Copyright © 2011 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This is the Candidate Recommendation of the API for Media Resources 1.0 specification.
It has been produced by the Media Annotations Working Group, which is part of the W3C Video on the Web Activity. The Working Group expects to advance this specification to Recommendation Status.
Please send review comments about this Candidate Recommendation to the public mailing list public-media-annotation@w3.org mailing list (public archive). Use "[CR Comment API]" in the subject line of your email. We expect that sufficient feedback to determine its future will have been received by 31 December 2011. This specification will remain a Candidate Recommendation until at least 31 December 2011.
The Media Annotation Working Group will advance this specification to Proposed Recommendation when the following exit criteria have been met:
1. Sufficient reports of implementation experience have been gathered to demonstrate that the API features are implementable and are interpreted in a consistent manner. To do so, the Working Group will insure that all features in the API for Media Resources 1.0 specification have been implemented at least twice in an interoperable way. The following elements are considered features of the API and must be tested by the test suite:
The API is designed for both client- and server side implementations. Depending on whether the API is implemented in a user agent or plugin, or as a web service, different communication patterns are more appropriate. In the client side case, asynchronous access is typically preferred, while synchronous access is more appropriate for a web service. Thus the two version of the interface are not considered distinct features but different modes of access for the different use cases.
2. The implementations have been developed independently.
3. The Working Group has adopted a public test suite and has produced an implementation report for this API for Media Resources 1.0.
The Implementation results are publicly released and are intended solely to be used as proof of Media API 1.0 implementability. It is only a snap shot of the actual implementation behaviors at one moment of time, as these implementations may not be immediately available to the public. The interoperability data is not intended to be used for assessing or grading the performance of any individual implementation. Any feedback on implementation and use of this specification would be very welcome. To the extent possible, please provide a separate email message for each distinct comment.
For convenience, the differences between this CR version and the Second Last Call Working Draft are highlighted in the CR Diff file and listed in the change log in Annexe B.
This W3C Working Draft version of the API for Media Resources 1.0 specification incorporates requests for changes from comments sent during the first and second Last Call Review, as agreed with the commenters (see Disposition of Last Call comments for Ontology for Media Resources 1.0) and changes following implementation experiences from the Working Group.
Publication as a Candidate Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
MediaResource
interface
AsyncMediaResource
interface
SyncMediaResource
interface
MediaAnnotation
interface
MetadataSource
interface
This specification defines an API to access metadata information related to media resources on the Web. The overall purpose is to provide developers with a convenient access to metadata information stored in different metadata formats. The core properties, defined in the Ontology for Media Resources 1.0 specification, will be used as a pivot vocabulary in this API. The description of relations between these core properties and the metadata formats in scope are documented in the Ontology for Media Resources 1.0 specification in order to provide cross-community data integration. This API is described using the interface definition language Web IDL [WEBIDL]. The decision to use Web IDL, which offers bindings for ECMAScript and Java, can be based on the Use Cases and Requirements for Ontology and API for Media Resources 1.0 [MEDIA-ANNOT-REQS].
This API defines/exposes interfaces that enables users/applications to consume metadata in an interoperable manner. Here, interoperability between metadata formats is ensured by the use of the Ontology for Media Resources 1.0 as pivot metadata format. This API offers operations to request particular metadata information represented in a certain metadata format related to media resources on the Web. Further it specifies the actual representation of the core properties and the behaviour of this API.
Refers to the formats in scope of Ontology for Media Resources 1.0.
Refers to the Formats out of scope of Ontology for Media Resources 1.0.
In this document the terms "Ontology", "Media Resource", "Property", "Mapping" and "Property value types" are to be interpreted as defined in Section 2 of Ontology for Media Resources 1.0.
As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.
The key words must, must not, required, should, should not, recommended, may, and optional in this specification are to be interpreted as described in [RFC2119].
Before introducing the two example usage scenarios of this API, two modes of operations must be defined: asynchronous and synchronous mode. For this API the asynchronous mode is considered to be used as default where calls return without waiting for the request to finish its execution: a call-back function is provided to be invoked when the request terminates. In contrast to that, the synchronous mode implicates an immediate answer to every request.
We consider two scenarios, where this API could be implemented:
User agent
Web Service
The two scenarios are shown in Figure 1.
Note: This specification only defines this API for Media Resources. Other components depicted in Figure 1 (e.g., access/extraction/storage of metadata) are not covered.
In both scenarios, this API serves as a mediator between a client application and the actual metadata sources. Interoperability is ensured by defining i) operations for accessing the metadata information, ii) common object structure and iii) API behaviour (e.g., status codes). Following this, an implementation has to implement this stack of components:
An implementation of the API for Media Resources (as defined in this document), which provides the actual GETTER methods for the properties.
An implementation of the mappings from a specific source format to the core properties. Here, the API for Media Resources 1.0 may use the Ontology for Media Resources 1.0 specification.
A format specific API to access the metadata. This can be an API for retrieving a metadata document describing a media resource (e.g. an XML parser and a set of XPath statements) or an extractor to read metadata embedded in the media resource (e.g. a library to read EXIF information from JPEG images). In order to define the context in which this API is applied, at least a unidirectional reference from the media resource to the metadata document or vice versa is needed. If this is not the case such a reference needs to be provided by the web application (scenario 1), web service (scenario 2) or media repository (scenario 2).
Note that, this API provides access to metadata information stored in different metadata formats. As such, different instances of the same property can exist.
This API defines a number of interfaces using [WEBIDL]. These can be grouped in the following categories:
Interfaces defining the actual retrieval operations for metadata,
called MediaResource
, and provided in both synchronous and
asynchronous versions (see Section 4.1, Section 4.2 and Section
4.3)
Interfaces defining the data structure of response objects/metadata
annotations, called MediaAnnotation
(see Section 4.4 and Section 4.5)
An interfaces defining a data structure for metadata sources, called
MetadataSource
(see Section
4.6)
Next, the different interfaces and exposed operations (in case of the
MediaResource
interfaces and its implementing interfaces) are
discussed. Implementations of this API must support at least one of the versions and must support the other interfaces defined in
this document. We have not specified exceptions on the operations or on
accessing the attributes. Instead, a status code is returned (in the
synchronous API) or can be accessed (in the asynchronous API) in case an error
occurs indicating the state of processing (see Section 4.7).
Then, the interfaces for the return types, i.e.,
MediaAnnotation
and its specializations, and
MetadataSource
are defined.
The IDL fragment in Appendix A of this specification must be interpreted as required for conforming IDL fragments, as described in the “Web IDL” specification. [WEBIDL]
MediaResource
interfaceThe MediaResource
interface is the core of this API and
provides operations to access the metadata properties of a specific media
resource. Here, a clear separation between asynchronous and synchronous mode of
operation has been achieved by defining two implementing interfaces, the
AsyncMediaResource
and the SyncMediaResource
interface. Objects of these interfaces will be created by calling
createMediaResource
of the MediaResource
interface.
The actual connection to a specified metadata source will be created with the
execution of the getMediaProperty
operation of
AsyncMediaResource
or SyncMediaResource
interface.
interface MediaResource {
short getSupportedModes ();
MediaResource
createMediaResource (DOMString mediaResource, optional MetadataSource
[] metadataSources, optional short mode);
};
createMediaResource
AsyncMediaResource
or SyncMediaResource
interface. Further, it allows to set the specific media resource and
metadata sources to which this API is applied.
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
mediaResource | DOMString |
✘ | ✘ | This attribute must set the specific media resource that should be processed by the API. |
metadataSources |
|
✘ | ✔ | This attribute should specify additional metadata sources. |
mode | short |
✘ | ✔ | This attribute should specify the desired mode
of operation. 1 for asynchronous and
2 for synchronous mode should be used. |
MediaResource
getSupportedModes
1
for asynchronous,
2
for synchronous and 3
for both
modes.
short
Example for getSupportedModes
:
ma = new MediaResource(); var mode = ma.getSupportedModes(); /** Resulting in: * { "supportedModes" : 3 } */
Example for createMediaResource
:
metadataSources = new MetadataSource[2]; metadataSources[0] = new MetadataSource( "http://www.w3.org/2008/WebVideo/Annotations/drafts/metadata_formats/DC_example1.xml","dc"); metadataSources[1] = new MetadataSource( "http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG","exif"); mediaResource = new MediaResource(); if (mediaResource.getSupportedModes() == 1 || mediaResource.getSupportedModes() == 3) { aSyncObject = mediaResource.createMediaResource( "http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG", metadataSources, 1); } else if (mediaResource.getSupportedModes() == 2 || mediaResource.getSupportedModes() == 3) { syncObject = mediaResource.createMediaResource( "http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG", metadataSources, 2); }
AsyncMediaResource
interfaceThe AsyncMediaResource
interface provides a number of
operations that allow accessing the metadata of a media resource. By calling
the getMediaProperty
operation with the argument "title" we can
retrieve the title of the corresponding media resource.
Next, we give the Web IDL description of the AsyncMediaResource
interface and describe the different operations that are part of it. The
mediaResource argument identifies the media resource, for which the
implementation of this API should try to find relevant metadata sources.
Optionally, references to metadata sources can be passed using an array of
objects, each implementing the MetadataSource
interface. This
interface holds an URI identifying the metadata source (metadataSource) and the
name of the actual metadata format (sourceFormat).
In this section the MediaAnnotations
interface is
used in the interface definitions. It serves as a container to hold general
values about properties enabling an iteration over a set of different
properties. Its explanation can be found in Section 4.4
interface AsyncMediaResource : MediaResource
{
void getMediaProperty (DOMString[] propertyNames, PropertyCallback
successCallback, ErrorCallback errorCallback, optional DOMString fragment, optional DOMString sourceFormat, optional DOMString language);
void getOriginalMetadata (DOMString sourceFormat, MetadataCallback
successCallback, ErrorCallback errorCallback);
};
getMediaProperty
MediaAnnotation
interface, described in Section 4.4. Depending on the requested
property, the returned objects implement a different subtypes (inheriting
from the MediaAnnotation
interface). Requesting "title"
gives back an array of objects implementing the Title
interface, requesting "creator" results in objects implementing the
Creator
interface and so on. These interfaces are described
in Section 4.5. An example can be found here.
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
propertyNames | DOMString[] |
✘ | ✘ | This argument identifies an array containing the properties for which the values need to be retrieved. For an empty array all properties carrying values will be retrieved. Optional arguments allow refining the request. |
successCallback |
|
✘ | ✘ | This argument holds a callback object for
asynchronous requests to the property. The
successCallback object implements the
PropertyCallback interface and holds a
handleEvent operation that needs to be called once
all data for the requested property is gathered. This
handleEvent operation needs to be called with a new
MediaAnnotation array. |
errorCallback | ErrorCallback |
✘ | ✘ | This argument holds a callback object for
failure of asynchronous requests to the property. The
errorCallback object implements the
ErrorCallback interface and holds a
handleEvent operation that needs to be called if an
attempt fails. This handleEvent operation needs to
be called with a new DOMString representing the status code of
the error (see Section 4.7 for
details). |
fragment | DOMString |
✘ | ✔ | This argument contains a URI identifying the specific media fragment for which the metadata is requested. The URI must conform to the URI for Media Fragment [MEDIA-FRAGMENTS] specification. This parameter is optional. |
sourceFormat | DOMString |
✘ | ✔ | This argument identifies a specific metadata format. It should use the metadata format identifiers defined in the Ontology for Media Resources 1.0 specification. If a metadata format is defined, only the metadata available in the corresponding metadata format are retrieved. This parameter is optional. |
language | DOMString |
✘ | ✔ | This argument allows to identify the language of the metadata. Values for the metadata will only be returned if it is available in the specified language. Recommended best practice is to use BCP 47 [BCP47]. This parameter is optional. |
void
getOriginalMetadata
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
sourceFormat | DOMString |
✘ | ✘ | This argument identifies a specific metadata format. It should use the metadata format identifiers defined in the Ontology for Media Resources 1.0 specification. If a metadata format is defined, only the metadata available in the corresponding metadata format are retrieved. |
successCallback |
|
✘ | ✘ | This argument holds a callback object for
asynchronous requests for the original metadata. The
successCallback object implements the
MetadataCallback interface and holds a
handleEvent operation that needs to be called once
all properties having values are listed. This
handleEvent operation needs to be called with a new
DOMString array holding the original metadata. |
errorCallback | ErrorCallback |
✘ | ✘ | This argument holds a callback object for
failure of asynchronous requests for the original metadata. The
errorCallback object implements the
ErrorCallback interface and holds a
handleEvent operation that needs to be called if an
attempt fails. This handleEvent operation needs to
be called with a new DOMString representing the status code of
the error (see Section 4.7 for
details). |
void
PropertyCallback
interfaceThe PropertyCallback
interface holds a
handleEvent
operation that needs to be called once all data for
the requested property has been gathered.
interface PropertyCallback {
void handleEvent (MediaAnnotation
[] mediaAnnotations);
};
handleEvent
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
mediaAnnotations |
|
✘ | ✘ | This argument holds a list of objects with
values according to the requested property. These objects
implement the MediaAnnotation interface, described
in Section 4.4. Depending on
the requested property, the returned objects implement a
different subtypes (inheriting from the
MediaAnnotation interface). |
void
MetadataCallback
interfaceThe MetadataCallback
interface holds a
handleEvent
operation that needs to be called once the requested
metadata has been gathered.
interface MetadataCallback {
void handleEvent (DOMString[] metadata);
};
handleEvent
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
metadata | DOMString[] |
✘ | ✘ | This argument holds a list of DOMStrings representing the original metadata. Note that, multiple metadata instances can exist (e.g., one Dublin core and one MPEG-7 document). |
void
Example for asynchronous
getMediaProperty
:
aSyncMediaResource = mediaResource.createMediaResource("http://www.imdb.com/title/tt0133152/", new Array(), 1); aSyncMediaResource.getMediaProperty(["title"], successCallback, errorCallback, "", "", ""); function successCallback(MediaAnnotation[] mediaAnnotations) { ... } /** Resulting in: * [ { "Title" : { * "propertyName" : "title", * "value" : "Planet of the apes", * "language" : en-us", * ... * "statusCode" : 200 * } * }, * { "Title" : { * "propertyName" : "title", * "value" : "Monkey Planet", * "language" : en-us", * ..., * "statusCode" : 200 * } * }, * { ... * } ] */ function errorCallback(DOMString error) { ... } /** Resulting in: * { error: { "statusCode" : 415 } } */
Example for asynchronous
getOriginalMetadata
:
aSyncMediaResource = mediaResource.createMediaResource( "http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG", new Array(), 1); aSyncMediaResource.getOriginalMetadata("dc", successCallback, errorCallback); function successCallback(DOMString[] metadata) { ... } /** Resulting in: * [ { "statusCode" : 200 * }, * {"originalMetadata" : "<metadata xmlns='http://example.org/myapp/' * xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' * xsi:schemaLocation='http://example.org/myapp/ http://example.org/myapp/schema.xsd' * xmlns:dc='http://purl.org/dc/elements/1.1/'> * <dc:title>DC title</dc:title> * </metadata>" * } ] */ function errorCallback(DOMString error) { ... } /** Resulting in: * { error: { "statusCode" : 415 } } */
SyncMediaResource
interfaceThe SyncMediaResource
interface provides a number of operations
to access the metadata of a media resource. Next, we give the Web IDL
description of the SyncMediaResource
interface for synchronous
requests and describe the different operations that are part of it. The
MediaResource
defines a constructor that can be called to
construct the object based on an identifier of the media resource and
optionally some metadata sources. The mediaResource argument identifies the
media resource, for which the implementation of this API should try to find
relevant metadata sources. Optionally, references to metadata sources can be
passed using an array of objects, each implementing the
MetadataSource
interface. This interface holds two attributes,
namely an URI identifying the metadata source (metadataSource
) and
the name of the actual metadata format (sourceFormat
). An example,
how to create this object can be found here.
interface SyncMediaResource : MediaResource
{
MediaAnnotation
[] getMediaProperty (DOMString[] propertyNames, optional DOMString fragment, optional DOMString sourceFormat, optional DOMString language);
DOMString[] getOriginalMetadata (DOMString sourceFormat);
};
getMediaProperty
MediaAnnotation
interface
(see Section 4.3). Depending on the
requested property, the returned objects implement a different subtypes
(inheriting from the MediaAnnotation
interface). Requesting
"title" gives back an array of objects implementing the
Title
interface, requesting "creator" results in objects
implementing the Creator
interface and so on. These subtypes
are described in Section 4.4. The operation
returns a MediaAnnotation
array holding the requested
properties. If an error occurs during retrieval, a
MediaAnnotation
object with the corresponding status code
(e.g., 400, 404 or 415) will be generated and inserted at the first
position of the array. An example can be found here.
In this section the MediaAnnotations
interface is used in the interface definitions. It serves as a container
to hold general values about properties enabling an iteration over a set
of different properties. Its explanation can be found in Section 4.4
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
propertyNames | DOMString[] |
✘ | ✘ | This argument holds the requested properties as an array. If the array is empty, each property holding values will be returned. |
fragment | DOMString |
✘ | ✔ | This argument contains a URI identifying the specific media fragment for which the metadata is requested. The URI must conform to the URI for Media Fragment[MEDIA-FRAGMENTS] specification. This parameter is optional. |
sourceFormat | DOMString |
✘ | ✔ | This argument identifies a specific metadata format. It should use the metadata format identifiers defined in the Ontology for Media Resources 1.0 specification. If a metadata format is defined, only the metadata available in the corresponding metadata format is retrieved. This parameter is optional. |
language | DOMString |
✘ | ✔ | This argument allows to identify the language of the metadata. Values for the metadata will only be returned if it is available in the specified language. Recommended best practice is to use BCP 47 [BCP47]. This parameter is optional. |
MediaAnnotation
[]
getOriginalMetadata
DOMString
array holding the status code of the
request at the first and the original metadata at the second position. An
example can be found here.
Parameter | Type | Nullable | Optional | Description |
---|---|---|---|---|
sourceFormat | DOMString |
✘ | ✘ | This argument identifies a specific metadata format. It should use the metadata format identifiers defined in the Ontology for Media Resources 1.0 specification. If a metadata format is defined, only the metadata available in the corresponding metadata format is retrieved. |
DOMString[]
The examples in this section use
getMediaProperty()
to get an object implementing the
MediaAnnotation
interface. The noErrorStatus
function
ensures that no error is present and the requested properties carry values.
We give some JavaScript examples on how to use the synchronous
MediaResource
interface and it's operations.
Example for synchronous
getMediaProperty
:
syncMediaResource = mediaResource.createMediaResource("http://www.imdb.com/title/tt0133152/", new Array(), 2); title = syncMediaResource.getMediaProperty(["title"], "", "", ""); if (noErrorStatus(title[0].statusCode) == true) { ... } /** Resulting in: * [ { "Title" : { * "propertyName" : "title", * "value" : "Planet of the apes", * "language" : en-us", * ..., * "statusCode" : 200 * } * }, * { "Title" : { * "propertyName" : "title", * "value" : "Planet der Affen", * "language" : "de-de", * ..., * "statusCode" : 200 * } * }, * { ... * } ] */
Example for synchronous
getOriginalMetadata
:
syncMediaResource = mediaResource.createMediaResource("http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG", new Array(), 2); dcMetadata = syncMediaResource.getOriginalMetadata("DC"); if (noErrorStatus(dcMetadata[0].statusCode) == true) { ... } /** Resulting in: * [ { "statusCode" : 200 * }, * {"originalMetadata" : "<metadata xmlns='http://example.org/myapp/' * xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' * xsi:schemaLocation='http://example.org/myapp/ http://example.org/myapp/schema.xsd' * xmlns:dc='http://purl.org/dc/elements/1.1/'> * <dc:title>DC title</dc:title> * </metadata>" * } ] */
MediaAnnotation
interfaceMediaAnnotation
interface is used as the return type of
MediaResource.getMediaProperty
operation. It is a container to
hold general values about properties enabling an iteration over a set of
different properties. Depending on the requested property, this interface will
be enlarged by more specific attributes.
As several properties are complex types, specific derived types of
MediaAnnotation
have been defined, added these properties with the
appropriate types. However, MediaAnnotation
can be used as a
generic return type to access a printable string representation of the property
(in the value
attribute). It also includes a status code. In case
of general errors, the first element of the returned
MediaAnnotation
array contains the global error code, otherwise
the status can be given for each of the returned properties.
The following design considerations have been used for specifying the derived types for each of the properties:
MediaAnnotation
, adding typed attributes according to the
specification in the ontology document.value
with a printable string representation, it is
recommended to follow these steps:
value
a string that is
found in another attribute. This is considered an acceptable amount of
redundancy for the benefit of having a generic value field for all
properties that can be used regardless of the specific property and data
type of the attributes.URI|string
, the interface shall
have two attributes, one with "Link" and one with "Label" appended to the
attribute name, representing the URI and string respectivelyMediaAnnotation
or one of the derived interfaces for one of
the properties.interface MediaAnnotation {
attribute DOMString propertyName;
attribute DOMString value;
attribute DOMString language;
attribute DOMString sourceFormat;
attribute DOMString fragmentIdentifier;
attribute DOMString mappingType;
attribute short statusCode;
};
fragmentIdentifier
of type DOMStringlanguage
of type DOMStringmappingType
of type
DOMStringpropertyName
of type
DOMStringsourceFormat
of type
DOMStringstatusCode
of type
shortvalue
of type DOMStringThe noErrorStatus
function ensures that no error
is present and the requested properties carry values. The
MediaAnnotation
interface will be never instantiated - only the
implementing subtypes will be created. These must be filled at least with the parameters specified in
the MediaAnnotation
interface and may be filled with the specific attributes.
mediaAnnotation = image.getMediaProperty(["title"], "", "", ""); if (noErrorStatus(mediaAnnotation[0].statusCode) == true) { ... } /** Resulting in: * [ { "Title" : { * "propertyName" : "title", * "value" : "Gone with the Wind", * "language" : "en-us", * "sourceFormat" : "mpeg7", * "fragmentIdentifier" : "http://www.example.com/video.ogv#t=10,20", * "mappingType" : "Exact match", * "statusCode" : 200 * } * } ]
This section describes the different properties that can be requested
through the MediaResource.getMediaProperty()
operation. When
invoking this operation, objects implementing the MediaAnnotation
interface are returned that represent the specified property. All properties
are represented with an interface inherited from the
MediaAnnotation
interface (following the design guidelines
described above).
Several of the following return type interfaces can hold the value of the property as both URI (i.e., a pointer to a controlled vocabulary) or as free text. The URI is preferred, and the respective attribute of the return value shall be filled whenever possible (i.e., when the information is included in or can be constructed from the source metadata).
In the following, for each property, a (synchronous) JavaScript
example illustrates the usage of the property specific attributes. In any case,
the genereal attributes of the MediaAnnotation
interface could be
also requested.
When the MediaResource.getMediaProperty
operation is invoked
with "identifier" as a value of the propertyName
parameter, an
object implementing the Identifier
interface is returned
representing the identifier property (defined in the Ontology for Media Resources 1.0
specification).
interface Identifier : MediaAnnotation
{
attribute DOMString identifierLink;
};
identifierLink
of type
DOMStringid = image.getMediaProperty(["identifier"]); /** Resulting in: * [ { "Identifier" : { * "propertyName" : "identifier", * "identifierLink" : "urn:uuid:36a87260-1102-11df-8a39-0800200c9a66", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "title" as a value of the propertyName
parameter, an object
implementing the Title
interface is returned representing the
title property (defined in the Ontology for Media Resources 1.0
specification).
interface Title : MediaAnnotation
{
attribute DOMString titleLabel;
attribute DOMString typeLink;
attribute DOMString typeLabel;
};
title = song.getMediaProperty(["title"]); /** Resulting in: * [ { "Title" : { * "propertyName" : "title", * "titleLabel" : "Artificial Horizon" , * "typeLink" : "http://www.ebu.ch/metadata/cs/ebu_ObjectTypeCodeCS.xml#21", * "typeLabel" : "Album title", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "language" as a value of the propertyName
parameter, an
object implementing the Language
interface is returned
representing the language property (defined in the Ontology for Media Resources 1.0
specification).
interface Language : MediaAnnotation
{
attribute DOMString languageLink;
attribute DOMString languageLabel;
};
languageLabel
of type DOMStringgetMediaProperty
operation. Recommended best practice is to use BCP 47 [BCP47].
languageLink
of type DOMStringlanguage = video.getMediaProperty(["language"]); /** Resulting in: * [ { "Language" : { * "propertyName" : "language", * "languageLabel" : "en-us", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "locator" as a value of the propertyName
parameter, an object
implementing the Locator
interface is returned representing the
locator property (defined in the Ontology for Media Resources 1.0
specification).
interface Locator : MediaAnnotation
{
attribute DOMString locatorLink;
};
locatorLink
of type DOMStringlocator = image.getMediaProperty(["locator"]); /** Resulting in: * [ { "Locator" : { * "propertyName" : "locator", * "locatorLink" : "http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "contributor" as a value of the propertyName
parameter, an
object implementing the Contributor
interface is returned
representing the contributor property (defined in the Ontology for Media Resources 1.0
specification).
interface Contributor : MediaAnnotation
{
attribute DOMString contributorLink;
attribute DOMString contributorLabel;
attribute DOMString roleLink;
attribute DOMString roleLabel;
};
contributorLabel
of
type DOMStringcontributorLink
of
type DOMStringroleLabel
of type DOMStringroleLink
of type DOMStringcontributor = video.getMediaProperty(["contributor"]); /** Resulting in: * [ { "Contributor" : { * "propertyName" : "contributor", * "contributorLink" : "http://en.wikipedia.org/wiki/Tim_Burton", * "contributorLabel" : "Tim Burton", * "roleLink" : "http://www.imdb.com/name/nm0000318/", * "roleLabel" : "director", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "creator" as a value of the propertyName
parameter, an object
implementing the Creator
interface is returned representing the
creator property (defined in the Ontology for Media Resources 1.0
specification).
interface Creator : MediaAnnotation
{
attribute DOMString creatorLink;
attribute DOMString creatorLabel;
attribute DOMString roleLink;
attribute DOMString roleLabel;
};
creatorLabel
of type DOMStringcreatorLink
of type DOMStringroleLabel
of type DOMStringroleLink
of type DOMStringcreator = video.getMediaProperty(["creator"]); /** Resulting in: * [ { "Creator" : { * "propertyName" : "creator", * "creatorLink" : "http://dbpedia.org/resource/William_Shakespeare", * "creatorLabel" : "William Shakespeare", * "roleLink" : "http://www.ebu.ch/metadata/cs/ebu_RoleCodeCS.xml#22.5", * "roleLabel" : "playwright", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "date" as a value of the propertyName
parameter, an object
implementing the Date
interface is returned representing the
date property (defined in the Ontology for Media Resources 1.0
specification). This property has been renamed from "Date" into "MADate" since
the appearance of naming conflicts is possible in web applications.
interface MADate : MediaAnnotation
{
attribute DOMString date;
attribute DOMString typeLink;
attribute DOMString typeLabel;
};
date
of type DOMStringtypeLabel
of type DOMStringtypeLink
of type DOMStringmaDate = video.getMediaProperty(["date"]); /** Resulting in: * [ { "MADate" : { * "propertyName" : "date", * "date": "2009-06-26T15:30:00", * "typeLink" : "urn:smpte:ul:06.0E.2B.34.01.01.01.02.07.02.01.10.02.03.00.00", * "typeLabel" : "modification date", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "location" as a value of the propertyName
parameter, an
object implementing the Location
interface is returned
representing the location property (defined in the Ontology for Media Resources 1.0
specification).
interface Location : MediaAnnotation
{
attribute DOMString locationLink;
attribute DOMString locationLabel;
attribute double longitude;
attribute double latitude;
attribute double altitude;
attribute DOMString coordinateSystemLabel;
attribute DOMString coordinateSystemLink;
};
altitude
of type doublecoordiateSystem
attribute
(default is WGS84).
coordinateSystemLabel
of type DOMStringcoordinateSystemLink
of type DOMStringlatitude
of type doublecoordiateSystem
attribute
(default is WGS84).
locationLabel
of type DOMStringlocationLink
of type DOMStringlongitude
of type doublecoordiateSystem
attribute
(default is WGS84).
location = video.getMediaProperty(["location"]); /** Resulting in: * [ { "Location" : { * "propertyName" : "location", * "locationLink" : "http://en.wikipedia.org/wiki/San_Jose,_California", * "locationLabel" : "San Jose", * "longitude" : 37.33986481118008, * "latitude" : -121.88507080078125, * "altitude" : 0, * "coordinateSystemLabel" : "WGS84", * "coordinateSystemLink" : "http://www.w3.org/2003/01/geo/wgs84_pos#Point", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "description" as a value of the propertyName
parameter, an
object implementing the Description
interface is returned
representing the description property (defined in the Ontology for Media Resources 1.0
specification).
interface Description : MediaAnnotation
{
attribute DOMString descriptionLabel;
};
descriptionLabel
of
type DOMStringdescription = image.getMediaProperty(["description"]); /** Resulting in: * [ { "Description" : { * "propertyName" : "description", * "descriptionLabel" : "Group picture of the W3C MAWG at the F2F meeting in Stockholm.", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "keyword" as a value of the propertyName
parameter, an object
implementing the Keyword
interface is returned representing the
keyword property (defined in the Ontology for Media Resources 1.0
specification).
interface Keyword : MediaAnnotation
{
attribute DOMString keywordLabel;
attribute DOMString keywordLink;
};
keyword = image.getMediaProperty(["keyword"]); /** Resulting in: * [ { "Keyword" : { * "propertyName" : "keyword", * "keywordLabel" : "meeting with people from outside the organisation", * "keywordLink" : "http://sw.opencyc.org/2008/06/10/concept/en/MeetingWithOrganizationalOutsiders", * "statusCode" : 200 * } * }, * { "Keyword" : { * "propertyName" : "keyword", * "keywordLabel" : "standardisation", * "keywordLink" : "http://purl.org/vocabularies/princeton/wn30/synset-standardization-noun-1", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "genre" as a value of the propertyName
parameter, an object
implementing the Genre
interface is returned representing the
genre property (defined in the Ontology for Media Resources 1.0
specification).
interface Genre : MediaAnnotation
{
attribute DOMString genreLabel;
attribute DOMString genreLink;
};
genre = image.getMediaProperty(["genre"]); /** Resulting in: * [ { "Genre" : { * "propertyName" : "genre", * "genreLabel" : "Sports", * "genreLink" : "http://www.ebu.ch/metadata/cs/ebu_ContentGenreCS.xml#3.1.1.9" * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "rating" as a value of the propertyName
parameter, an object
implementing the Rating
interface is returned representing the
rating property (defined in the Ontology for Media Resources 1.0
specification).
interface Rating : MediaAnnotation
{
attribute double ratingValue;
attribute DOMString ratingSystemLabel;
attribute DOMString ratingSystemLink;
attribute double minimum;
attribute double maximum;
};
maximum
of type doubleminimum
of type doubleratingSystemLabel
of type
DOMStringratingSystemLink
of type
DOMStringratingValue
of type doublerating = image.getMediaProperty(["rating"]); /** Resulting in: * [ { "Rating" : { * "propertyName" : "rating", * "ratingValue" : 10.0, * "ratingSystemLabel" : "John Doe", * "ratingSystemLink" : "http://individuals.example.com/JohnDoe", * "minimum" : 0, * "maximum" : 10.0, * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "relation" as a value of the propertyName
parameter, an
object implementing the Relation
interface is returned
representing the relation property (defined in the Ontology for Media Resources 1.0
specification).
interface Relation : MediaAnnotation
{
attribute DOMString targetLink;
attribute DOMString targetLabel;
attribute DOMString typeLink;
attribute DOMString typeLabel;
};
targetLabel
of type DOMStringtargetLink
of type DOMStringtypeLabel
of type DOMStringtypeLink
of type DOMStringrelation = image.getMediaProperty(["relation"]); /** Resulting in: * [ { "Relation" : { * "propertyName" : "relation", * "targetLink" : "http://www.w3.org/2008/WebVideo/Annotations/wiki/Image:MAWG-Stockholm-20090626_thumb.JPG", * "targetLabel" : "Group picture of MAWG in Stockholm", * "typeLink" : "http://www.ebu.ch/metadata/cs/ebu_HowRelatedCS.xml#19", * "typeLabel" : "thumbnail", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "collection" as a value of the propertyName
parameter, an
object implementing the Collection
interface is returned
representing the collection property (defined in the Ontology for Media Resources 1.0
specification).
interface Collection : MediaAnnotation
{
attribute DOMString collectionLink;
attribute DOMString collectionLabel;
};
collectionLabel
of type
DOMStringcollectionLink
of type
DOMStringcollection = image.getMediaProperty(["collection"]); /** Resulting in: * [ { "Collection" : { * "propertyName" : "collection", * "collectionLink" : "http://individuals.example.com/JohnDoe/myWorkPictures/", * "collectionLabel" : "My Work Pictures", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "copyright" as a value of the propertyName
parameter, an
object implementing the Copyright
interface is returned
representing the copyright property (defined in the Ontology for Media Resources 1.0
specification).
interface Copyright : MediaAnnotation
{
attribute DOMString copyrightLabel;
attribute DOMString holderLabel;
attribute DOMString holderLink;
};
copyrightLabel
of type
DOMStringholderLabel
of type DOMStringholderLink
of type DOMStringcopyright = image.getMediaProperty(["copyright"]); /** Resulting in: * [ { "Copyright" : { * "propertyName" : "copyright", * "copyrightLabel" : "All images in the collection are copyrighted by John Doe.", * "holderLabel" : "John Doe", * "holderLink" : "http://individuals.example.com/JohnDoe", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "policy" as a value of the propertyName
parameter, an object
implementing the Policy
interface is returned representing the
policy property (defined in the Ontology for Media Resources 1.0
specification).
interface Policy : MediaAnnotation
{
attribute DOMString statementLink;
attribute DOMString statementLabel;
attribute DOMString typeLink;
attribute DOMString typeLabel;
};
statementLabel
of type DOMStringstatementLink
of type DOMStringtypeLabel
of type DOMStringtypeLink
of type DOMStringpolicy = image.getMediaProperty(["policy"]); /** Resulting in: * [ { "Policy" : { * "propertyName" : "policy", * "statementLink" : "http://creativecommons.org/licenses/by/2.5/", * "statementLabel" : "Attribution 2.5 Generic (CC BY 2.5)", * "typeLabel" : "license", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "publisher" as a value of the propertyName
parameter, an
object implementing the Publisher
interface is returned
representing the publisher property (defined in the Ontology for Media Resources 1.0
specification).
interface Publisher : MediaAnnotation
{
attribute DOMString publisherLink;
attribute DOMString publisherLabel;
};
publisher = image.getMediaProperty(["publisher"]); /** Resulting in: * [ { "Publisher" : { * "propertyName" : "publisher", * "publisherLabel" : "ACME", * "publisherLink" : "http://company.example.com/ACME", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "targetAudience" as a value of the propertyName
parameter, an
object implementing the TargetAudience
interface is returned
representing the targetAudience property (defined in the Ontology for Media Resources 1.0
specification).
interface TargetAudience : MediaAnnotation
{
attribute DOMString audienceLink;
attribute DOMString audienceLabel;
attribute DOMString classificationSystemLink;
attribute DOMString classificationSystemLabel;
};
audienceLabel
of type
DOMStringaudienceLink
of type
DOMStringclassificationSystemLabel
of type DOMStringclassificationSystemLink
of type DOMStringtargetAudience = image.getMediaProperty(["targetAudience"]); /** Resulting in: * [ { "TargetAudience" : { * "propertyName" : "targetAudience", * "audienceLink" : "http://www.mpaa.org/ratings/what-each-rating-means#NC-17", * "audienceLabel" : "No One 17 and Under Admitted", * "classificationSystemLink" : "http://www.mpaa.org/ratings", * "classificationSystemLabel" : "MPAA", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "fragment" as a value of the propertyName
parameter, an
object implementing the Fragment
interface is returned
representing the fragment property (defined in the Ontology for Media Resources 1.0
specification).
interface Fragment : MediaAnnotation
{
attribute DOMString identifier;
attribute DOMString roleLink;
attribute DOMString roleLabel;
};
identifier
of type DOMStringroleLabel
of type DOMStringgetMediaProperty
operation.
roleLink
of type DOMStringgetMediaProperty
operation.
fragment = movie.getMediaProperty(["fragment"]); /** Resulting in: * [ { "Fragment" : { * "propertyName" : "fragment", * "identifier" : "http://www.example.com/video.ogv#t=10,20", * "roleLabel" : "chapter", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "namedFragment" as a value of the propertyName
parameter, an
object implementing the NamedFragment
interface is returned
representing the namedFragment property (defined in the Ontology for Media Resources 1.0
specification).
interface NamedFragment : MediaAnnotation
{
attribute DOMString identifier;
attribute DOMString label;
};
namedFragment = movie.getMediaProperty(["namedFragment"]); /** Resulting in: * [ { "NamedFragment" : { * "propertyName" : "namedFragment", * "identifier" : "http://www.example.com/video.ogv#t=30,35", * "label" : "kissScene", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "frameSize" as a value of the propertyName
parameter, an
object implementing the FrameSize
interface is returned
representing the frameSize property (defined in the Ontology for Media Resources 1.0
specification).
interface FrameSize : MediaAnnotation
{
attribute double width;
attribute double height;
attribute DOMString unit;
};
height
of type doubleunit
of type DOMStringwidth
of type doubleframeSize = image.getMediaProperty(["frameSize"]); /** Resulting in: * [ { "FrameSize" : { * "propertyName" : "framesize", * "width" : 3072, * "height" : 2304, * "unit" : "pixels", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "compression" as a value of the propertyName
parameter, an
object implementing the Compression
interface is returned
representing the compression property (defined in the Ontology for Media Resources 1.0
specification).
interface FrameSize : MediaAnnotation
{
attribute DOMString compressionLink;
attribute DOMString compressionLabel;
};
compression = video.getMediaProperty(["compression"]); /** Resulting in: * [ { "Compression" : { * "propertyName" : "compression", * "compressionLabel" : "H.264/AVC", * "compressionLink" : "urn:example-org:codingnames2010#ITU-H264", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "duration" as a value of the propertyName
parameter, an
object implementing the Duration
interface is returned
representing the duration property (defined in the Ontology for Media Resources 1.0
specification).
interface Duration : MediaAnnotation
{
attribute double duration;
};
duration
of type doubleduration = video.getMediaProperty(["duration"]); /** Resulting in: * [ { "Duration" : { * "propertyName" : "duration", * "duration" : 3600, * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "format" as a value of the propertyName
parameter, an object
implementing the Format
interface is returned representing the
format property (defined in the Ontology for Media Resources 1.0
specification).
interface Format : MediaAnnotation
{
attribute DOMString formatLink;
attribute DOMString formatLabel;
};
format = image.getMediaProperty(["format"]); /** Resulting in: * [ { "Format" : { * "propertyName" : "format", * "formatLabel" : "image/jpeg", * "formatLink" : "http://dbpedia.org/resource/JPEG", * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "samplingRate" as a value of the propertyName
parameter, an
object implementing the SamplingRate
interface is returned
representing the samplingRate property (defined in the Ontology for Media Resources 1.0
specification).
interface SamplingRate : MediaAnnotation
{
attribute double samplingRate;
};
samplingRate
of type
doublesamplingrate = audio.getMediaProperty(["samplingRate"]); /** Resulting in: * [ { "SamplingRate" : { * "propertyName" : "samplingRate", * "samplingRate" : 44100, * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "frameRate" as a value of the propertyName
parameter, an
object implementing the FrameRate
interface is returned
representing the frameRate property (defined in the Ontology for Media Resources 1.0
specification).
interface FrameRate : MediaAnnotation
{
attribute double frameRate;
};
frameRate
of type doubleframerate = video.getMediaProperty(["frameRate"]); /** Resulting in: * [ { "FrameRate" : { * "propertyName" : "frameRate", * "frameRate" : 30, * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "averageBitRate" as a value of the propertyName
parameter, an
object implementing the AverageBitRate
interface is returned
representing the averageBitRate property (defined in the Ontology for Media Resources 1.0
specification).
interface AverageBitRate : MediaAnnotation
{
attribute double averageBitRate;
};
averageBitRate
of
type doublebitrate = video.getMediaProperty(["averageBitRate"]); /** Resulting in: * [ { "AverageBitRate" : { * "propertyName" : "averageBitRate", * "averageBitRate" : 45.06, * "statusCode" : 200 * } * } ] */
When the MediaResource.getMediaProperty
operation is invoked
with "numTracks" as a value of the propertyName
parameter, an
object implementing the NumTracks
interface is returned
representing the numTracks property (defined in the Ontology for Media Resources 1.0
specification).
interface NumTracks : MediaAnnotation
{
attribute short number;
attribute DOMString typeString;
};
numTracks = video.getMediaProperty(["numTracks"]); /** Resulting in: * [ { "NumTracks" : { * "propertyName" : "numTracks", * "number" : 2, * "typeString" : "audio", * "statusCode" : 200 * } * } ] */
MetadataSource
interfaceMetadataSource
interface is used to identify other metadata
sources.
interface MetadataSource {
attribute DOMString metadataSource;
attribute DOMString sourceFormat;
};
metadataSource
of
type DOMStringsourceFormat
of type
DOMStringmetadataSources = new MetadataSource("http://www.w3.org/2008/WebVideo/Annotations/drafts/metadata_formats/DC_example1.xml","dc");
This section introduces a set of status codes for the defined API to indicate the system behavior. As described in section 4.4, the status code is returned as one of the attributes of the MediaAnnotation object returned by a method call to the API. These status codes are used on the API level, and applied to either client side or server side implementations.
Later versions of this document may include additional status codes.
Numerical Code | Textual Description | Example |
---|---|---|
200 | OK | property delivered correctly |
204 | No Content | property retrieved without content |
206 | Partial Content | only a subset of the available data stored in the result set |
400 | Bad Request | syntactical error |
404 | Not Found | the queries resource is not found |
415 | Unsupported Media Type | get duration call on an image data store |
462 | Property not defined in Source Format | location is not defined in MediaRSS |
500 | Internal Server Error | internal library (e.g., extractor) crashes |
562 | Property not supported | a subset of properties implemented |
This part illustrates some examples how to use this API using JavaScript in
actual implementations. Moreover, in these examples it is assumed that the
implementation of this API knows where to find the metadata that corresponds to
a specific media resource (if necessary the location of the metadata can be
configured by the use of the MetadataSource
interface). The
implementation should provide the mappings of
different metadata formats to the core
properties of the Ontology for
Media Resources 1.0 specification.
//search the video array for the one with title "Apocalypse now" for (var i = 0; i < mediaResourceVideoArray.length; i++) { //request for the titles of the video, the variable "titles" //will be filled with an array of MediaAnnotation objects. titles = mediaResourceVideoArray[i].getMediaProperty(["title"], "", "", ""); //check if the request is finished correctly if (noErrorStatus(titles[0].statusCode) == true) { for (var j = 0; j < titles.length; j++) { //check if the title matches if (titles[j].titleLabel == "Apocalypse Now") { //request for the director of the video, the variable "results" //will be filled with an array of MediaAnnotation objects. tempResults = mediaResourceVideoArray[i].getMediaProperty(["contributor"], "", "", ""); for (var k = 0; k < tempResults.length; k++) { if (tempResults[i].roleLabel == "director") { result = tempResults[i]; break; } } } } } } /** Resulting in: * [ { "Contributor" : { * "propertyName" : "contributor", * "value" : "Francis Ford Coppola", * ..., * "statusCode" = 200 * } * } ] */
//get the id of the second song using the fragments property tracks = albumMediaResource.getMediaProperty(["fragment"], "", "", ""); trackIdentifier = tracks[1].identifier; //use this identifier to get the mediaResource object that represents the track mediaResource = new MediaResource(); if (mediaResource.getSupportedModes() == 2 || mediaResource.getSupportedModes() == 3) { syncMediaResource = mediaResource.createMediaResource(trackIdentifier, new Array(), 2); } //get the title of the track title = syncMediaResource.getMediaProperty(["title"], "", "", ""); /** Resulting in: * [ { "Title" : { * "propertyName" : "title", * "value" : "I Still Haven't Found What I'm Looking For", * ..., * "statusCode" = 200 * } * } ] */
genre = movie.getMediaProperty(["genre"], "", "", "en-us"); /** Resulting in: * [ { "Genre" : { * "propertyName" : "genre", * "value" : "Action", * ..., * "statusCode" = 200 * } * }, * { "Genre" : { * "propertyName" : "genre", * "value" : "Drama", * ..., * "statusCode" = 200 * } * }, * { ... * } ] */
This part illustrates how this API could be implemented using web services. Note that, Web IDL currently does not provide bindings for web services. The given examples correspond to the examples given in Section 4.5 for each property.
Request: http://example.com/my-media-resource/?getOriginalMetadata=DC
Response (JSON format):
[ { "statusCode" : "200" }, {"originalMetadata" : "<?xml version='1.0'?><metadata xmlns='http://example.org/myapp/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:schemaLocation='http://example.org/myapp/ http://example.org/myapp/schema.xsd' xmlns:dc='http://purl.org/dc/elements/1.1/'><dc:title>DC title</dc:title></metadata>"} ]
The following examples illustrate how to request values for the different properties.
Request: http://example.com/my-media-resource/?ma-query=identifier
Response (JSON format):
[ { "Identifier" : { "propertyName" : "identifier", "identifierLink" : "urn:uuid:36a87260-1102-11df-8a39-0800200c9a66", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=title
Response (JSON format):
[ { "Title" : { "propertyName" : "title", "value" : "Artificial Horizon", "typeLink" : "http://www.ebu.ch/metadata/cs/ebu_ObjectTypeCodeCS.xml#21", "typeLabel" : "Album title", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=language
Response (JSON format):
[ { "Language" : { "propertyName" : "language", "languageLabel" : "en-us", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=locator
Response (JSON format):
[ { "Locator" : { "propertyName" : "locator", "locatorLink" : "http://www.w3.org/2008/WebVideo/Annotations/wiki/images/9/93/MAWG-Stockholm-20090626.JPG", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=contributor
Response (JSON format):
[ { "Contributor" : { "propertyName" : "contributor", "contributorLink" : "http://en.wikipedia.org/wiki/Tim_Burton", "contributorLabel" : "Tim Burton", "roleLink" : "http://www.imdb.com/name/nm0000318/", "roleLabel" : "director", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=creator
Response (JSON format):
[ { "Creator" : { "propertyName" : "creator", "creatorLink" : "http://dbpedia.org/resource/William_Shakespeare", "creatorLabel" : "William Shakespeare", "roleLink" : "http://www.ebu.ch/metadata/cs/ebu_RoleCodeCS.xml#22.5", "roleLabel" : "playwright", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=date
Response (JSON format):
[ { "MADate" : { "propertyName" : "date", "date": "2009-06-26T15:30:00", "typeLink" : "urn:smpte:ul:06.0E.2B.34.01.01.01.02.07.02.01.10.02.03.00.00", "typeLabel" : "modification date", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=location
Response (JSON format):
[ { "Location" : { "propertyName" : "location", "locationLink" : "http://en.wikipedia.org/wiki/San_Jose,_California", "locationLabel" : "San Jose", "longitude" : 37.33986481118008, "latitude" : -121.88507080078125, "altitude" : 0, "coordinateSystemLabel" : "WGS84", "coordinateSystemLink" : "http://www.w3.org/2003/01/geo/wgs84_pos#Point", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=description
Response (JSON format):
[ { "Description" : { "propertyName" : "description", "descriptionLabel" : "Group picture of the W3C MAWG at the F2F meeting in Stockholm.", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=keyword
Response (JSON format):
[ { "Keyword" : { "propertyName" : "keyword", "keywordLabel" : "meeting with people from outside the organisation", "keywordLink" : "http://sw.opencyc.org/2008/06/10/concept/en/MeetingWithOrganizationalOutsiders", "statusCode" : 200 } }, { "Keyword" : { "propertyName" : "keyword", "keywordLabel" : "standardisation", "keywordLink" : "http://purl.org/vocabularies/princeton/wn30/synset-standardization-noun-1", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=genre
Response (JSON format):
[ { "Genre" : { "propertyName" : "genre", "genreLabel" : "Sports", "genreLink" : "http://www.ebu.ch/metadata/cs/ebu_ContentGenreCS.xml#3.1.1.9", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=rating
Response (JSON format):
[ { "Rating" : { "propertyName" : "rating", "ratingValue" : 10.0, "ratingSystemLabel" : "John Doe", "ratingSystemLink" : "http://individuals.example.com/JohnDoe", "minimum" : 0, "maximum" : 10.0, "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=relation
Response (JSON format):
[ { "Relation" : { "propertyName" : "relation", "targetLink" : "http://www.w3.org/2008/WebVideo/Annotations/wiki/Image:MAWG-Stockholm-20090626_thumb.JPG", "targetLabel" : "Group picture of MAWG in Stockholm", "typeLink" : "http://www.ebu.ch/metadata/cs/ebu_HowRelatedCS.xml#19", "typeLabel" : "thumbnail", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=collection
Response (JSON format):
[ { "Collection" : { "propertyName" : "collection", "collectionLink" : "http://individuals.example.com/JohnDoe/myWorkPictures/", "collectionLabel" : "My Work Pictures", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=copyright
Response (JSON format):
[ { "Copyright" : { "propertyName" : "copyright", "copyrightLabel" : "All images in the collection are copyrighted by John Doe.", "holderLabel" : "John Doe", "holderLink" : "http://individuals.example.com/JohnDoe", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=policy
Response (JSON format):
[ { "Policy" : { "propertyName" : "policy", "statementLink" : "http://creativecommons.org/licenses/by/2.5/", "statementLabel" : "Attribution 2.5 Generic (CC BY 2.5)", "typeLabel" : "license", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=publisher
Response (JSON format):
[ { "Publisher" : { "propertyName" : "publisher", "publisherLabel" : "ACME", "publisherLink" : "http://company.example.com/ACME", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=targetAudience
Response (JSON format):
[ { "TargetAudience" : { "propertyName" : "targetAudience", "audienceLink" : "http://www.mpaa.org/ratings/what-each-rating-means#NC-17", "audienceLabel" : "No One 17 and Under Admitted", "classificationSystemLink" : "http://www.mpaa.org/ratings", "classificationSystemLabel" : "MPAA", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=fragment
Response (JSON format):
[ { "Fragment" : { "propertyName" : "fragment", "identifier" : "http://www.example.com/video.ogv#t=10,20", "roleLabel" : "chapter", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=namedFragment
Response (JSON format):
[ { "NamedFragment" : { "propertyName" : "namedFragment", "label" : "kissScene", "identifier" : "http://www.example.com/video.ogv#t=30,35", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=frameSize
Response (JSON format):
[ { "FrameSize" : { "propertyName" : "framesize", "width" : 3072, "height" : 2304, "unit" : "pixels", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=compression
Response (JSON format):
[ { "Compression" : { "propertyName" : "compression", "compressionLabel" : "H.264/AVC", "urn:example-org:codingnames2010#ITU-H264", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=duration
Response (JSON format):
[ { "Duration" : { "propertyName" : "duration", "duration" : 3600, "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=format
Response (JSON format):
[ { "Format" : { "propertyName" : "format", "formatLabel" : "image/jpeg", "formatLink" : "http://dbpedia.org/resource/JPEG", "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=samplingRate
Response (JSON format):
[ { "SamplingRate" : { "propertyName" : "samplingRate", "samplingRate" : 44100, "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=frameRate
Response (JSON format):
[ { "FrameRate" : { "propertyName" : "frameRate", "frameRate" : 30, "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=averageBitRate
Response (JSON format):
[ { "AverageBitRate" : { "propertyName" : "averageBitRate", "averageBitRate" : 45.06, "statusCode" : 200 } } ]
Request: http://example.com/my-media-resource/?ma-query=numTracks
Response (JSON format):
[ { "NumTracks" : { "propertyName" : "numTracks", "number" : 2, "typeString" : "audio", "statusCode" : 200 } } ]
This specification defines a API to access metadata information related to media resources on the Web. These APIs will provide means for requesting metadata information, which can already be accessed in one or different formats, either as separate document or embedded in media resources. As such, this API introduces no additional security issue.
One should nevertheless note that some metadata could be used to access personal information about someone without declaration of agreement. For example, temporal and geographic information about a media resource could indirectly provide information about its creator.
There are related activities and technical documents in W3C working on this topics, such as Policy Requirements [POLICY-REQS] in DAP WG, ODRL 1.1 [ODRL11], P3P 1.1 [P3P11] and PLING Wiki [PLING-WIKI].
Follow this link to download the WebIDL description as IDL file.
module mawg { interface MediaResource { short getSupportedModes(); MediaResource createMediaResource(in DOMString mediaResource, in optional MetadataSource[] metadataSources, in optional short mode); }; interface AsyncMediaResource : MediaResource { void getMediaProperty(in DOMString[] propertyNames, in PropertyCallback successCallback, in ErrorCallback errorCallback, in optional DOMString fragment, in optional DOMString sourceFormat, in optional DOMString language ); void getOriginalMetadata (in DOMString sourceFormat, in MetadataCallback successCallback, in ErrorCallback errorCallback); }; interface PropertyCallback { void handleEvent (in MediaAnnotation[] mediaAnnotations); }; interface MetadataCallback { void handleEvent (in DOMString[] metadata); }; interface ErrorCallback { void handleEvent (in DOMString errorStatus); }; interface SyncMediaResource : MediaResource { MediaAnnotation[] getMediaProperty(in DOMString[] propertyNames, in optional DOMString fragment, in optional DOMString sourceFormat, in optional DOMString language); DOMString[] getOriginalMetadata (in DOMString sourceFormat); }; interface MetadataSource { attribute DOMString metadataSource; attribute DOMString sourceFormat; }; interface MediaAnnotation { attribute DOMString propertyName; attribute DOMString value; attribute DOMString language; attribute DOMString sourceFormat; attribute DOMString fragmentIdentifier; attribute DOMString mappingType; attribute short statusCode; }; interface Identifier : MediaAnnotation { attribute DOMString identifierLink; }; interface Title : MediaAnnotation { attribute DOMString titleLabel; attribute DOMString typeLink; attribute DOMString typeLabel; }; interface Language : MediaAnnotation { attribute DOMString languageLink; attribute DOMString languageLabel; }; interface Locator : MediaAnnotation { attribute DOMString locatorLink; }; interface Contributor : MediaAnnotation { attribute DOMString contributorLink; attribute DOMString contributorLabel; attribute DOMString roleLink; attribute DOMString roleLabel; }; interface Creator : MediaAnnotation { attribute DOMString creatorLink; attribute DOMString creatorLabel; attribute DOMString roleLink; attribute DOMString roleLabel; }; interface MADate : MediaAnnotation { attribute DOMString date; attribute DOMString typeLink; attribute DOMString typeLabel; }; interface Location : MediaAnnotation { attribute DOMString locationLink; attribute DOMString locationLabel; attribute double longitude; attribute double latitude; attribute double altitude; attribute DOMString coordinateSystemLabel; attribute DOMString coordinateSystemLink; }; interface Description : MediaAnnotation { attribute DOMString descriptionLabel; }; interface Keyword : MediaAnnotation { attribute DOMString keywordLink; attribute DOMString keywordLabel; }; interface Genre : MediaAnnotation { attribute DOMString genreLink; attribute DOMString genreLabel; }; interface Rating : MediaAnnotation { attribute double ratingValue; attribute DOMString ratingSystemLink; attribute DOMString ratingSystemLabel; attribute double min; attribute double max; }; interface Relation : MediaAnnotation { attribute DOMString targetLink; attribute DOMString targetLabel; attribute DOMString typeLink; attribute DOMString typeLabel; }; interface Collection : MediaAnnotation { attribute DOMString collectionLink; attribute DOMString collectionLabel; }; interface Copyright : MediaAnnotation { attribute DOMString copyrightLabel; attribute DOMString holderLink; attribute DOMString holderLabel; }; interface Policy : MediaAnnotation { attribute DOMString statementLink; attribute DOMString statementLabel; attribute DOMString typeLink; attribute DOMString typeLabel; }; interface Publisher : MediaAnnotation { attribute DOMString publisherLink; attribute DOMString publisherLabel; }; interface TargetAudience : MediaAnnotation { attribute DOMString audienceLink; attribute DOMString audienceLabel; attribute DOMString classificationSystemLink; attribute DOMString classificationSystemLabel; }; interface Fragment : MediaAnnotation { attribute DOMString identifier; attribute DOMString roleLink; attribute DOMString roleLabel; }; interface NamedFragment : MediaAnnotation { attribute DOMString identifier; attribute DOMString label; }; interface FrameSize : MediaAnnotation { attribute double width; attribute double height; attribute DOMString unit; }; interface Compression : MediaAnnotation { attribute DOMString compressionLink; attribute DOMString compressionLabel; }; interface Duration : MediaAnnotation { attribute double duration; }; interface Format : MediaAnnotation { attribute DOMString formatLink; attribute DOMString formatLabel; }; interface SamplingRate : MediaAnnotation { attribute double samplingRate; }; interface FrameRate : MediaAnnotation { attribute double frameRate; }; interface AverageBitRate : MediaAnnotation { attribute double averageBitRate; }; interface NumTracks : MediaAnnotation { attribute short number; attribute DOMString typeString; }; };
Note: The following subsections lists all significant changes applied to the API for Media Resources 1.0 specification received in LC.
-- General changes ---
---[LC 2406] 2001-09-10 ---
---[LC 2410] 2001-09-10 ---
---[LC 2419] 2001-09-10 ---
---[LC 2394] 2001-09-10 ---
The following subsection lists all significant changes applied to the API for Media Resources 1.0 specification. These have been decided during the 10th Face-to-face meeting hosted by Apple in Silicon Valley, Ca, USA.
The following subsection lists all significant changes applied to the API for Media Resources 1.0 specification. These have been decided during the 12th Face-to-face meeting hosted by JOANNEUM, Graz, Austria.
This document is the work of the W3C Media Annotations Working Group.
Members of the Working Group are (at the time of writing, and by alphabetical order): Werner Bailer (JOANNEUM RESEARCH), Tobias Bürger ((public) Invited expert), Eric Carlson (Apple, Inc.), Pierre-Antoine Champin (Université de Lyon), Ashish Chawla ((public) Invited expert), Jaime Delgado (Universitat Politècnica de Catalunya), Jean-Pierre Evain ((public) Invited expert), Martin Höffernig (JOANNEUM RESEARCH), Philip Jägenstedt (Opera Software), Ralf Klamma ((public) Invited expert), WonSuk Lee (Samsung Electronics Co., Ltd.), Véronique Malaisé (Vrije Universiteit), Erik Mannens (IBBT), Hui Miao (Samsung Electronics Co., Ltd.), Thierry Michel (W3C/ERCIM), Frank Nack (University of Amsterdam), Soohong Daniel Park (Samsung Electronics Co., Ltd.), Silvia Pfeiffer (W3C Invited Experts), Chris Poppe (IBBT), Victor Rodríguez (Universitat Politècnica de Catalunya), Felix Sasaki (Potsdam University of Applied Sciences), David Singer (Apple, Inc.), Florian Stegmaier ((public) Invited expert), John Strassner ((public) Invited expert), Joakim Söderberg (ERICSSON), Mari Carmen Suárez-Figueroa ((public) Invited expert) Thai Wey Then (Apple, Inc.), Ruben Tous (Universitat Politècnica de Catalunya), Raphaël Troncy (EURECOM), Vassilis Tzouvaras (K-Space), Davy Van Deursen (IBBT).
The people who have contributed to discussions on public-media-annotation@w3.org are also gratefully acknowledged.