:enumeration value="dynamic"/>
<xs:enumeration value="highly-dynamic"/>
</xs:restriction>
</xs:simpleType>
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<!-- TEXT CAPTURE TYPE -->
<xs:complexType name="textCaptureType">
<xs:complexContent>
<xs:extension base="tns:mediaCaptureType">
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- AUDIO CAPTURE TYPE -->
<xs:complexType name="audioCaptureType">
<xs:complexContent>
<xs:extension base="tns:mediaCaptureType">
<xs:sequence>
<xs:element name="audioChannelFormat" type="audioChannelFormatType"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- AUDIO CHANNEL FORMAT TYPE -->
<xs:simpleType name="audioChannelFormatType">
<xs:restriction base="xs:string">
<xs:enumeration value="mono"/>
<xs:enumeration value="stereo"/>
</xs:restriction>
</xs:simpleType>
<!-- VIDEO CAPTURE TYPE -->
<xs:complexType name="videoCaptureType">
<xs:complexContent>
<xs:extension base="tns:mediaCaptureType">
<xs:sequence>
<xs:element ref="embeddedText" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- EMBEDDED TEXT ELEMENT -->
<xs:element name="embeddedText">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:boolean">
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
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</xs:simpleContent>
</xs:complexType>
</xs:element>
<!-- CAPTURE SCENES TYPE -->
<!-- envelope of capture scenes -->
<xs:complexType name="captureScenesType">
<xs:sequence>
<xs:element name="captureScene" type="captureSceneType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- CAPTURE SCENE TYPE -->
<xs:complexType name="captureSceneType">
<xs:sequence>
<xs:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
<!-- <sceneSpace> has been removed from the XML Schema definition -->
<!--
<xs:element name="sceneSpace" type="captureSpaceType" minOccurs="0"/>
-->
<xs:element name="sceneEntries" type="sceneEntriesType"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="sceneID" type="xs:ID" use="required"/>
<xs:attribute name="scale" type="scaleType" use="required"/>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
<!-- SCALE TYPE -->
<xs:simpleType name="scaleType">
<xs:restriction base="xs:string">
<xs:enumeration value="millimeters"/>
<xs:enumeration value="unknown"/>
<xs:enumeration value="noscale"/>
</xs:restriction>
</xs:simpleType>
<!-- CAPTURE AREA TYPE -->
<xs:complexType name="captureAreaType">
<xs:sequence>
<xs:element name="bottomLeft" type="pointType"/>
<xs:element name="bottomRight" type="pointType"/>
<xs:element name="topLeft" type="pointType"/>
<xs:element name="topRight" type="pointType"/>
</xs:sequence>
</xs:complexType>
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<!-- CAPTURE SPACE TYPE -->
<xs:complexType name="captureSpaceType">
<xs:sequence>
<xs:element name="bottomLeftFront" type="pointType"/>
<xs:element name="bottomRightFront" type="pointType"/>
<xs:element name="topLeftFront" type="pointType"/>
<xs:element name="topRightFront" type="pointType"/>
<xs:element name="bottomLeftBack" type="pointType"/>
<xs:element name="bottomRightBack" type="pointType"/>
<xs:element name="topLeftBack" type="pointType"/>
<xs:element name="topRightBack" type="pointType"/>
</xs:sequence>
</xs:complexType>
<!-- POINT TYPE -->
<xs:complexType name="pointType">
<xs:sequence>
<xs:element name="x" type="xs:decimal"/>
<xs:element name="y" type="xs:decimal"/>
<xs:element name="z" type="xs:decimal"/>
</xs:sequence>
</xs:complexType>
<!-- CAPTURE POINT TYPE -->
<xs:complexType name="capturePointType">
<xs:complexContent>
<xs:extension base="pointType">
<xs:sequence>
<xs:element name="lineOfCapturePoint" type="tns:pointType"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="pointID" type="xs:ID"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- SCENE ENTRIES TYPE -->
<!-- envelope of scene entries of a capture scene -->
<xs:complexType name="sceneEntriesType">
<xs:sequence>
<xs:element name="sceneEntry" type="sceneEntryType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- SCENE ENTRY TYPE -->
<xs:complexType name="sceneEntryType">
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<xs:sequence>
<xs:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="switchingPolicies" type="switchingPoliciesType"
minOccurs="0"/>
<xs:element name="mediaCaptureIDs" type="captureIDListType"/>
</xs:sequence>
<xs:attribute name="sceneEntryID" type="xs:ID" use="required"/>
<xs:attribute name="mediaType" type="xs:string" use="required"/>
</xs:complexType>
<!-- SWITCHING POLICIES TYPE -->
<xs:complexType name="switchingPoliciesType">
<xs:sequence>
<xs:element name="siteSwitching" type="xs:boolean" minOccurs="0"/>
<xs:element name="segmentSwitching" type="xs:boolean"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<!-- CAPTURE ID LIST TYPE -->
<xs:complexType name="captureIDListType">
<xs:sequence>
<xs:element name="captureIDREF" type="xs:IDREF"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- ENCODINGS TYPE -->
<xs:complexType name="encodingsType">
<xs:sequence>
<xs:element name="encoding" type="encodingType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- ENCODING TYPE -->
<xs:complexType name="encodingType" abstract="true">
<xs:sequence>
<xs:element name="encodingName" type="xs:string"/>
<xs:element name="maxBandwidth" type="xs:unsignedInt"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="encodingID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<!-- AUDIO ENCODING TYPE -->
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<xs:complexType name="audioEncodingType">
<xs:complexContent>
<xs:extension base="tns:encodingType">
<xs:sequence>
<xs:element name="encodedMedia" type="xs:string" fixed="audio"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- VIDEO ENCODING TYPE -->
<xs:complexType name="videoEncodingType">
<xs:complexContent>
<xs:extension base="tns:encodingType">
<xs:sequence>
<xs:element name="encodedMedia" type="xs:string" fixed="video"
minOccurs="0"/>
<xs:element name="maxWidth" type="xs:unsignedInt" minOccurs="0"/>
<xs:element name="maxHeight" type="xs:unsignedInt" minOccurs="0"/>
<xs:element name="maxFrameRate" type="xs:unsignedInt" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- H26X ENCODING TYPE -->
<xs:complexType name="h26XEncodingType">
<xs:complexContent>
<xs:extension base="tns:videoEncodingType">
<xs:sequence>
<!-- max number of pixels to be processed per second -->
<xs:element name="maxH26Xpps" type="xs:unsignedInt"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- ENCODING GROUPS TYPE -->
<xs:complexType name="encodingGroupsType">
<xs:sequence>
<xs:element name="encodingGroup" type="tns:encodingGroupType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- ENCODING GROUP TYPE -->
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<xs:complexType name="encodingGroupType">
<xs:sequence>
<xs:element name="maxGroupBandwidth" type="xs:unsignedInt"/>
<xs:element name="maxGroupH264MacroBlockRate" type="xs:unsignedInt"
minOccurs="0"/>
<xs:element name="encodingIDList" type="encodingIDListType"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="encodingGroupID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<!-- ENCODING ID LIST TYPE -->
<xs:complexType name="encodingIDListType">
<xs:sequence>
<xs:element name="encIDREF" type="xs:IDREF" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- SIMULTANEOUS SETS TYPE -->
<xs:complexType name="simultaneousSetsType">
<xs:sequence>
<xs:element name="simultaneousSet" type="simultaneousSetType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- SIMULTANEOUS SET TYPE -->
<xs:complexType name="simultaneousSetType">
<xs:sequence>
<xs:element name="captureIDREF" type="xs:IDREF"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="sceneEntryIDREF" type="xs:IDREF"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="setID" type="xs:ID" use="required"/>
</xs:complexType>
<!-- CAPTURE ENCODINGS TYPE -->
<xs:complexType name="captureEncodingsType">
<xs:sequence>
<xs:element name="captureEncoding" type="captureEncodingType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
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<!-- CAPTURE ENCODING TYPE -->
<xs:complexType name="captureEncodingType">
<xs:sequence>
<xs:element name="mediaCaptureID" type="xs:string"/>
<xs:element name="encodingID" type="xs:string"/>
<xs:element name="captureParameters" type="captureParametersType"
minOccurs="0"/>
<xs:element name="encodingParameters" type="encodingParametersType"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="ID" type="xs:ID"/>
</xs:complexType>
<!-- CAPTURE PARAMETERS TYPE -->
<xs:complexType name="captureParametersType">
<xs:sequence>
<xs:element name="switchingOption" type="xs:string"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- ENCODING PARAMETERS TYPE -->
<xs:complexType name="captureParametersType">
<xs:sequence>
<xs:element name="bandwidth" type="xs:unsignedInt"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- CLUE INFO ELEMENT -->
<!-- the <clueInfo> envelope can be seen
as the ancestor of an <advertisement> envelope -->
<xs:element name="clueInfo" type="clueInfoType"/>
<!-- CLUE INFO TYPE -->
<xs:complexType name="clueInfoType">
<xs:sequence>
<xs:element ref="mediaCaptures"/>
<xs:element ref="encodings"/>
<xs:element ref="encodingGroups"/>
<xs:element ref="captureScenes"/>
<xs:element ref="simultaneousSets"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
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<xs:attribute name="clueInfoID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
</xs:schema>
Following sections describe the XML schema in more detail.
4. <mediaCaptures>
<mediaCaptures> represents the list of one ore more media captures
available on the media provider's side. Each media capture is
represented by a <mediaCapture> element (Section 10).
5. <encodings>
<encodings> represents the list of individual encodings available on
the media provider's side. Each individual encoding is represented
by an <encoding> element (Section 16).
6. <encodingGroups>
<encodingGroups> represents the list of the encoding groups organized
on the media provider's side. Each encoding group is represented by
a <encodingGroup> element (Section 20).
7. <captureScenes>
<captureScenes> represents the list of the capture scenes organized
on the media provider's side. Each capture scene is represented by a
<captureScene> element. (Section 14).
8. <simultaneousSets>
<simultaneousSets> contains the simultaneous sets indicated by the
media provider. Each simultaneous set is represented by a
<simultaneousSet> element. (Section 21).
9. <captureEncodings>
<captureEncodings> is a list of capture encodings. It can represents
the list of the desired capture encodings indicated by the media
consumer or the list of instantiated captures on the provider's side.
Each capture encoding is represented by a <captureEncoding> element.
(Section 22).
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10. <mediaCapture>
According to the CLUE framework, a media capture is the fundamental
representation of a media flow that is available on the provider's
side. Media captures are characterized with a set of features that
are independent from the specific type of medium, and with a set of
feature that are media-specific. We design the media capture type as
an abstract type, providing all the features that can be common to
all media types. Media-specific captures, such as video captures,
audio captures and others, are specialization of that media capture
type, as in a typical generalization-specialization hierarchy.
The following is the XML Schema definition of the media capture type:
<!-- MEDIA CAPTURE TYPE -->
<xs:complexType name="mediaCaptureType" abstract="true">
<xs:sequence>
<!-- mandatory fields -->
<xs:element name="capturedMedia" type="xs:string"/>
<xs:element name="captureSceneIDREF" type="xs:IDREF"/>
<xs:element name="encGroupIDREF" type="xs:IDREF"/>
<xs:choice>
<xs:sequence>
<xs:element name="spatialInformation"
type="tns:spatialInformationType"/>
</xs:sequence>
<xs:element name="nonSpatiallyDefinible" type="xs:boolean" fixed="true"/>
</xs:choice>
<!-- optional fields -->
<xs:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="priority" type="xs:unsignedInt" minOccurs="0"/>
<xs:element name="lang" type="xs:language" minOccurs="0"/>
<xs:element name="switched" type="xs:boolean" minOccurs="0"/>
<xs:element name="mobility" type="xs:mobilityType" minOccurs="0"/>
<xs:element name="composed" type="xs:boolean" minOccurs="0"/>
<xs:element name="maxCaptureEncodings" type="xs:unsignedInt"
minOccurs="0"/>
<!-- this is in place of "supplementary info": -->
<xs:element name="relatedTo" type="xs:IDREF" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="captureID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
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10.1. <capturedMedia>
<capturedMedia> is a mandatory field specifying the media type of the
capture ("audio", "video", "text",...).
10.2. <captureSceneIDREF>
<captureSceneIDREF> is a mandatory field containing the identifier of
the capture scene the media capture belongs to. Indeed, each media
capture must be associated with one and only capture scene. When a
media capture is spatially definible, some spatial information is
provided along with it in the form of point coordinates (see
Section 10.4). Such coordinates refers to the space of coordinates
defined for the capture scene containing the capture.
10.3. <encGroupIDREF>
<encGroupIDREF> is a mandatory field containing the identifier of the
encoding group the media capture is associated with.
10.4. <spatialInformation>
Media captures are divided into two categories: non spatially
definible captures and spatially definible captures.
Non spatially definible captures are those that do not capture parts
of the telepresence room. Capture of this case are for example those
related to registrations, text captures, DVDs, registered
presentation, or external streams, that are played in the
telepresence room and transmitted to remote sites.
Spatially definible captures are those that capture part of the
telepresence room. The captured part of the telepresence room is
described by means of the <spatialInformation> element.
This is the definition of the spatial information type:
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<!-- SPATIAL INFORMATION TYPE -->
<xs:complexType name="spatialInformationType">
<xs:sequence>
<xs:element name="capturePoint" type="capturePointType"/>
<xs:element name="captureArea" type="captureAreaType"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##other"
processContents="lax"/>
</xs:complexType>
The <capturePoint> contains the coordinates of the capture device
that is taking the capture, as well as, optionally, the pointing
direction (see Section 10.4.1). It is a mandatory field when the
media capture is spatially definible, independently from the media
type.
The <captureArea> is an optional field containing four points
defining the captured area represented by the capture (see
Section 10.4.2).
10.4.1. <capturePoint>
The <capturePoint> element is used to represent the position and the
line of capture of a capture device. The XML Schema definition of
the <capturePoint> element type is the following:
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<!-- CAPTURE POINT TYPE -->
<xs:complexType name="capturePointType">
<xs:complexContent>
<xs:extension base="pointType">
<xs:sequence>
<xs:element name="lineOfCapturePoint"
type="tns:pointType"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="pointID" type="xs:ID"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- POINT TYPE -->
<xs:complexType name="pointType">
<xs:sequence>
<xs:element name="x" type="xs:decimal"/>
<xs:element name="y" type="xs:decimal"/>
<xs:element name="z" type="xs:decimal"/>
</xs:sequence>
</xs:complexType>
The point type contains three spatial coordinates ("x","y","z")
representing a point in the space associated with a certain capture
scene.
The capture point type extends the point type, i.e., it is
represented by three coordinates identifying the position of the
capture device, but can add further information. Such further
information is conveyed by the <lineOfCapturePoint>, which is another
point-type element representing the "point on line of capture", that
gives the pointing direction of the capture device.
If the point of capture is not specified, it means the consumer
should not assume anything about the spatial location of the
capturing device.
The coordinates of the point on line of capture MUST NOT be identical
to the capture point coordinates. If the point on line of capture is
not specified, no assumptions are made about the axis of the
capturing device.
10.4.2. <captureArea>
<captureArea> is an optional element that can be contained within the
spatial information associated with a media capture. It represents
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the spatial area captured by the media capture.
The XML representation of that area is provided through a set of four
point-type element, <bottomLeft>, <bottomRight>, <topLeft>, and
<topRight>, as it can be seen from the following definition:
<!-- CAPTURE AREA TYPE -->
<xs:complexType name="captureAreaType">
<xs:sequence>
<xs:element name="bottomLeft" type="pointType"/>
<xs:element name="bottomRight" type="pointType"/>
<xs:element name="topLeft" type="pointType"/>
<xs:element name="topRight" type="pointType"/>
</xs:sequence>
</xs:complexType>
<bottomLeft>, <bottomRight>, <topLeft>, and <topRight> should be co-
planar.
For a switched capture that switches between different sections
within a larger area, the area of capture should use coordinates for
the larger potential area.
By comparing the capture area of different media captures within the
same capture scene, a consumer can determine the spatial
relationships between them and render them correctly. If the area of
capture is not specified, it means the Media Capture is not spatially
related to any other media capture.
10.5. <nonSpatiallyDefinible>
When media captures are non spatially definible, they are marked with
the boolean <nonSpatiallyDefinible> element set to "true".
10.6. <description>
<description> is used to provide optionally human-readable textual
information. It is used to describe media captures, capture scenes
and capture scene entries. A media capture can be described by using
multiple <description> elements, each one providing information in a
different language. Indeed, the <description> element definition is
the following:
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<!-- DESCRIPTION element -->
<xs:element name="description">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
As it can be seen, <description> is a string element with an
attribute ("lang") indicating the language used in the textual
description.
10.7. <priority>
<priority> ([I-D.groves-clue-capture-attr]) is an optional unsigned
integer field indicating the importance of a media capture according
to the media provider's perspective. It can be used on the
receiver's side to automatically identify the most "important"
contribution available from the media provider. The higher the
importance, the lower the contained value. When media captures are
marked with a "0" priority value, it means that they are "not subject
to priority".
[edt's note: discussion needed]
10.8. <lang>
<lang> is an optional element containing the language used in the
capture, if any. The purpose of the element could match the one of
the "language" attribute proposed in [I-D.groves-clue-capture-attr].
10.9. <switched>
<switched> is a boolean element which indicates whether or not the
media capture represents the most appropriate subset of a "whole".
What is "most appropriate" is up to the provider and could be the
active speaker, a lecturer or a VIP.
[edt note: :(]
10.10. <mobility>
<mobility> is an optional element indicating wheter or not the
capture device originating the capture moves during the telepresence
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session. That optional element can assume one of the three following
values: static, dynamic or highly dynamic, defined as in
[I-D.ietf-clue-framework].
10.11. <composed>
<composed> is an optional boolean element indicating wheter or not
the media capture is a mix (audio) or composition (video) of streams.
This attribute is useful for a media consumer for example to avoid
nesting a composed video capture into another composed capture or
rendering.
10.12. <maxCaptureEncodings>
The optional <maxCaptureEncodings> contains an unsigned integer
indicating the maximum number of capture encodings that can be
simultaneously active for the media capture. If absent, this
parameter defaults to 1. The minimum value for this attribute is 1.
The number of simultaneous capture encodings is also limited by the
restrictions of the encoding group the media capture refers to my
means of the <encGroupIDREF> element.
10.13. <relatedTo>
The optional <relatedTo> element contains the value of the ID
attribute of the media capture it refers to. The media capture
marked with a <relatedTo> element can be for example the translation
of a main media capture in a different language. The <relatedTo>
element could be interpreted the same manner of the supplementary
information attribute proposed in [I-D.groves-clue-capture-attr] and
further discussed in
http://www.ietf.org/mail-archive/web/clue/current/msg02238.html.
[edt note: There isn't yet final consensus about that element.]
10.14. captureID attribute
The "captureID" attribute is a mandatory field containing the
identifier of the media capture.
11. Audio captures
Audio captures inherit all the features of a generic media capture
and present further audio-specific characteristics. The XML Schema
definition of the audio capture type is reported below:
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<!-- AUDIO CAPTURE TYPE -->
<xs:complexType name="audioCaptureType">
<xs:complexContent>
<xs:extension base="tns:mediaCaptureType">
<xs:sequence>
<xs:element name="audioChannelFormat" type="audioChannelFormatType"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Audio-specific information about the audio capture is contained in
<audioChannelFormat> (Section 11.1).
11.1. <audioChannelFormat>
The optional <audioChannelFormat> element is a field with enumerated
values ("mono" and "stereo") which describes the method of encoding
used for audio. A value of "mono" means the audio capture has one
channel. A value of "stereo" means the audio capture has two audio
channels, left and right. A single stereo capture is different from
two mono captures that have a left-right spatial relationship. A
stereo capture maps to a single RTP stream, while each mono audio
capture maps to a separate RTP stream.
The XML Schema definition of the <audioChannelFormat> element type is
provided below:
<!-- AUDIO CHANNEL FORMAT TYPE -->
<xs:simpleType name="audioChannelFormatType">
<xs:restriction base="xs:string">
<xs:enumeration value="mono"/>
<xs:enumeration value="stereo"/>
</xs:restriction>
</xs:simpleType>
12. Video captures
Video captures, similarly to audio captures, extend the information
of a generic media capture with video-specific features, such as
<embeddedText> (Section 12.1).
The XML Schema representation of the video capture type is provided
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in the following:
<!-- VIDEO CAPTURE TYPE -->
<xs:complexType name="videoCaptureType">
<xs:complexContent>
<xs:extension base="tns:mediaCaptureType">
<xs:sequence>
<xs:element ref="embeddedText" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
12.1. <embeddedText>
The <embeddedText> element is a boolean element indicating that there
is text embedded in the video capture. The language used in such
embedded textual description is reported in <embeddedText> "lang"
attribute.
The XML Schema definition of the <embeddedText> element is:
<!-- EMBEDDED TEXT ELEMENT -->
<xs:element name="embeddedText">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:boolean">
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
The <embeddedText> element could correspond to the embedded-text
attribute introduced in [I-D.groves-clue-capture-attr]
[edt note: no final consensus has been reached yet about the adoption
of such element]
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13. Text captures
Also text captures can be described by extending the generic media
capture information, similarly to audio captures and video captures.
The XML Schema representation of the text capture type is currently
lacking text-specific information, as it can be seen by looking at
the definition below:
<!-- TEXT CAPTURE TYPE -->
<xs:complexType name="textCaptureType">
<xs:complexContent>
<xs:extension base="tns:mediaCaptureType">
</xs:extension>
</xs:complexContent>
</xs:complexType>
14. <captureScene>
A media provider organizes the available capture in capture scenes in
order to help the receiver both in the rendering and in the selection
of the group of captures. Capture scenes are made of capture scene
entries, that are set of media captures of the same media type. Each
capture scene entry represents an alternative to represent completely
a capture scene for a fixed media type.
The XML Schema representation of a <captureScene> element is the
following:
<!-- CAPTURE SCENE TYPE -->
<xs:complexType name="captureSceneType">
<xs:sequence>
<xs:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="sceneEntries" type="sceneEntriesType"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="sceneID" type="xs:ID" use="required"/>
<xs:attribute name="scale" type="scaleType" use="required"/>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
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The <captureScene> element can contain zero or more textual
<description> elements, defined as in Section 10.6. Besides
<description>, there the <sceneEntries> element (Section 14.1), which
is the list of the capture scene entries.
14.1. <sceneEntries>
The <sceneEntries> element is a mandatory field of a capture scene
containing the list of scene entries. Each scene entry is
represented by a <sceneEntry> element (Section 15).
<!-- SCENE ENTRIES TYPE -->
<!-- envelope of scene entries of a capture scene -->
<xs:complexType name="sceneEntriesType">
<xs:sequence>
<xs:element name="sceneEntry" type="sceneEntryType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
14.2. sceneID attribute
The sceneID attribute is a mandatory attribute containing the
identifier of the capture scene.
14.3. scale attribute
The scale attribute is a mandatory attribute that specifies the scale
of the coordinates provided in the spatial information of the media
capture belonging to the considered capture scene. The scale
attribute can assume three different values:
"millimeters" - the scale is in millimeters. Systems which know
their physical dimensions (for example professionally installed
telepresence room systems) should always provide those real-world
measurements.
"unknown" - the scale is not necessarily millimeters, but the
scale is the same for every media capture in the capture scene.
Systems which don't know specific physical dimensions but still
know relative distances should select "unknown" in the scale
attribute of the capture scene to be described.
"noscale" - there is no a common physical scale among the media
captures of the capture scene. That means the scale could be
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different for each media capture.
<!-- SCALE TYPE -->
<xs:simpleType name="scaleType">
<xs:restriction base="xs:string">
<xs:enumeration value="millimeters"/>
<xs:enumeration value="unknown"/>
<xs:enumeration value="noscale"/>
</xs:restriction>
</xs:simpleType>
15. <sceneEntry>
A <sceneEntry> element represents a capture scene entry, which
contains a set of media capture of the same media type describing a
capture scene.
A <sceneEntry> element is characterized as follows.
<!-- SCENE ENTRY TYPE -->
<xs:complexType name="sceneEntryType">
<xs:sequence>
<xs:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="switchingPolicies" type="switchingPoliciesType"
minOccurs="0"/>
<xs:element name="mediaCaptureIDs" type="captureIDListType"/>
</xs:sequence>
<xs:attribute name="sceneEntryID" type="xs:ID" use="required"/>
<xs:attribute name="mediaType" type="xs:string" use="required"/>
</xs:complexType>
One or more optional <description> elements provide human-readable
information about what the scene entry contains. <description> is
defined as already seen in Section 10.6.
The remaining child elements are described in the following
subsections.
15.1. <switchingPolicies>
<switchingPolicies> represents the switching policies the media
provider support for the media captures contained inside a scene
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entry. The <switchingPolicies> element contains two boolean
elements:
<siteSwitching>: if set to "true", it means that the media
provider supports the site switching policy for the included media
captures;
<segmentSwitching>: if set to "true", it means that the media
provider supports the segment switching policy for the included
media captures.
The "site-switch" policy means all captures are switched at the same
time to keep captures from the same endpoint site together.
The "segment-switch" policy means different captures can switch at
different times, and can be coming from different endpoints.
<!-- SWITCHING POLICIES TYPE -->
<xs:complexType name="switchingPoliciesType">
<xs:sequence>
<xs:element name="siteSwitching" type="xs:boolean" minOccurs="0"/>
<xs:element name="segmentSwitching" type="xs:boolean"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
15.2. <mediaCaptureIDs>
The <mediaCaptureIDs> is the list of the identifiers of the media
captures included in the scene entry. It is an element of the
captureIDListType type, which is defined as a sequence of
<captureIDREF> each one containing the identifier of a media capture
listed within the <mediaCaptures> element:
<!-- CAPTURE ID LIST TYPE -->
<xs:complexType name="captureIDListType">
<xs:sequence>
<xs:element name="captureIDREF" type="xs:IDREF"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
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15.3. sceneEntryID attribute
The sceneEntryID attribute is a mandatory attribute containing the
identifier of the capture scene entry represented by the <sceneEntry>
element.
15.4. mediaType attribute
The mediaType attribute contains the media type of the media captures
included in the scene entry.
16. <encoding>
The <encoding> element represents an individual encoding, i.e., a way
to encode a media capture. Individual encodings can be characterized
with features that are independent from the specific type of medium,
and with features that are media-specific. We design the individual
encoding type as an abstract type, providing all the features that
can be common to all media types. Media-specific individual
encodings, such as video encodings, audio encodings and others, are
specialization of that type, as in a typical generalization-
specialization hierarchy.
<!-- ENCODING TYPE -->
<xs:complexType name="encodingType" abstract="true">
<xs:sequence>
<xs:element name="encodingName" type="xs:string"/>
<xs:element name="maxBandwidth" type="xs:integer"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="encodingID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
16.1. <encodingName>
<encodingName> is a mandatory field containing the name of the
encoding (e.g., G711, H264, ...).
16.2. <maxBandwidth>
<maxBandwidth> represent the maximum bitrate the media provider can
instantiate for that encoding.
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16.3. encodingID attribute
The encodingID attribute is a mandatory attribute containing the
identifier of the individual encoding.
17. Audio encodings
Audio encodings inherit all the features of a generic individual
encoding and can present further audio-specific encoding
characteristics. The XML Schema definition of the audio encoding
type is reported below:
<!-- AUDIO ENCODING TYPE -->
<xs:complexType name="audioEncodingType">
<xs:complexContent>
<xs:extension base="tns:encodingType">
<xs:sequence>
<xs:element name="encodedMedia" type="xs:string" fixed="audio"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Up to now the only audio-specific information is the <encodedMedia>
element containing the media type of the media captures that can be
encoded with the considered individual encoding. In the case of
audio encoding, that element is forced to "audio".
18. Video encodings
Similarly to audio encodings, video encodings can extend the
information of a generic individual encoding with video-specific
encoding features, such as <maxWidth>, <maxHeight> and
<maxFrameRate>.
The <encodedMedia> element contains the media type of the media
captures that can be encoded with the considered individual encoding.
In the case of video encoding, that element is forced to "video".
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<!-- VIDEO ENCODING TYPE -->
<xs:complexType name="videoEncodingType">
<xs:complexContent>
<xs:extension base="tns:encodingType">
<xs:sequence>
<xs:element name="encodedMedia" type="xs:string" fixed="video"
minOccurs="0"/>
<xs:element name="maxWidth" type="xs:integer" minOccurs="0"/>
<xs:element name="maxHeight" type="xs:integer" minOccurs="0"/>
<xs:element name="maxFrameRate" type="xs:integer" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
18.1. <maxWidth>
<maxWidth> represents the video resolution's maximum width supported
by the video encoding, expressed in pixels.
[edt note: not present in -09 version of the framework doc]
18.2. <maxHeight>
<maxHeight> representd the video resolution's maximum heith supported
by the video encoding, expressed in pixels.
[edt note: not present in -09 version of the framework doc]
18.3. <maxFrameRate>
<maxFrameRate> provides the maximum frame rate supported by the video
encoding for the video capture to be encoded.
[edt note: not present in -09 version of the framework doc]
19. H26X encodings
This is an example of how it is possible to further specialize the
definition of a video individual encoding in order to cover encoding
specific information. A H26X video encoding can be represented
through an element inheriting the video encoding characteristics
described above (Section 18) and by adding other information such as
<maxH26Xpps>, which represent the maximum number of pixels to be
processed per second;.
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<!-- H26X ENCODING TYPE -->
<xs:complexType name="h26XEncodingType">
<xs:complexContent>
<xs:extension base="tns:videoEncodingType">
<xs:sequence>
<!-- max number of pixels to be processed per second -->
<xs:element name="maxH26Xpps" type="xs:integer"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
[edt note: Need to be checked]
20. <encodingGroup>
The <encodingGroup> element represents an encoding group, which is a
set of one or more individual encodings, and parameters that apply to
the group as a whole. The definition of the <encodingGroup> element
is the following:
<!-- ENCODING GROUP TYPE -->
<xs:complexType name="encodingGroupType">
<xs:sequence>
<xs:element name="maxGroupBandwidth" type="xs:integer"/>
<xs:element name="maxGroupPps" type="xs:integer"
minOccurs="0"/>
<xs:element name="encodingIDList" type="encodingIDListType"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="encodingGroupID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
In the following, the contained elements are further described.
20.1. <maxGroupBandwidth>
<maxGroupBandwidth> is an optional field containing the maximum
bitrate supported for all the individual encodings included in the
encoding group.
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20.2. <maxGroupPps>
<maxGroupPps> is an optional field containing the maximum number of
pixel per second for all the individual encodings included in the
encoding group.
[edt note: Need to be checked]
20.3. <encodingIDList>
<maxGroupBandwidth> is the list of the individual encoding grouped
together. Each individual encoding is represented through its
identifier contained within an <encIDREF> element.
<!-- ENCODING ID LIST TYPE -->
<xs:complexType name="encodingIDListType">
<xs:sequence>
<xs:element name="encIDREF" type="xs:IDREF" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
20.4. encodingGroupID attribute
The encodingGroupID attribute contains the identifier of the encoding
group.
21. <simultaneousSet>
<simultaneousSet> represents a simultaneous set, i.e. a list of
capture of the same type that cab be transmitted at the same time by
a media provider. There are different simultaneous transmission sets
for each media type.
<!-- SIMULTANEOUS SET TYPE -->
<xs:complexType name="simultaneousSetType">
<xs:sequence>
<xs:element name="captureIDREF" type="xs:IDREF"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="sceneEntryIDREF" type="xs:IDREF"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
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[edt note: need to be checked]
21.1. <captureIDREF>
<captureIDREF> contains the identifier of the media capture that
belongs to the simultanous set.
21.2. <sceneEntryIDREF>
<captureIDREF> contains the identifier of the scene entry containing
a group of capture that are able to be sent simultaneously with the
other capture of the simultaneous set.
22. <captureEncoding>
A <captureEncoding> is given from the association of a media capture
and an individual encoding, to form a capture stream as defined in
[I-D.ietf-clue-framework]. A media consumer expresses for each
capture encoding its preferences about the capture parameters (such
as the desired switching policy) and the encoding parameters (such as
the bandwidth). A possible solution to model such entity is provided
in the following.
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<!-- CAPTURE ENCODING TYPE -->
<xs:complexType name="captureEncodingType">
<xs:sequence>
<xs:element name="mediaCaptureID" type="xs:string"/>
<xs:element name="encodingID" type="xs:string"/>
<xs:element name="captureParameters" type="captureParametersType"
minOccurs="0"/>
<xs:element name="encodingParameters" type="encodingParametersType"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="ID" type="xs:ID"/>
</xs:complexType>
<!-- CAPTURE PARAMETERS TYPE -->
<xs:complexType name="captureParametersType">
<xs:sequence>
<xs:element name="switchingOption" type="xs:string"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- ENCODING PARAMETERS TYPE -->
<xs:complexType name="captureParametersType">
<xs:sequence>
<xs:element name="bandwidth" type="xs:unsignedInt"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
22.1. <mediaCaptureID>
<mediaCaptureID> contains the identifier of the media capture that
has been encoded to form the capture encoding.
22.2. <encodingID>
<encodingID> contains the identifier of the applied individual
encoding.
23. <clueInfo>
The <clueInfo> element has been left within the XML Schema for the
sake of convenience when representing a prototype of ADVERTISEMENT
message (see the example section).
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<!-- CLUE INFO ELEMENT -->
<!-- the <clueInfo> envelope can be seen
as the ancestor of an <advertisement> envelope -->
<xs:element name="clueInfo" type="clueInfoType"/>
<!-- CLUE INFO TYPE -->
<xs:complexType name="clueInfoType">
<xs:sequence>
<xs:element ref="mediaCaptures"/>
<xs:element ref="encodings"/>
<xs:element ref="encodingGroups"/>
<xs:element ref="captureScenes"/>
<xs:element ref="simultaneousSets"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="clueInfoID" type="xs:ID" use="required"/>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
24. Sample XML file
The following XML document represents a schema compliant example of a
CLUE telepresence scenario.
There are 5 video captures:
VC0: the video from the left camera
VC1: the video from the central camera
VC2: the video from the right camera
VC3: the overall view of the telepresence room taken from the
central camera
VC4: the video associated with the slide stream
There are 2 audio captures:
AC0: the overall room audio taken from the central camera
AC1: the audio associated with the slide stream presentation
The captures are organized into two capture scenes:
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CS1: this scene contains captures associated with the participants
that are in the telepresence room.
CS2: this scene contains captures associated with the slide
presentation, which is a pre-registered presentation played within
the context of the telepresence session.
Within the capture scene CS1, there are three scene entries
available:
CS1_SE1: this entry contains the partipants' video captures taken
from the three cameras (VC0, VC1, VC2).
CS1_SE2: this entry contains the zoomed-out view of the overall
telepresence room (VC3)
CS1_SE3: this entry contains the overall telepresence room audio
(AC0)
On the other hand, capture scene CS2 presents two scene entries:
CS2_SE1: this entry contains the presentation audio stream (AC1)
CS2_SE2: this entry contains the presentation video stream (VC4)
There are two encoding groups:
EG0 This encoding groups involves video encodings ENC0, ENC1, ENC2
EG1 This encoding groups involves audio encodings ENC3, ENC4
As to the simultaneous sets, only VC1 and VC3 cannot be transmitted
simultaneously since they are captured by the same device. i.e. the
central camera (VC3 is a zoomed-out view while VC1 is a focused view
of the front participants). The simultaneous sets would then be the
following:
SS1 made by VC0, VC1, VC2, VC4
SS2 made by VC0, VC3, VC2, VC4
SS3 made by AC0 and AC1
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<clueInfo xmlns="urn:ietf:params:xml:ns:clue-info" clueInfoID="prova">
<mediaCaptures>
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<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="audioCaptureType" captureID="AC1">
<capturedMedia>audio</capturedMedia>
<captureSceneIDREF>CS2</captureSceneIDREF>
<encGroupIDREF>EG1</encGroupIDREF>
<nonSpatiallyDefinible>true</nonSpatiallyDefinible>
<description lang="en">presentation audio</description>
<audioChannelFormat>mono</audioChannelFormat>
</mediaCapture>
<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoCaptureType" captureID="VC4">
<capturedMedia>video</capturedMedia>
<captureSceneIDREF>CS2</captureSceneIDREF>
<encGroupIDREF>EG0</encGroupIDREF>
<nonSpatiallyDefinible>true</nonSpatiallyDefinible>
<description lang="en">presentation video</description>
</mediaCapture>
<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="audioCaptureType" captureID="AC0">
<capturedMedia>audio</capturedMedia>
<captureSceneIDREF>CS1</captureSceneIDREF>
<encGroupIDREF>EG1</encGroupIDREF>
<spatialInformation>
<capturePoint>
<x>0.5</x>
<y>1.0</y>
<z>0.5</z>
<lineOfCapturePoint>
<x>0.5</x>
<y>0.0</y>
<z>0.5</z>
</lineOfCapturePoint>
</capturePoint>
</spatialInformation>
<description lang="en">
audio from the central camera mic</description>
<audioChannelFormat>mono</audioChannelFormat>
</mediaCapture>
<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoCaptureType" captureID="VC3">
<capturedMedia>video</capturedMedia>
<captureSceneIDREF>CS1</captureSceneIDREF>
<encGroupIDREF>EG0</encGroupIDREF>
<spatialInformation>
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<capturePoint>
<x>1.5</x>
<y>1.0</y>
<z>0.5</z>
<lineOfCapturePoint>
<x>1.5</x>
<y>0.0</y>
<z>0.5</z>
</lineOfCapturePoint>
</capturePoint>
<captureArea>
<bottomLeft>
<x>0.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomLeft>
<bottomRight>
<x>3.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomRight>
<topLeft>
<x>0.0</x>
<y>3.0</y>
<z>3.0</z>
</topLeft>
<topRight>
<x>3.0</x>
<y>3.0</y>
<z>3.0</z>
</topRight>
</captureArea>
</spatialInformation>
<description lang="en">
zoomed out view of the room</description>
</mediaCapture>
<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoCaptureType" captureID="VC2">
<capturedMedia>video</capturedMedia>
<captureSceneIDREF>CS1</captureSceneIDREF>
<encGroupIDREF>EG0</encGroupIDREF>
<spatialInformation>
<capturePoint>
<x>2.5</x>
<y>1.0</y>
<z>0.5</z>
<lineOfCapturePoint>
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<x>2.5</x>
<y>0.0</y>
<z>0.5</z>
</lineOfCapturePoint>
</capturePoint>
<captureArea>
<bottomLeft>
<x>2.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomLeft>
<bottomRight>
<x>3.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomRight>
<topLeft>
<x>2.0</x>
<y>3.0</y>
<z>3.0</z>
</topLeft>
<topRight>
<x>3.0</x>
<y>3.0</y>
<z>3.0</z>
</topRight>
</captureArea>
</spatialInformation>
<description lang="en">right camera video</description>
</mediaCapture>
<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoCaptureType" captureID="VC1">
<capturedMedia>video</capturedMedia>
<captureSceneIDREF>CS1</captureSceneIDREF>
<encGroupIDREF>EG0</encGroupIDREF>
<spatialInformation>
<capturePoint>
<x>1.5</x>
<y>1.0</y>
<z>0.5</z>
<lineOfCapturePoint>
<x>1.5</x>
<y>0.0</y>
<z>0.5</z>
</lineOfCapturePoint>
</capturePoint>
<captureArea>
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<bottomLeft>
<x>1.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomLeft>
<bottomRight>
<x>2.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomRight>
<topLeft>
<x>1.0</x>
<y>3.0</y>
<z>3.0</z>
</topLeft>
<topRight>
<x>2.0</x>
<y>3.0</y>
<z>3.0</z>
</topRight>
</captureArea>
</spatialInformation>
<description lang="en">central camera video</description>
</mediaCapture>
<mediaCapture
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoCaptureType" captureID="VC0">
<capturedMedia>video</capturedMedia>
<captureSceneIDREF>CS1</captureSceneIDREF>
<encGroupIDREF>EG0</encGroupIDREF>
<spatialInformation>
<capturePoint>
<x>0.5</x>
<y>1.0</y>
<z>0.5</z>
<lineOfCapturePoint>
<x>0.5</x>
<y>0.0</y>
<z>0.5</z>
</lineOfCapturePoint>
</capturePoint>
<captureArea>
<bottomLeft>
<x>0.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomLeft>
<bottomRight>
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<x>1.0</x>
<y>3.0</y>
<z>0.0</z>
</bottomRight>
<topLeft>
<x>0.0</x>
<y>3.0</y>
<z>3.0</z>
</topLeft>
<topRight>
<x>1.0</x>
<y>3.0</y>
<z>3.0</z>
</topRight>
</captureArea>
</spatialInformation>
<description lang="en">left camera video</description>
</mediaCapture>
</mediaCaptures>
<encodings>
<encoding xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoEncodingType" encodingID="ENC0">
<encodingName>h263</encodingName>
<maxBandwidth>4000000</maxBandwidth>
<encodedMedia>video</encodedMedia>
<maxWidth>1920</maxWidth>
<maxHeight>1088</maxHeight>
</encoding>
<encoding xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoEncodingType" encodingID="ENC1">
<encodingName>h263</encodingName>
<maxBandwidth>4000000</maxBandwidth>
<encodedMedia>video</encodedMedia>
<maxWidth>1920</maxWidth>
<maxHeight>1088</maxHeight>
</encoding>
<encoding xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="videoEncodingType" encodingID="ENC2">
<encodingName>h263</encodingName>
<maxBandwidth>4000000</maxBandwidth>
<encodedMedia>video</encodedMedia>
<maxWidth>1920</maxWidth>
<maxHeight>1088</maxHeight>
</encoding>
<encoding xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="audioEncodingType" encodingID="ENC3">
<encodingName>g711</encodingName>
<maxBandwidth>64000</maxBandwidth>
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<encodedMedia>audio</encodedMedia>
</encoding>
<encoding xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="audioEncodingType" encodingID="ENC4">
<encodingName>g711</encodingName>
<maxBandwidth>64000</maxBandwidth>
<encodedMedia>audio</encodedMedia>
</encoding>
</encodings>
<encodingGroups>
<encodingGroup encodingGroupID="EG0">
<maxGroupBandwidth>12000000</maxGroupBandwidth>
<encodingIDList>
<encIDREF>ENC0</encIDREF>
<encIDREF>ENC1</encIDREF>
<encIDREF>ENC2</encIDREF>
</encodingIDList>
</encodingGroup>
<encodingGroup encodingGroupID="EG1">
<maxGroupBandwidth>12000000</maxGroupBandwidth>
<encodingIDList>
<encIDREF>ENC3</encIDREF>
<encIDREF>ENC4</encIDREF>
</encodingIDList>
</encodingGroup>
</encodingGroups>
<captureScenes>
<captureScene scale="unknown" sceneID="CS1">
<description lang="en">main scene</description>
<sceneEntries>
<sceneEntry mediaType="video" sceneEntryID="SE1">
<description lang="en">
participants streams</description>
<mediaCaptureIDs>
<captureIDREF>VC0</captureIDREF>
<captureIDREF>VC1</captureIDREF>
<captureIDREF>VC2</captureIDREF>
</mediaCaptureIDs>
</sceneEntry>
<sceneEntry mediaType="video" sceneEntryID="SE2">
<description lang="en">room stream</description>
<mediaCaptureIDs>
<captureIDREF>VC3</captureIDREF>
</mediaCaptureIDs>
</sceneEntry>
<sceneEntry mediaType="audio" sceneEntryID="SE3">
<description lang="en">room audio</description>
<mediaCaptureIDs>
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<captureIDREF>AC0</captureIDREF>
</mediaCaptureIDs>
</sceneEntry>
</sceneEntries>
</captureScene>
<captureScene scale="noscale" sceneID="CS2">
<description lang="en">presentation</description>
<sceneEntries>
<sceneEntry mediaType="video" sceneEntryID="CS2_SE1">
<description lang="en">
presentation video</description>
<mediaCaptureIDs>
<captureIDREF>VC4</captureIDREF>
</mediaCaptureIDs>
</sceneEntry>
<sceneEntry mediaType="audio" sceneEntryID="CS2_SE2">
<description lang="en">
presentation audio</description>
<mediaCaptureIDs>
<captureIDREF>AC1</captureIDREF>
</mediaCaptureIDs>
</sceneEntry>
</sceneEntries>
</captureScene>
</captureScenes>
<simultaneousSets>
<simultaneousSet setID="SS1">
<captureIDREF>VC0</captureIDREF>
<captureIDREF>VC1</captureIDREF>
<captureIDREF>VC2</captureIDREF>
<captureIDREF>VC4</captureIDREF>
</simultaneousSet>
<simultaneousSet setID="SS2">
<captureIDREF>VC0</captureIDREF>
<captureIDREF>VC3</captureIDREF>
<captureIDREF>VC2</captureIDREF>
<captureIDREF>VC4</captureIDREF>
</simultaneousSet>
<simultaneousSet setID="SS3">
<captureIDREF>AC0</captureIDREF>
<captureIDREF>AC1</captureIDREF>
</simultaneousSet>
</simultaneousSets>
</clueInfo>
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25. Diff with draft-presta-clue-data-model-schema-03 version
sceneSpace element removed
content element removed
mobility element added in place of <dynamic>
xs:integer types changed into xs:unsignedInt types
micPattern element and type removed
nativeAspectRatio element removed
captureEncoding type definition updated - discussion needed
26. Informative References
[I-D.groves-clue-capture-attr] Groves, C., Yang, W., and R. Even,
"CLUE media capture description",
draft-groves-clue-capture-attr-01
(work in progress), February 2013.
[I-D.ietf-clue-framework] Duckworth, M., Pepperell, A., and S.
Wenger, "Framework for Telepresence
Multi-Streams",
draft-ietf-clue-framework-11 (work in
progress), July 2013.
[I-D.romanow-clue-data-model] Romanow, A. and A. Pepperell, "Data
model for the CLUE Framework",
draft-romanow-clue-data-model-01
(work in progress), June 2012.
[RFC4796] Hautakorpi, J. and G. Camarillo, "The
Session Description Protocol (SDP)
Content Attribute", RFC 4796,
February 2007.
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Authors' Addresses
Roberta Presta
University of Napoli
Via Claudio 21
Napoli 80125
Italy
EMail: roberta.presta@unina.it
Simon Pietro Romano
University of Napoli
Via Claudio 21
Napoli 80125
Italy
EMail: spromano@unina.it
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