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Added some chain/group
Original commit message from CVS: Added some chain/group Added more docs
This commit is contained in:
Wim Taymans
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5b5274daf2
commit
a82fd94231
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@ -93,6 +93,8 @@ DECOUPLED
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* never loop-based
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* always acts like a chain-based sink for upstream elements
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* always acts like a get-based src for downstream elements
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* are not added to a group, but marked as an entry point in
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case it acts as a src element
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Connection types
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@ -136,9 +138,16 @@ A)
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- get based source
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- chain based sink
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* src at start of chain and entry point
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* one group
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* src at start of group and entry point
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* _get from src, push to sink
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(-group1---------------)
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! !
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! *fakesrc -> fakesink !
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(----------------------)
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B)
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src -> sink
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@ -151,8 +160,14 @@ B)
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- loop based source/filter
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- chain based sink/filter/decoupled
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* src/filter at start of chain and entry point
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* loop on src, pushhandler set to chain function
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* one group
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* src/filter at start of group and entry point
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* loop on src, chainhandler set to chain function
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(-group1----------------)
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! !
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! %*fakesrc -> fakesink !
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(-----------------------)
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C)
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@ -165,9 +180,14 @@ C)
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- get based source/decoupled
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- loop based sink/filter
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* one group
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* loop based element is entry point
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* loop on sink/filter, pullhandler set to _getfunction
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* loop on sink/filter, gethandler set to getfunction
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(-group1----------------)
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! !
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! fakesrc -> %*fakesink !
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(-----------------------)
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D)
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@ -178,9 +198,15 @@ D)
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- chain based filter
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- chain based filter/sink/decoupled
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* one group is created to hold the two elements
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* no entry point
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* pushhandler set to peer chainfunction
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* chainhandler set to peer chainfunction
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(-group1----------------)
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! !
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! identity -> identity !
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(-----------------------)
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E)
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filter -> filter
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@ -189,8 +215,17 @@ E)
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- chain based filter
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- loop based filter/sink
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* entry point in chain of filter
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* pushhandler set to loop wrapper
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* two groups
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* group is created for src element if needed
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* chainhandler of loop based element set to loop wrapper, control is
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handed to the peer group
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* gethandler of loop based element set to get wrapper
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(-group1---) (-group2------)
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! ! ! !
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! identity ---> %*identity !
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(----------) (-------------)
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F)
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@ -202,25 +237,41 @@ F)
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- loop based filter/src
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- loop based filter/sink
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* entry point in chain of filter/src
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* pushhandler set to loop wrapper
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* two groups
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* two entry points
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* chainhandler set to loop wrapper
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* gethandler set to get wrapper
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(-group1-----) (-group2------)
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! ! ! !
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! %*identity ---> %*identity !
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(------------) (-------------)
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Grouping
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--------
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* a group has at most one loop based element
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* elements in a group are sorted, src elements first
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* elements in a group are sorted, src elements first (not mandatory)
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* a group has one cothread
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* a group is created immediatly for loop based elements, all other elements
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are added to a group when a pad connection is made
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* get-based plugins are put in the same group as a peer loop based element
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* chain based elements are put in the same group
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* chain based elements are put in the same group as sink peer elements
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* entry point in the group is:
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- leftmost loopbased element
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- first src element if no loopbased elements exist in the group
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- loopbased element
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- first src element if no loopbased element exists in the group
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Result: you end up with a group of connected elements with either:
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- a loop based plugin as the entry point
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- a get based plugin as the entry point
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Scheduling the group is a matter of starting the cothread and calling
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the loop function or doing a _get/_push on a srcpad.
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examples:
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---------
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other examples of groups:
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-------------------------
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% = loop based
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* = entry point of group
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@ -289,7 +340,19 @@ examples:
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(------------------------------) (-----------------------------)
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Chaining
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--------
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* groups that are connected end up in the same chain
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* a group always belongs to a chain
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* updating the chain is only needed when two groups are
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connected with a connection of type E/F. for other
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connection types, the group itself is updated.
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* a chain is scheduled by scheduling a random group in the chain.
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Wrapper functions
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-----------------
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