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<concept id="GUID-36C3A2FD-F4F9-5B8C-91B7-40C29B3D2224" xml:lang="en"><title> Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>This section provides an overview of the Camera Framework. </p>

<section id="GUID-E7594254-F6E9-4462-B34B-0955939BAECC"><title>Purpose</title> <p>The ECam component supplies a header file

(<filepath>.h</filepath>) and library definition files (<filepath>.def</filepath>).

These specify the API and binary interfaces that device creators can implement.

They provide an interface for cross-platform, compatible camera clients to

access the camera on any given device. The Camera Framework supports any concrete

ECam implementation only as a ECom plug-in. The ROM plug-in with the highest

version number is selected at instantiation phase. The Symbian version of

ECam is a stub for easy replacement by an alternate implementation. </p> </section>

<section id="GUID-D5088EB7-2014-4D34-84DD-DE88188F9F31"><title>Required background</title> <p>ECam is a component of the

Multimedia subsystem. </p> </section>

<section id="GUID-F6CD9CCA-4508-42BE-A3DE-5F0A74CD1D20"><title>Architectural relationships</title> <p>Clients have specific

priorities and may pre-empt others in their interactions with the camera.

When a camera client needs to share the camera with another client, it creates

a handle to the camera and passes this handle to the component. Clients that

share with each other are called collaborative clients. </p> <p>Platform security

requires that applications have the <codeph>UserEnvironment</codeph> capability

to create a Camera object. Clients with the <codeph>MultimediaDD</codeph> capability

are given a higher priority. </p> <p> <b>Note</b>: The process by which a

client passes a handle to another client is beyond the scope of this Camera

Framework guide. </p> <p>Application developers and device creators implement

the ECam API for the camera hardware on their phone. All cameras are ECom

plug-ins sub-classed from the <xref href="GUID-A738B809-754B-3090-9209-0880687F173C.dita"><apiname>CCameraPlugin</apiname></xref> class. </p> </section>

<section id="GUID-C8B479FA-6806-43D0-84D2-1F1627CBBE07"><title>API summary</title> <p>The Camera Framework includes the following

APIs. </p> <p><b>ECam APIs </b> </p> <ul>

<li id="GUID-A35FED19-B5AE-5134-8EB6-A00F0B7A53C9"><p>Camera </p> <p>This

provides functionality to control a digital camera and to request and receive

specific image data from it. </p> <p>See also <xref href="GUID-80EC80E2-E197-50F7-B1FD-720A00AC3B4D.dita#GUID-80EC80E2-E197-50F7-B1FD-720A00AC3B4D/GUID-1AC509C3-E1D9-5DB4-9C09-90E0DCE576CB">Key

Onboard ECam API Classes</xref>  </p> </li>

<li id="GUID-5327CE4E-6BA6-5602-8D17-0ADFDFBEA5DA"><p>Advanced Settings </p> <p>This

provides domain specific getters and setters for well known camera hardware

settings. This is used to query the camera for the list of supported and currently

active hardware settings. For a specific setting, clients can query the camera

for the list of supported values. </p> </li>

<li id="GUID-646EBF1D-FF4F-5C2E-8D87-DD1CE9072A00"><p>Camera Viewfinder </p> <p>This

provides the support for both direct and client viewfinder. It also provides

information regarding the current state of that direct viewfinder. The different

possible states are active, paused and inactive. </p> <p>See also <xref href="GUID-367ADFD7-A0F5-59D3-BF83-913CB8126B9D.dita#GUID-367ADFD7-A0F5-59D3-BF83-913CB8126B9D/GUID-FD016694-527F-5009-81FC-B5D8AD1A3A05">Key Viewfinder Classes</xref>  </p> <p> <b>Note</b>: The direct viewfinder

is applicable only for viewfinders that use Ccamera viewfinder methods. </p> </li>

<li id="GUID-F63B7492-08A2-5129-B89B-06CCC459EF04"><p>Camera Histogram </p> <p>This

gets the histogram data in a specified format for an image (for example, luminance

based histogram, average colour value histogram and so on). </p> </li>

<li id="GUID-EC209FE8-B8B2-59E0-80DA-13801366F03B"><p>Camera Overlay </p> <p>This

overlays an image onto the viewfinder, snapshots, still images and video.

A client can create multiple overlays, each one with different properties. </p> </li>

<li id="GUID-05130CA9-EFCD-59EA-871E-923E89122234"><p>Camera plug-in Support </p> <p>All

cameras are ECom plug-ins sub-classed from <xref href="GUID-A738B809-754B-3090-9209-0880687F173C.dita"><apiname>CCameraPlugin</apiname></xref> class

and register support for the interface <xref href="GUID-ED2C5C88-0EBF-3793-A451-91C5F9030467.dita"><apiname>KUidOnboardCameraPlugin</apiname></xref> in

their resource file. Symbian introduced plug-in support for ECam from v9.1

onwards. Before that, device creators were supposed to re-implement ECam,

which was effectively reference code. </p> </li>

<li id="GUID-EB2D5447-2D4F-5413-B0A8-17AA86982B0A"><p>Camera Snap Shot </p> <p>Clients

can use snapshots to show captured images on the display almost instantly

(while in the background the image may be processed by using some compression

algorithm before storing the data). The client can specify the properties

of the snapshot, such as size, background colour and position to be used if

the snapshot has been scaled and so on. Snapshot object can be created specifically

for still images and video APIs. </p> </li>

</ul> </section>

<section id="GUID-1DA7183B-01F5-468B-8F59-1A817DDA0DC4"><title>Typical uses</title> <p><b>Camera Component Users </b> </p> <ul>

<li id="GUID-D2AD15FD-E2DE-5137-BE77-650CCD5DE9A6"><p>Camera plug-ins </p> </li>

<li id="GUID-77873CF0-7319-59D6-9EA6-0B922E7E3A3F"><p>Multimedia Framework

plug-ins </p> </li>

</ul> <p><b>Camera

Component tasks</b> </p> <p>The camera component is used for the following: </p> <ul>

<li id="GUID-4A7DF7A6-4E35-53DB-9F56-A5D0E2685FBA"><p>Onboard Camera </p> </li>

<li id="GUID-DF4050DA-AEC1-5C91-9466-FC685B21EBCC"><p>Camera plug-in Support </p> </li>

<li id="GUID-4D9B817A-666C-5A15-B285-5B292C209C5A"><p>Advanced Settings </p> </li>

<li id="GUID-E187EEC6-C048-5AB0-944B-BCBFC2CFD986"><p>Camera plug-in </p> </li>

<li id="GUID-DD4EB3CF-EEAC-5208-989D-1B9A94320CCF"><p>Histogram </p> </li>

<li id="GUID-4F24A091-31CE-592E-9447-A5424FA814C5"><p>Overlay </p> </li>

<li id="GUID-7F01D2E4-49E3-53C9-AE0A-D40BB6C8304E"><p>Snapshot </p> </li>

<li id="GUID-EBD1D801-E9FE-561D-A656-AE4095B878E4"><p>Viewfinder </p> </li>

</ul> <p><b> Onboard

Camera </b> </p> <p>The Onboard Camera provides functionality to control a

digital camera and to request and receive specific image data from it. </p> <p><b> Advanced Settings </b> </p> <p>The Advanced Settings gets or sets individual

setting value as well as retrieve their current ranges. </p> <p><b> Camera plug-in</b> </p> <p>This API, an ECom plug-in, is introduced as

an alternative to static linking. This allows the partners to replace the

camera implementation more easily. </p> <p><b> Histogram</b> </p> <p>The Histogram provides the functionality needed to work with histogram

data in a specified format for an image. </p> <p><b> Overlay</b> </p> <p>The Overlay is used to overlay an image onto the

viewfinder, snapshots, still images and video. </p> <p><b> Snapshot</b> </p> <p>The Snapshot allows the client to request snapshot

data in a specified image format for both still images and video. </p> <p><b> Viewfinder</b> </p> <p>The Viewfinder enables to pause and resume the

direct viewfinder which is currently active and has been started using Ccamera

methods. </p> </section>

<section id="GUID-47470D3B-FFA2-495C-BBCC-2267EFA839A7"><title>See also</title> <p><xref href="GUID-80EC80E2-E197-50F7-B1FD-720A00AC3B4D.dita">Onboard

Camera Overview</xref>  </p> <p><xref href="GUID-F25862A3-51E5-581A-9CC9-964791781E69.dita">Camera

Plug-in Support Overview</xref>  </p> <p><xref href="GUID-176913BA-3877-58E2-9E12-3606EE697813.dita">Advanced

Camera Settings Overview</xref>  </p> <p><xref href="GUID-3074D4E5-25EA-5DA0-877D-6E3086DCBDB5.dita">Histogram

Overview</xref>  </p> <p><xref href="GUID-AB5BD17E-F482-54A1-AE6F-4AEC178B2E0E.dita">Overlay

API Overview</xref>  </p> <p><xref href="GUID-0B24B36D-F4C5-508A-A65B-18E4E4C45C37.dita">Snapshot

API Overview</xref>  </p> <p><xref href="GUID-367ADFD7-A0F5-59D3-BF83-913CB8126B9D.dita">Viewfinder

API Overview</xref>  </p> </section>

</conbody></concept>