Added case6: a multithreaded audio mixer setup.

Original commit message from CVS:
Added case6: a multithreaded audio mixer setup.

diff --git a/docs/random/wtay/eos3 b/docs/random/wtay/eos3
index 40d92fdaaa968421c363577a1a2053c6e97dbe7f..abe7afda411ed441e864f40b2d77f768824c1741 100644 (file)
--- a/docs/random/wtay/eos3
+++ b/docs/random/wtay/eos3
@@ -198,29 +198,56 @@ case 5)
   and audio is playing again...
 
 
+case 6) 
+
+(-------------------------------------------------------------------------------------)
+! bin                                                                                 !
+!                                                                   (---------------) !
+! (---------------------------------------------)                   !audiosink      ! !
+! ! thread1                                     !                   !               ! !
+! ! (--------)       (----------)      (-----)  !   (--------)      !               ! !
+! ! !disksrc1!       ! effect   !      !queue!  !   ! mixer  !      !               ! !
+! ! !       src -- sink        src -- sink  src -- sink     src -- sink             ! !
+! ! (--------)       (----------)      (-----)  !   !        !      !               ! !
+! (---------------------------------------------)   !        !      !               ! !
+!                                                   !        !      (---------------) !
+! (---------------------------------------------)   !        !                        !
+! ! thread2                                     !   !        !                        !
+! ! (--------)       (----------)      (-----)  !   !        !                        !
+! ! !disksrc2!       ! effect   !      !queue!  !   !        !                        !
+! ! !       src -- sink        src -- sink  src -- sink      !                        !
+! ! (--------)       (----------)      (-----)  !   (--------)                        !
+! (---------------------------------------------)                                     !
+(-------------------------------------------------------------------------------------)
 
+  This is a simple audio mixer (mp3audio mixer).
+  We assume disksrc1 is going to be in EOS while disksrc2 is still in !EOS
 
+.scheduling.
 
+  Scheduling is a bit tricky here: we have two threads with each one chain ds1-e-q and
+  ds2-e-q. the mixer element is loop based and forms a third chain, mixer-audiosink
 
+.eos.
 
+  disksrc1 has passed the last buffer in the _get function. with its next 
+  call to _get, it will return a NULL buffer and set the src pad to EOS.
 
+  the EOS call travels up till the queue element because it has overridden
+  the handler. The first chain is disabled from the scheduler. thread1 fires EOS
+  because it does not have any chains to schedule.
 
+  the mixer element pulls buffers from queue1 until queue1 is empty. At that time,
+  queue1 sets the pad to EOS, mixer now knows that it does not have to request
+  another buffer from that pad again.
 
+  disksrc2 finally sets its pad to EOS, rendering chain2 unscheduled which makes
+  the thread2 fire an EOS.
 
-
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+  the mixer element pulls buffers from queue2 until queue2 is empty. At that time,
+  queue2 sets the pad to EOS, mixer now knows that it does not have to request
+  another buffer from that pad again. all pads for the mixer are in EOS now so
+  it sets the src pad to EOS. the last chain now also becomes unscheduled and
+  the bin fires EOS.