1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Media device model</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API"><link rel="up" href="media_controller.html" title="Chapter&#160;18.&#160;Media Controller"><link rel="prev" href="media_controller.html" title="Chapter&#160;18.&#160;Media Controller"><link rel="next" href="media-user-func.html" title="Appendix&#160;L.&#160;Function Reference"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Media device model</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="media_controller.html">Prev</a>&#160;</td><th width="60%" align="center">Chapter&#160;18.&#160;Media Controller</th><td width="20%" align="right">&#160;<a accesskey="n" href="media-user-func.html">Next</a></td></tr></table><hr></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="media-controller-model"></a>Media device model</h2></div></div></div><p>Discovering a device internal topology, and configuring it at runtime,
2    is one of the goals of the media controller API. To achieve this, hardware
3    devices are modelled as an oriented graph of building blocks called entities
4    connected through pads.</p><p>An entity is a basic media hardware or software building block. It can
5    correspond to a large variety of logical blocks such as physical hardware
6    devices (CMOS sensor for instance), logical hardware devices (a building
7    block in a System-on-Chip image processing pipeline), DMA channels or
8    physical connectors.</p><p>A pad is a connection endpoint through which an entity can interact
9    with other entities. Data (not restricted to video) produced by an entity
10    flows from the entity's output to one or more entity inputs. Pads should not
11    be confused with physical pins at chip boundaries.</p><p>A link is a point-to-point oriented connection between two pads,
12    either on the same entity or on different entities. Data flows from a source
13    pad to a sink pad.</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="media_controller.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="media_controller.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="media-user-func.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter&#160;18.&#160;Media Controller&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;Appendix&#160;L.&#160;Function Reference</td></tr></table></div></body></html>
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