Writing a Manager

Managers are elements that add a function or unify the function of another (series of) element(s). Managers are generally a GstBin with one or more ghostpads. Inside them is/are the actual element(s) that matters. There is several cases where this is useful. For example:

• To add support for private events with custom event handling to another element.

• To add support for custom pad _query () or _convert () handling to another element.

• To add custom data handling before or after another element's data handler function (generally its _chain () function).

• To embed an element, or a series of elements, into something that looks and works like a simple element to the outside world. This is particular handy for implementing sources and sink elements with multiple pads.

Making a manager is about as simple as it gets. You can derive from a GstBin, and in most cases, you can embed the required elements in the _init () already, including setup of ghostpads. If you need any custom data handlers, you can connect signals or embed a second element which you control.