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31 lines
1.2 KiB
Markdown
31 lines
1.2 KiB
Markdown
---
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title: Writing a Manager
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...
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# Writing a Manager
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Managers are elements that add a function or unify the function of
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another (series of) element(s). Managers are generally a `GstBin` with
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one or more ghostpads. Inside them is/are the actual element(s) that
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matters. There is several cases where this is useful. For example:
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- To add support for private events with custom event handling to
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another element.
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- To add support for custom pad `_query ()` or `_convert ()` handling
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to another element.
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- To add custom data handling before or after another element's data
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handler function (generally its `_chain ()` function).
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- To embed an element, or a series of elements, into something that
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looks and works like a simple element to the outside world. This is
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particular handy for implementing sources and sink elements with
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multiple pads.
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Making a manager is about as simple as it gets. You can derive from a
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`GstBin`, and in most cases, you can embed the required elements in the
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`_init ()` already, including setup of ghostpads. If you need any custom
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data handlers, you can connect signals or embed a second element which
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you control.
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