docs: add communication overview to docs

Add a section to the basics that show buffers, events, messages and queries
together and describe the basics.
This commit is contained in:
Stefan Kost 2010-03-31 09:56:50 +03:00
parent 05fd9d0aba
commit 5799aa28e3
3 changed files with 835 additions and 109 deletions

Binary file not shown.

After

Width:  |  Height:  |  Size: 29 KiB

File diff suppressed because it is too large Load diff

Before

Width:  |  Height:  |  Size: 622 KiB

After

Width:  |  Height:  |  Size: 660 KiB

View file

@ -97,4 +97,54 @@
</sect1>
<sect1 id="section-intro-basics-communication">
<title>Communication</title>
<para>
&GStreamer; provides several mechanisms for communication and data exchange
between the <emphasis>application</emphasis> and the <emphasis>pipeline</emphasis>.
</para>
<itemizedlist>
<listitem>
<para>
<emphasis>buffers</emphasis>: are objects for passing streaming data
between elements in the pipeline. Buffers always travel from sources
to sinks (downstream).
</para>
</listitem>
<listitem>
<para>
<emphasis>events</emphasis>: are objects send between elements or from
the application to elements. Events can travel upstream and downstream.
Downstream events can be synchronised to the data flow.
</para>
</listitem>
<listitem>
<para>
<emphasis>messages</emphasis>: are object send from elements over the
bus to the application. Messages can be received synchronously, but
then from the streaming thread context of the sender or asynchronously
marshalled to the main thread of the application.
</para>
</listitem>
<listitem>
<para>
<emphasis>queries</emphasis>: allow application to request information
from the pipeline. Queries are answered synchronously.
</para>
</listitem>
</itemizedlist>
<figure float="1" id="section-communication-img">
<title>&GStreamer; pipeline with different communication flows</title>
<mediaobject>
<imageobject>
<imagedata scale="75" fileref="images/communication.&image;" format="&IMAGE;" />
</imageobject>
</mediaobject>
</figure>
</sect1>
</chapter>