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         </Entry>
         </Entry>
     </ChannelList>
     </ChannelList>
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Note that the content of each metadata will be fully xml escaped (so metadata for a given id won't be byte-for-byte identical to that returned by Read).
 +
== SeekSecondAbsolute ==
== SeekSecondAbsolute ==
Seek to an absolute (seconds) position in the currently playing stream, retaining the existing TransportState.  Note that most radio streams are not seekable so this action is probably only applicable to a subset of tracks played via SetChannel that the Info service reports are seekable.
Seek to an absolute (seconds) position in the currently playing stream, retaining the existing TransportState.  Note that most radio streams are not seekable so this action is probably only applicable to a subset of tracks played via SetChannel that the Info service reports are seekable.

Revision as of 12:38, 12 June 2013

Contents

Architectural Overview

The Radio service primarily offers the means for controlling radio presets; it also offers an API to allow arbitrary URLs to be played. If a device’s Product service reports a source of type 'Radio', then the device that bears that Product service is guaranteed to also bear the Radio service.

Actions

Channel

Retrieve the values of the Uri and Metadata state variables.

ChannelsMax

Retrieve the value of the ChannelsMax state variable.

Id

Report the value of the Id state variable.

IdArray

Retrieve the value of the IdArray state variable.

IdArrayChanged

Check to see if the IdArray state variable has changed since gathering the specified IdArrayToken. This Token must have been previously collected from the IdArray action. This action is provided specifically for clients which do not use UPnP eventing.

Pause

Pause any currently playing radio stream. Should only be called when the Radio source is currently selected.

Play

Play any previously selected track (the last uri to be set via either SetChannel or SetId). Switches source to Radio if that wasn’t already selected.

ProtocolInfo

Retrieve the value of the ProtocolInfo state variable.

Read

Given a channel preset Id, retrieve its associated metadata. The metadata will be of the form 

   <DIDL-Lite xmlns:dc="http://purl.org/dc/elements/1.1/"
              xmlns:upnp="urn:schemas-upnp-org:metadata-1-0/upnp/"
              xmlns="urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/">
       <item id="" parentID="" restricted="True">
           <dc:title>[title]</dc:title>
           <res protocolInfo="*:*:*:*" bitrate="6000">[track url]</res>
           <upnp:albumArtURI>[image url]</upnp:albumArtURI>
           <upnp:class>object.item.audioItem</upnp:class>
       </item>
   </DIDL-Lite>

Note that additional elements may be present. The elements listed above are guaranteed to be present. The contents of all elements will be XML escaped.

ReadList

Given a space separated list of channel preset Ids, retrieve their associated metadata. The metadata will be of the form 

   <ChannelList>
       <Entry>
           <Id>[preset Id]</Id>
           <Metadata>[as for Read]</Metadata>
       </Entry>
       <Entry>
           ....
       </Entry>
   </ChannelList>

Note that the content of each metadata will be fully xml escaped (so metadata for a given id won't be byte-for-byte identical to that returned by Read).

SeekSecondAbsolute

Seek to an absolute (seconds) position in the currently playing stream, retaining the existing TransportState. Note that most radio streams are not seekable so this action is probably only applicable to a subset of tracks played via SetChannel that the Info service reports are seekable.

SeekSecondRelative

Seek to an position (in seconds) in the currently playing stream, relative to its current position, retaining the existing TransportState. Note that most radio streams are not seekable so this action is probably only applicable to a subset of tracks played via SetChannel that the Info service reports are seekable

SetChannel

Set the uri and metadata for a new track. Any currently playing track will be stopped. The new track will not play until the Play action is invoked. The Id state variable will be set to 0.

SetId

Set the preset id and uri for a new track. The uri should be parsed from the metadata returned by Read or ReadList. Any currently playing track will be stopped. The new track will not play until the Play action is invoked. The Id state variable will be updated to the newly specified preset id.

Stop

Stop any currently playing radio stream. Should only be called when the Radio source is currently selected

TransportState

Retrieve the value of the TransportState state variable.

State Variables

ChannelsMax

The maximum number of presets (and so the number of elements in IdArray). Read-only.

Id

The id of the currently selected preset (as set by the last call to SetId). Or 0 if no preset has ever been selected or SetChannel was called more recently than SetId.

IdArray

Base64-encoded array of 32-bit big endian unsigned integers. Will always be (ChannelsMax * 4) bytes long. Each id represents a preset id. A value of 0 implies that no preset is set for that slot.

Metadata

Metadata for the last track to be selected (via a call to either SetChannel or SetId).

ProtocolInfo

Audio formats and networking protocols supported by the device. Will be the same as reported by Playlist and AVTransport if these services are present. Read-only.

TransportState

One of Stopped, Playing, Paused or Buffering.

Uri

The last uri to be set (via a call to either SetChannel or SetId).

Technical Details 

   Domain  : av.openhome.org
   Name    : Radio
   Version : 1

Radio Service Description (XML) 

<?xml version="1.0"?>
<scpd xmlns="urn:schemas-upnp-org:service-1-0">
    <specVersion>
        <major>1</major>
        <minor>0</minor>
    </specVersion>
    <actionList>
        <action>
            <name>Play</name>
        </action>
        <action>
            <name>Pause</name>
        </action>
        <action>
            <name>Stop</name>
        </action>
        <action>
            <name>SeekSecondAbsolute</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>in</direction>
                    <relatedStateVariable>Absolute</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>SeekSecondRelative</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>in</direction>
                    <relatedStateVariable>Relative</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>Channel</name>
            <argumentList>
                <argument>
                    <name>Uri</name>
                    <direction>out</direction>
                    <relatedStateVariable>Uri</relatedStateVariable>
                </argument>
                <argument>
                    <name>Metadata</name>
                    <direction>out</direction>
                    <relatedStateVariable>Metadata</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>SetChannel</name>
            <argumentList>
                <argument>
                    <name>Uri</name>
                    <direction>in</direction>
                    <relatedStateVariable>Uri</relatedStateVariable>
                </argument>
                <argument>
                    <name>Metadata</name>
                    <direction>in</direction>
                    <relatedStateVariable>Metadata</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>TransportState</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>TransportState</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>Id</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>SetId</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Uri</name>
                    <direction>in</direction>
                    <relatedStateVariable>Uri</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>Read</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Metadata</name>
                    <direction>out</direction>
                    <relatedStateVariable>Metadata</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>ReadList</name>
            <argumentList>
                <argument>
                    <name>IdList</name>
                    <direction>in</direction>
                    <relatedStateVariable>IdList</relatedStateVariable>
                </argument>
                <argument>
                    <name>ChannelList</name>
                    <direction>out</direction>
                    <relatedStateVariable>ChannelList</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>IdArray</name>
            <argumentList>
                <argument>
                    <name>Token</name>
                    <direction>out</direction>
                    <relatedStateVariable>IdArrayToken</relatedStateVariable>
                </argument>
                <argument>
                    <name>Array</name>
                    <direction>out</direction>
                    <relatedStateVariable>IdArray</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>IdArrayChanged</name>
            <argumentList>
                <argument>
                    <name>Token</name>
                    <direction>in</direction>
                    <relatedStateVariable>IdArrayToken</relatedStateVariable>
                </argument>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>IdArrayChanged</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>ChannelsMax</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>ChannelsMax</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>ProtocolInfo</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>ProtocolInfo</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
    </actionList>
 
    <serviceStateTable>
        <stateVariable sendEvents="yes">
            <name>Uri</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>Metadata</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>TransportState</name>
            <dataType>string</dataType>
            <allowedValueList>
                <allowedValue>Stopped</allowedValue>
                <allowedValue>Playing</allowedValue>
                <allowedValue>Paused</allowedValue>
                <allowedValue>Buffering</allowedValue>
            </allowedValueList>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>Id</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>IdArray</name>
            <dataType>bin.base64</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>ChannelsMax</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>ProtocolInfo</name>
            <dataType>string</dataType>
        </stateVariable>        
        <stateVariable sendEvents="no">
            <name>Relative</name>
            <dataType>i4</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>Absolute</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>IdArrayToken</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>IdArrayChanged</name>
            <dataType>boolean</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>IdList</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>ChannelList</name>
            <dataType>string</dataType>
        </stateVariable>
    </serviceStateTable>
</scpd>
Retrieved from "http://wiki.openhome.org/wiki/Av:Developer:RadioService"