diff --git a/docs/random/wtay/autoplug3 b/docs/random/wtay/autoplug3 new file mode 100644 index 0000000000..4cf16a4ef5 --- /dev/null +++ b/docs/random/wtay/autoplug3 @@ -0,0 +1,38 @@ + +The autoplugger is a custom bin with a set of custom add/remove methods. +The point is to virtually add a set of plugins that should take part in +the autoplugging (like the src, sink elements). The autoplugger should +try hard to included these plugins in the final pipeline. + +The autoplugger has to be a bin because else we cannot put it into the +paused state when dynamically connecting elements. + +We cannot include the intermediate elements or sink/src elements to the bin +right away because else they will be scheduled by the scheduler. + +The bin will use the elementfactory klass field to get a basic idea about +the plugin: + + - the 'Source' keyword is used to detect source elements + - the 'Sink' keyword is used to detect the sink elements or targets + of the autoplugging. + - other elements are considered intermediate elements and will be + inserted when possible. + + +algorithm: + +- Autoplugging starts from a source element, it will be added to the real bin. +- for all unconnected pads: + - if pad has NULL padtemplate caps add typefind + autoplugcache to the pad +- if unconnected pad has fixed caps, find element in repository that can + connect. + - first check elements added to the bin + - test elements ordered by rank + - favour 'Demux' type elements close to sources, 'Decoder' elements after + that and 'Filter' elements close to sinks. +- link dummy element with pads with non-fixed caps. The dummy element getcaps + function will use the repository to return a list of compatible caps, so that + the element can choose freely. The dummy element is replaced with a real + element when caps become fixed. +- all new_pad signals and caps notifications trigger the above actions.