gst.context
Module for [Context] class
Types 1
#GstContext is a container object used to store contexts like a device context, a display server connection and similar concepts that should be shared between multiple elements.
Applications can set a context on a complete pipeline by using [gst.element.Element.setContext], which will then be propagated to all child elements. Elements can handle these in #GstElementClass::set_context and merge them with the context information they already have.
When an element needs a context it will do the following actions in this order until one step succeeds:
- Check if the element already has a context
- Query downstream with [gst.types.QueryType.Context] for the context
- Query upstream with [gst.types.QueryType.Context] for the context
- Post a [gst.types.MessageType.NeedContext] message on the bus with the required
context types and afterwards check if a usable context was set now
- Create a context by itself and post a [gst.types.MessageType.HaveContext] message
on the bus.
Bins will catch [gst.types.MessageType.NeedContext] messages and will set any previously known context on the element that asks for it if possible. Otherwise the application should provide one if it can.
#GstContext can be persistent. A persistent #GstContext is kept in elements when they reach [gst.types.State.Null], non-persistent ones will be removed. Also, a non-persistent context won't override a previous persistent context set to an element.
Context self()Returns `this`, for use in `with` statements.string getContextType()Gets the type of context. Returns: The type of the context.gst.structure.Structure getStructure()Accesses the structure of the context. Returns: The structure of the context. The structure is still owned by the context, which means that you should not modify it, free it and that the pointer be...bool hasContextType(string contextType)Checks if context has context_type.bool isPersistent()Checks if context is persistent. Returns: true if the context is persistent.gst.structure.Structure writableStructure()Gets a writable version of the structure. Returns: The structure of the context. The structure is still owned by the context, which means that you should not free it and that the pointer becomes in...