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Original commit message from CVS: * docs/design/draft-push-pull.txt: * docs/design/part-MT-refcounting.txt: * docs/design/part-TODO.txt: * docs/design/part-caps.txt: * docs/design/part-events.txt: * docs/design/part-gstbus.txt: * docs/design/part-gstpipeline.txt: * docs/design/part-messages.txt: * docs/design/part-push-pull.txt: * docs/design/part-query.txt: Some more docs.
29 lines
1.3 KiB
Text
29 lines
1.3 KiB
Text
GstBus
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------
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The GstBus is an object responsible for delivering GstMessages in
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a first-in first-out way from the streaming threads to the application.
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Since the application typically only wants to deal with delivery of these
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messages from one thread, the GstBus will marshall the messages between
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different threads. This is important since the actual streaming of media
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is done in another thread than the application.
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The GstBus provides support for GSource based notifications. This makes it
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possible to handle the delivery in the glib mainloop.
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A message is posted on the bus with the gst_bus_post() method. With the
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gst_bus_peek() and _pop() methods one can look at or retrieve a previously
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posted message.
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The bus can be polled with the gst_bus_poll() method. This methods blocks
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up to the specified timeout value until one of the specified messages types
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is posted on the bus. The application can then _pop() the messages from the
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bus to handle them.
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It is also possible to get messages from the bus without any thread
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marshalling with the gst_bus_set_sync_handler() method. This makes it
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possible to react to a message in the same thread that posted the
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message on the bus. This should only be used if the application is able
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to deal with messages from different threads.
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