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Display.xml
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<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="docbook.xsl" type="text/xsl" ?>
<book version="5.0" xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:ns5="http://www.w3.org/1999/xhtml"
xmlns:ns4="http://www.w3.org/1998/Math/MathML"
xmlns:ns3="http://www.w3.org/2000/svg"
xmlns:ns="http://docbook.org/ns/docbook">
<info>
<title>Display Service Specification</title>
<titleabbrev>Display</titleabbrev>
<releaseinfo>2.3</releaseinfo>
<author>
<orgname>ONVIF™</orgname>
<uri>www.onvif.org</uri>
</author>
<pubdate>May, 2013</pubdate>
<mediaobject>
<imageobject>
<imagedata contentwidth="60mm" fileref="media/logo.png"/>
</imageobject>
</mediaobject>
<copyright>
<year>2008-2020</year>
<holder>ONVIF™ All rights reserved.</holder>
</copyright>
<legalnotice>
<para>Recipients of this document may copy, distribute, publish, or
display this document so long as this copyright notice, license and
disclaimer are retained with all copies of the document. No license is
granted to modify this document.</para>
<para>THIS DOCUMENT IS PROVIDED "AS IS," AND THE CORPORATION AND ITS
MEMBERS AND THEIR AFFILIATES, MAKE NO REPRESENTATIONS OR WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO, WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, OR
TITLE; THAT THE CONTENTS OF THIS DOCUMENT ARE SUITABLE FOR ANY PURPOSE;
OR THAT THE IMPLEMENTATION OF SUCH CONTENTS WILL NOT INFRINGE ANY
PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.</para>
<para>IN NO EVENT WILL THE CORPORATION OR ITS MEMBERS OR THEIR
AFFILIATES BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
PUNITIVE OR CONSEQUENTIAL DAMAGES, ARISING OUT OF OR RELATING TO ANY USE
OR DISTRIBUTION OF THIS DOCUMENT, WHETHER OR NOT (1) THE CORPORATION,
MEMBERS OR THEIR AFFILIATES HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES, OR (2) SUCH DAMAGES WERE REASONABLY FORESEEABLE, AND ARISING
OUT OF OR RELATING TO ANY USE OR DISTRIBUTION OF THIS DOCUMENT. THE
FOREGOING DISCLAIMER AND LIMITATION ON LIABILITY DO NOT APPLY TO,
INVALIDATE, OR LIMIT REPRESENTATIONS AND WARRANTIES MADE BY THE MEMBERS
AND THEIR RESPECTIVE AFFILIATES TO THE CORPORATION AND OTHER MEMBERS IN
CERTAIN WRITTEN POLICIES OF THE CORPORATION.</para>
</legalnotice>
<revhistory>
<revision>
<revnumber>2.1</revnumber>
<date>Jul-2011</date>
<author>
<personname>Hans Busch</personname>
</author>
<revremark>Split from Core 2.0 Change Requests 187, 190,
191</revremark>
</revision>
<revision>
<revnumber>2.1.1</revnumber>
<date>Jan-2012</date>
<author>
<personname>Hans Busch</personname>
</author>
<revremark>Change Request 535</revremark>
</revision>
<revision>
<revnumber>2.2.1</revnumber>
<date>Dec-2012</date>
<author>
<personname>Hans Busch</personname>
</author>
<revremark>Change Request 708</revremark>
</revision>
<revision>
<revnumber>2.3</revnumber>
<date>May-2013</date>
<author>
<personname>Michio Hirai</personname>
</author>
<revremark>Change Request 972</revremark>
</revision>
<revision>
<revnumber/>
<date/>
<revremark>Change Request 1843</revremark>
</revision>
</revhistory>
</info>
<chapter>
<title>Contents</title>
<bridgehead renderas="sect1">Scope</bridgehead>
<para>This document defines the web service interface for configuration of
the display of a Video rendering device with optional Audio support.
Additionally the associated events are defined.</para>
<para>Web service usage is outside of the scope of this document. Please
refer to the ONVIF core specification.</para>
</chapter>
<chapter>
<title>Normative references</title>
<para>ONVIF Core Specification</para>
<para role="reference"><<link
xlink:href="http://www.onvif.org/specs/core/ONVIF-Core-Specification.pdf"/>></para>
<para>ONVIF Receiver Service Specification</para>
<para role="reference"><<link
xlink:href="http://www.onvif.org/specs/srv/rcv/ONVIF-Receiver-Service-Spec.pdf"/>></para>
<para>ONVIF DeviceIO Service Specification</para>
<para role="reference"><<link
xlink:href="http://www.onvif.org/specs/srv/io/ONVIF-DeviceIo-Service-Spec.pdf"/>></para>
</chapter>
<chapter>
<title>Terms and Definitions</title>
<section>
<title>Definitions</title>
<informaltable>
<tgroup cols="2">
<colspec colname="c1" colwidth="24*"/>
<colspec colname="c2" colwidth="76*"/>
<tbody valign="top">
<row>
<entry align="left"><para> <emphasis
role="bold">Layout</emphasis> </para></entry>
<entry align="left"><para>Defines the arrangement of display
areas (panes) on a monitor</para></entry>
</row>
<row>
<entry align="left"><para> <emphasis role="bold">Pane</emphasis>
</para></entry>
<entry align="left"><para>Defines an area on a physical
display.</para></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</section>
<section>
<title>Abbreviations</title>
<informaltable>
<tgroup cols="2">
<colspec colname="c1" colwidth="24*"/>
<colspec colname="c2" colwidth="76*"/>
<tbody valign="top">
<row>
<entry valign="middle"><para>RTSP</para></entry>
<entry valign="middle"><para>Real Time Streaming
Protocol</para></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</section>
</chapter>
<chapter>
<title>Overview</title>
<para>The display service provides functions to enable a client to control
and configure display devices. The service introduces panes, each of which
occupies an area of the physical display. The configuration of the pane
maps audio inputs and outputs to a video output. The configuration also
references a Receiver Object which receives the data to be displayed.
Functions to retrieve and configure the configuration of a pane are
provided.</para>
<figure>
<title>Example layout with six panes and coordinate system</title>
<mediaobject>
<imageobject>
<imagedata fileref="media/Display/panelayout.svg" contentwidth="120mm" />
</imageobject>
</mediaobject>
</figure>
<para>A layout defines how these panes are visible on the display (e.g
single view or quad view). The service introduces commands to retrieve the
current layout of a display and change the layout.</para>
<para>The service also introduces commands to request the encoding and
decoding capabilities of a video output as well as the layout
options.</para>
<para>WSDL for the display service is specified in <link
xlink:href="http://www.onvif.org/ver10/display.wsdl">http://www.onvif.org/ver10/display.wsdl</link>.</para>
<table>
<title>Referenced namespaces (with prefix)</title>
<tgroup cols="2">
<colspec colname="c1" colwidth="13*"/>
<colspec colname="c2" colwidth="87*"/>
<thead>
<row>
<entry><para>Prefix</para></entry>
<entry><para>Namespace URI</para></entry>
</row>
</thead>
<tbody valign="top">
<row>
<entry><para>env</para></entry>
<entry><para>http://www.w3.org/2003/05/soap-envelope</para></entry>
</row>
<row>
<entry><para>ter</para></entry>
<entry><para>http://www.onvif.org/ver10/error</para></entry>
</row>
<row>
<entry><para>xs </para></entry>
<entry><para>http://www.w3.org/2001/XMLSchema </para></entry>
</row>
<row>
<entry><para>tt</para></entry>
<entry><para>http://www.onvif.org/ver10/schema</para></entry>
</row>
<row>
<entry><para>tls</para></entry>
<entry><para>http://www.onvif.org/ver10/display/wsdl</para></entry>
</row>
</tbody>
</tgroup>
</table>
</chapter>
<chapter>
<title>Display Service</title>
<para>A display device has a fixed number of video outputs, each of which
may be attached to a monitor. A client can request the video outputs of
the device using the DeviceIO service. Each of these outputs is configured
with a layout (e.g. single view or split screen). The layout defines a
number of video panes, each of which occupies an area of the physical
display.</para>
<para>A network video display may also have fixed number of audio inputs
and audio outputs. Each of these outputs may be associated with a pane.
Associating an audio input or output with a pane maps the audio and video
streams from a transmitter device automatically to the correct outputs.
The pane also contains a pointer to a receiver where the necessary
information to connect the display device to a transmitter is
stored.</para>
<para>The Display Service offers functions to configure the Panes and
describe and change the layout of the display device. The possible layouts
and coding capabilities of a video output can be requested.</para>
<para>A display device shall support the Display Service as defined in
[DisplayService.wsdl].</para>
<section>
<title>Panes</title>
<para>A Pane is a display area on the monitor that is attached to a
video output. A pane has a PaneConfiguration that describes which
entities are associated with the pane. The PaneConfiguration
includes:</para>
<para><emphasis role="bold">Pane Token: </emphasis>A unique identifier
in the display device.</para>
<para><emphasis role="bold">Pane Name</emphasis>: Configuration
name.</para>
<para><emphasis role="bold">AudioOutputToken</emphasis>: A pointer to
the audio output that is associated with the pane. A client can retrieve
the available audio outputs of a device using the GetAudioOutputs
command of the DeviceIO service.</para>
<para><emphasis role="bold">AudioSourceToken</emphasis>: A pointer to
the audio source that is associated with this pane. The audio connection
from a display device to a client is established using the backchannel
mechanism. A client can retrieve the available audio sources of a device
using the GetAudioSources command of the DeviceIO service.</para>
<para><emphasis role="bold">AudioEncoderConfiguration</emphasis>: The
configuration of the audio encoder including codec, bitrate and sample
rate.</para>
<para><emphasis role="bold">ReceiverToken</emphasis>: A pointer to a
receiver as defined in the ONVIF Receiver Service Specification that has
the necessary information to receive Data from a Transmitter. This
Receiver can be connected and the network video display displays the
received data on the specified outputs. A client can retrieve the
available Receivers using the GetReceivers command of the Receiver
Service.</para>
<para>A client has to configure the pane according to the connection to
be established by setting the AudioOutput and/or AudioSourceToken. If a
Token is not set, the corresponding session will not be
established.</para>
<para>Changing the PaneConfiguration or the parameters of a referenced
receiver shall not affect the RTSP connection. If a client intends to
apply the new parameters it shall restart the RTSP connection.</para>
<para>The pane layout (see <xref linkend="_Ref245539587"/>) of the video
output defines if and where (position, size) a Pane is currently
visible. The receiver should only establish an RTSP connection to
receive data if the pane is visible. Layout changes shall not affect
running streams.</para>
<section>
<title>GetPaneConfigurations</title>
<para>This command lists all currently defined Panes of a device for a specified video
output (regardless if this pane is visible at a moment). A display device shall support
the retrieval of its configured panes through this command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">The VideoOutput element specifies the Video
Output whose PaneConfigurations are requested.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="param">PaneConfiguration - unbounded
[tt:PaneConfiguration]</para>
<para role="text">Contains a list of defined Panes of the
specified VideoOutput. Each VideoOutput has at least one
PaneConfiguration.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output does not
exist</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">READ_MEDIA</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>GetPaneConfiguration</title>
<para>If the pane token is already known this command can be used to
get the pane configuration. A display device shall support the
retrieval of a specific pane configuration through this
command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">This message contains the token of the pane
whose configuration is requested. It also contains a VideoOutput
token that specifies the Video Output that contains the
requested pane.</para>
<para role="param">Pane [tt:ReferenceToken]</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="param">PaneConfiguration
[tt:PaneConfiguration]</para>
<para role="text">Contains the requested
PaneConfiguration</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoPane</para>
<para role="text">The requested pane does not exist</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output does not
exist</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">READ_MEDIA</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>SetPaneConfigurations</title>
<para>This command changes the Configuration of all existing panes in
one step. The message contains all PaneConfigurations (modified and
not modified ones) of the video output. A display device shall support
the modification of its panes configuration through this
command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">This message contains the configuration of all
panes of the specified VideoOutput. The PaneConfiguration
element contains the modified configuration.</para>
<para role="param">PaneConfiguration - unbounded
[tt:PaneConfiguration]</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="text">This is an empty message.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:invalidConfig</para>
<para role="text">The configuration is not possible to
set</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output does not
exist</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">ACTUATE</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>SetPaneConfiguration</title>
<para>This command changes the Configuration of a single pane. A
display device shall support the modification of a single pane
configuration through this command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">This message contains the token of the video
output and the new PaneConfiguration.</para>
<para role="param">PaneConfiguration
[tt:PaneConfiguration]</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="text">This is an empty message.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoPane</para>
<para role="text">The requested pane does not exist</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output does not
exist</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:InvalidConfig</para>
<para role="text">The configuration is not possible to
set</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">ACTUATE</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>CreatePaneConfiguration</title>
<para>This command creates a pane configuration. A display device that
supports dynamic creation of panes shall support the creation of a
pane configuration through this command.</para>
<para>A service implementation is free to choose any suitable token
for the PaneConfiguration and may ignore the content of the token
field.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para>This message contains the token of the video output and
the new PaneConfiguration.</para>
<para role="param">PaneConfiguration
[tt:PaneConfiguration]</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="param">PaneToken [tt:ReferenceToken]</para>
<para role="text">This message contains the token of the the new
PaneConfiguration.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:MaxNumberOfPane</para>
<para role="text">The maximum number of panes is reached</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output does not
exist</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:InvalidConfig</para>
<para role="text">The configuration is not possible to
set</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">ACTUATE</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>DeletePaneConfiguration</title>
<para>This command deletes a pane configuration. A display device that
supports dynamic deletion of panes shall support the deletion of a
pane configuration through this command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">This message contains the token of the video
output and the PaneConfiguration.</para>
<para role="param">PaneToken [tt:ReferenceToken]</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="text">This is an empty message.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:FixedPane</para>
<para role="text">It is not possible to delete this pane
configuration</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output does not
exist</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoPane</para>
<para role="text">The requested pane configuration does not
exist.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">ACTUATE</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</section>
<section xml:id="_Ref245539587">
<title>Layout</title>
<para>The Layout assigns a pane configuration to a certain area of the
display. The layout settings directly affect a specific video output.
The layout consists of a list of PaneConfigurations and their associated
display areas. If the device supports overlapping panes then the order
the panes are displayed on the monitor is defined by the order of the
PaneConfigurations in the list. The first Pane in the list is the one
that is displayed in the foreground.</para>
<para>A device may either provide a fixed number of supported layouts or
it is possible to configure the layout free.</para>
<section>
<title>GetLayout</title>
<para>This command returns the current layout of a video output. A
display device shall support the retrieval of its layout through this
command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">Contains the VideoOutputToken of the output
the display is connected to.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="param">Layout [tt:Layout]</para>
<para role="text">Contains the current layout of the
VideoOutput.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output indicated with
VideoOutput does not exist.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">READ_MEDIA</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>SetLayout</title>
<para>The SetLayout operation can be used to change the layout of a
display (e.g. change from single view to split screen view). A display
device shall support the change of layout through this command.</para>
<para>A device implementation shall be tolerant against rounding
errors when matching a layout against its fixed set of layouts by
accepting differences of at least one percent.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para role="text">Contains the VideoOutputToken of the output
the display is connected to.</para>
<para role="param">Layout [tt:Layout]</para>
<para role="text">Layout configuration to be applied.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para>This message is an empty message.</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested Video Output indicated with
VideoOutput does not exist.</para>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:InvalidLayout</para>
<para role="text">It is not possible to set the layout.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">ACTUATE</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</section>
<section>
<title>Display Options</title>
<para>The Display Options contain the supported layouts (LayoutOptions)
and the decoding and encoding capabilities (CodingCapabilities) of the
device. The GetDisplayOptions command returns both, Layout and Coding
Capabilities, of a VideoOutput.</para>
<para><emphasis role="bold">LayoutOptions</emphasis></para>
<para>The LayoutOptions describe the fixed and predefined layouts of a
device. If the device does not offer fixed layouts and allows setting
the layout free this element is empty.</para>
<para><emphasis role="bold">Coding Capabilities</emphasis></para>
<para>The network video display is able to decode audio and video
streams using suitable decoding algorithms. The network video display
supports any audio and video decoders, bitrates and resolution according
to the manufacturer‘s choice.</para>
<para>In order to ensure interoperability between the different devices,
this specification mandates the following decoder profiles:</para>
<para>The NVD shall support JPEG QVGA.</para>
<para>The NVD shall support G.711μ Law (if it supports audio)</para>
<para>These are the same codecs that are mandatory for Profile S
clients.</para>
<para>There are no parameters to configure a decoder; a decoder shall
decode all content (according to its capabilities) it receives. In case
of decoding errors the decoder should try to request a synchronization
point and try to continue decoding. It shall generate an event as
defined in section <xref linkend="_Ref287274188"/>.</para>
<para>The CodingCapabilities Element gives an indication about the
decoding and encoding capabilities of the device.</para>
<section>
<title>GetDisplayOptions</title>
<para>This command lists layout and coding capabilities of a video
output. A display device shall support the retrieval of its
DisplayOptions through this command.</para>
<variablelist role="op">
<varlistentry>
<term>request</term>
<listitem>
<para role="param">VideoOutput [tt:ReferenceToken]</para>
<para>This message contains the token of the video output for
which the information is requested.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>response</term>
<listitem>
<para role="param">LayoutOptions optional
[tt:LayoutOptions]</para>
<para>Message containing the available layouts as well as
codings for the VideoOutput.</para>
<para role="param">CodingCapabilities
[tt:CodingCapabilities]</para>
</listitem>
</varlistentry>
<varlistentry>
<term role="param">faults</term>
<listitem>
<para role="param">env:Sender - ter:InvalidArgVal -
ter:NoVideoOutput</para>
<para role="text">The requested VideoOutputToken does not
exist</para>
</listitem>
</varlistentry>
<varlistentry>
<term>access class</term>
<listitem>
<para role="access">READ_MEDIA</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</section>
<section>
<title>Events</title>
<para>The display service shall dispatch events through the event
service.</para>
<section xml:id="_Ref287274188">
<title>Decoding error event</title>
<para>The device shall be capable of generating the following event
whenever it receives a bitstream that it is not able to decode.</para>
<para>There are several reasons why a decoder is not able to decode
the bitstream. The following error codes are defined and shall be used
by the device to inform the client about decoder errors:</para>
<orderedlist>
<listitem>
<para>“unsupported codec or unsupported codec profile” – The
device is not able to decode the bitstream, because the codec or
the profile is not supported by the device. The client should the
try to reconfigure the transmitter according to the
CodingCapabilities of the device.</para>
</listitem>
<listitem>
<para>“packet error” – there are missing or unexpected packets in
the bitstream.</para>
</listitem>
</orderedlist>