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abe422b141
Original commit message from CVS: reorganizing manual so that concepts are explained before code is shown. needs some proofreading, will get to it.
80 lines
2 KiB
XML
80 lines
2 KiB
XML
<chapter id="cha-links-api">
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<title>Linking elements</title>
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<sect1 id="sec-link-basic">
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<title>Making simple links</title>
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<para>
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You can link two pads with:
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</para>
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<programlisting>
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GstPad *srcpad, *sinkpad;
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srcpad = gst_element_get_pad (element1, "src");
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sinpad = gst_element_get_pad (element2, "sink");
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// link them
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gst_pad_link (srcpad, sinkpad);
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....
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// and unlink them
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gst_pad_unlink (srcpad, sinkpad);
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</programlisting>
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<para>
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A convenient shortcut for the above code is done with the gst_element_link_pads ()
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function:
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</para>
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<programlisting>
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// link them
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gst_element_link_pads (element1, "src", element2, "sink");
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....
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// and unlink them
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gst_element_unlink_pads (element1, "src", element2, "sink");
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</programlisting>
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<para>
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An even more convenient shortcut for single-source, single-sink elements is the
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gst_element_link () function:
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</para>
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<programlisting>
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// link them
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gst_element_link (element1, element2);
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....
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// and unlink them
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gst_element_unlink (element1, element2);
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</programlisting>
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<para>
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If you have more than one element to link, the gst_element_link_many () function takes
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a NULL-terminated list of elements:
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</para>
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<programlisting>
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// link them
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gst_element_link_many (element1, element2, element3, element4, NULL);
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....
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// and unlink them
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gst_element_unlink_many (element1, element2, element3, element4, NULL);
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</programlisting>
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<para>
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You can query if a pad is linked with GST_PAD_IS_LINKED (pad).
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</para>
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<para>
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To query for the <classname>GstPad</classname> a pad is linked to, use
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gst_pad_get_peer (pad).
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</para>
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</sect1>
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<sect1 id="sec-link-filtered">
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<title>Making filtered links</title>
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<para>
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You can also force a specific media type on the link by using gst_pad_link_filtered ()
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and gst_element_link_filtered () with capabilities.
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See <xref linkend="sec-caps"/> for
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an explanation of capabilities.
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</para>
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</sect1>
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</chapter>
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