mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-27 04:01:08 +00:00
256 lines
11 KiB
Text
256 lines
11 KiB
Text
OUTDATED
|
|
--------
|
|
|
|
|
|
case 1)
|
|
|
|
(--------------------------------------------------)
|
|
! bin !
|
|
! (--------) (--------) (--------) !
|
|
! ! fakesrc! !identity! !fakesink! !
|
|
! ! src ----- sink src ---- sink ! !
|
|
! (--------) (--------) (--------) !
|
|
(--------------------------------------------------)
|
|
|
|
.scheduling.
|
|
|
|
case1 has just one scheduled entity (chain) no problem here.
|
|
|
|
.eos.
|
|
|
|
fakesrc detects the end of stream. It just returned the last buffer.
|
|
The next _pull will cause the srcpad to trigger gst_pad_set_eos ().
|
|
After that it will return a NULL buffer.
|
|
|
|
gst_pad_set_eos() will notify the parent about the plugins attempt to
|
|
signal eos. the parent disables scheduling for the chain containing
|
|
fakesrc.
|
|
|
|
no more chains are being scheduled so the bin fires EOS.
|
|
|
|
|
|
case 2)
|
|
|
|
|
|
(-----------------------------------------------------------------------)
|
|
! bin !
|
|
! (---------------) !
|
|
! !thread ! !
|
|
! (--------) (--------) (--------) ! (--------)! !
|
|
! ! fakesrc! !identity! ! queue ! ! !fakesink!! !
|
|
! ! src ----- sink src ---- sink src ---- sink !! !
|
|
! (--------) (--------) (--------) ! (--------)! !
|
|
! (---------------) !
|
|
(-----------------------------------------------------------------------)
|
|
|
|
.scheduling.
|
|
|
|
case2 has two scheduled entities: fsr-i-q, q-fsk.
|
|
The first one is scheduled by the bin, the second one by the thread.
|
|
|
|
.eos.
|
|
|
|
fakesrc detects the end of stream. It just returned the last buffer.
|
|
The next _pull will cause the srcpad to trigger gst_pad_set_eos ().
|
|
After that it will return a NULL buffer.
|
|
|
|
gst_pad_set_eos() will notify the parent about the plugins attempt to
|
|
signal eos. the parent will take chain1 out if its scheduled chains.
|
|
|
|
the bin does not fire EOS yet because the thread has not yet signaled
|
|
EOS.
|
|
|
|
after the queue has sent out the last buffer, its calls eos on its
|
|
src pad. the chain with the queue is removed from the threads scheduled
|
|
chains. there are no more chains to schedule, the thread fires EOS.
|
|
|
|
The bin now has no more scheduled chains and no more pending subbins,
|
|
it fires EOS.
|
|
|
|
|
|
case 3)
|
|
|
|
(-----------------------------------------------------------------------)
|
|
! bin !
|
|
! (---------------) !
|
|
! !thread ! !
|
|
! (--------) (--------) (--------) ! (--------)! !
|
|
! ! fakesrc! ! tee ! ! queue1 ! ! !fakesink!! !
|
|
! ! src ----- sink src ---- sink src ---- sink !! !
|
|
! (--------) ! ! (--------) ! (--------)! !
|
|
! ! ! (---------------) !
|
|
! ! ! !
|
|
! ! ! (---------------) !
|
|
! ! ! !thread ! !
|
|
! ! ! (--------) ! (--------)! !
|
|
! ! ! ! queue2 ! ! !fakesink!! !
|
|
! ! src ---- sink src ---- sink !! !
|
|
! ! ! (--------) ! (--------)! !
|
|
! (--------) (---------------) !
|
|
(-----------------------------------------------------------------------)
|
|
|
|
.scheduling.
|
|
|
|
case3 has tree scheduled entities: fsr-t(-q1,-q2), q1-fsk. q2-fsk
|
|
the first one is managed by the bin, the second two are managed by the
|
|
threads.
|
|
|
|
.eos.
|
|
|
|
fakesrc detects the end of stream. It just returned the last buffer.
|
|
The next _pull will cause the srcpad to trigger gst_pad_set_eos ().
|
|
After that it will return a NULL buffer.
|
|
|
|
chain1 is taken out of the scheduling algorithm of the bin.
|
|
|
|
after a while, the threads finish their scheduling and fire EOS too.
|
|
|
|
The bin now has no more scheduled chains and no more pending subbins,
|
|
it fires EOS.
|
|
|
|
|
|
case 4)
|
|
|
|
(-----------------------------------------------------------------------)
|
|
! bin !
|
|
! (---------------) !
|
|
! !thread ! !
|
|
! (--------) (----------) (--------) ! (--------)! !
|
|
! ! fakesrc! !mpeg1parse! ! queue1 ! ! !fakesink!! !
|
|
! ! src -- sink src ---- sink src ---- sink !! !
|
|
! (--------) ! ! (--------) ! (--------)! !
|
|
! ! ! (---------------) !
|
|
! ! ! !
|
|
! ! ! (---------------) !
|
|
! ! ! !thread ! !
|
|
! ! ! (--------) ! (--------)! !
|
|
! ! ! ! queue2 ! ! !fakesink!! !
|
|
! ! src ---- sink src ---- sink !! !
|
|
! ! ! (--------) ! (--------)! !
|
|
! (----------) (---------------) !
|
|
(-----------------------------------------------------------------------)
|
|
|
|
this case differs from case3 in that one of the queues can be empty
|
|
while the other isn't. we assume queue1 is empty while queue2 isn't yet.
|
|
|
|
.scheduling.
|
|
|
|
case3 has tree scheduled entities: fsr-t(-q1,-q2), q1-fsk. q2-fsk
|
|
the first one is managed by the bin, the second two are managed by the
|
|
threads.
|
|
|
|
.eos.
|
|
|
|
fakesrc detects the end of stream. It just returned the last buffer.
|
|
The next _pull will cause the srcpad to trigger gst_pad_set_eos ().
|
|
After that it will return a NULL buffer.
|
|
|
|
chain1 is taken out of the scheduling algorithm of the bin.
|
|
|
|
after a while, the threads finish their scheduling and fire EOS too.
|
|
chain2 (with queue1) is taken out of the scheduling first because it
|
|
is empty.
|
|
|
|
chain3 (with queue2) finally removes its last scheduled chain and
|
|
fires EOS.
|
|
|
|
The bin now has no more scheduled chains and no more pending subbins,
|
|
it fires EOS.
|
|
|
|
|
|
case 5)
|
|
|
|
(-----------------------------------------------------------------------)
|
|
! bin !
|
|
! (---------------) !
|
|
! !audiosink ! !
|
|
! (--------) (----------) (--------) ! ! !
|
|
! !disksrc1! ! effect ! ! mixer ! ! ! !
|
|
! ! src -- sink src ---- sink src -- sink ! !
|
|
! (--------) (----------) ! ! ! ! !
|
|
! ! ! (---------------) !
|
|
! (--------) (----------) ! ! !
|
|
! !disksrc2! ! effect ! ! ! !
|
|
! ! 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.
|
|
|
|
two chains are detected: disksrc1-effect-mixer-audiosink,
|
|
disksrc2-effect-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 mixer element because it has overridden
|
|
the handler. The first chain is disabled from the scheduler.
|
|
|
|
finally disksrc2 run into EOS, same procedure as with disksrc1, except
|
|
now the mixer also sets EOS to its src pad, chain2 becomes inactive too
|
|
and the bin fires EOS because there are no more chains to schedule.
|
|
|
|
somebody sets the location of disksrc1 to a new mp3 file, the srcpad
|
|
is set to !EOS, chain1 is scheduled again, mixer is activated again too
|
|
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.
|
|
|
|
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.
|
|
|
|
|