GStreamer Application Development Manual (0.8.9.2) | ||
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By linking a source element with zero or more filter-like elements and finally a sink element, you set up a media pipeline. Data will flow through the elements. This is the basic concept of media handling in GStreamer.
By linking these three elements, we have created a very simple chain of elements. The effect of this will be that the output of the source element ("element1") will be used as input for the filter-like element ("element2"). The filter-like element will do something with the data and send the result to the final sink element ("element3").
Imagine the above graph as a simple Ogg/Vorbis audio decoder. The source is a disk source which reads the file from disc. The second element is a Ogg/Vorbis audio decoder. The sink element is your soundcard, playing back the decoded audio data. We will use this simple graph to construct an Ogg/Vorbis player later in this manual.
In code, the above graph is written like this:
#include <gst/gst.h> int main (int argc, char *argv[]) { GstElement *source, *filter, *sink; /* init */ gst_init (&argc, &argv); /* create elements */ source = gst_element_factory_make ("fakesrc", "source"); filter = gst_element_factory_make ("identity", "filter"); sink = gst_element_factory_make ("fakesink", "sink"); /* link */ gst_element_link_many (source, filter, sink, NULL); [..] } |
For more specific behaviour, there are also the functions gst_element_link () and gst_element_link_pads (). You can also obtain references to individual pads and link those using various gst_pad_link_* () functions. See the API references for more details.
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