Added some chain/group

Original commit message from CVS:
Added some chain/group
Added more docs
This commit is contained in:
Wim Taymans 2002-09-10 20:28:25 +00:00
parent 5b5274daf2
commit a82fd94231

View file

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