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76f1b4540a
Original commit message from CVS: While typing on eos2 about the EOS handling, I got an idea and started eos3. eos3 takes a different approach by merging the eos detection and the scheduling in a quite elegant way. I'm not sure we handle the scheduling like this though...
147 lines
6.1 KiB
Text
147 lines
6.1 KiB
Text
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case 1)
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(--------------------------------------------------)
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! bin !
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! (--------) (--------) (--------) !
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! ! fakesrc! !identity! !fakesink! !
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! ! src ----- sink src ---- sink ! !
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! (--------) (--------) (--------) !
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(--------------------------------------------------)
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.scheduling.
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case1 has just one scheduled entity (chain) no problem here.
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.eos.
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fakesrc detects the end of stream. It just returned the last buffer.
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The next _pull will cause the srcpad to trigger gst_pad_set_eos ().
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After that it will return a NULL buffer.
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gst_pad_set_eos() will notify the parent about the plugins attempt to
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signal eos. the parent adds the element to its possible EOS
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providers.
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gst_pad_set_eos() will by default propagate to identy and to fakesink.
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none of these plugins override the default behaviour so gst_pad_set_eos
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returns TRUE and fakesrc signals EOS with the value TRUE.
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The parent looks in the list of EOS providers and finds the faksrc
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element that is now signaling EOS. all EOS providers are now in EOS
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and so the bin fires EOS.
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case 2)
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(---------------)
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!thread !
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(--------) (--------) (--------) ! (--------)!
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! fakesrc! !identity! ! queue ! ! !fakesink!!
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! src ----- sink src ---- sink src ---- sink !!
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(--------) (--------) (--------) ! (--------)!
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(---------------)
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.scheduling.
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case2 has two scheduled entities: fsr-i-q, q-fsk.
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.eos.
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fakesrc detects the end of stream. It just returned the last buffer.
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The next _pull will cause the srcpad to trigger gst_pad_set_eos ().
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After that it will return a NULL buffer.
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gst_pad_set_eos() will notify the parent about the plugins attempt to
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signal eos. the parent adds the element to its possible EOS
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providers.
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gst_pad_eos() will by default propagate to identy and to queue.
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queue overrides the eos handler and returns false on the eos
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request. fakesrc signals EOS with a value of false and the parent
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bin removes the EOS provider from its list.
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after the queue has sent out the last buffer, its calls eos on its
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src pad. queue is added to the top level bin as an eos provider and
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the default eos handler signals EOS with a value of TRUE to the parent.
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the parent sees that all the eos providers are in eos now and signals
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EOS.
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case 3)
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(---------------)
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!thread !
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(--------) (--------) (--------) ! (--------)!
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! fakesrc! ! tee ! ! queue1 ! ! !fakesink!!
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! src ----- sink src ---- sink src ---- sink !!
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(--------) ! ! (--------) ! (--------)!
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! ! (---------------)
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! !
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! ! (---------------)
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! ! !thread !
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! ! (--------) ! (--------)!
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! ! ! queue2 ! ! !fakesink!!
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! src ---- sink src ---- sink !!
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! ! (--------) ! (--------)!
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(--------) (---------------)
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fakesrc detects the end of stream. It just sent the last buffer
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and sets the srcpad to EOS with gst_pad_eos ().
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the eos handler returns false because both queues return false on the
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eos request. the parent removes fakesrc as an EOS provider.
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queue1 and queue2 were responisble for the EOS delay and so they get
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added to the bin as possible EOS providers.
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after the queues have sent out their last buffer, they calls eos on their
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src pads.
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the parent allready has the two queues in the EOS provider list so they dont
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get added twice.
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the two queues perform gst_pad_eos () on their pads when the queue is empty,
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the parent removes the EOS providers from its list, when the list is empty,
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the parent fires EOS.
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case 4)
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(---------------)
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!thread !
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(--------) (----------) (--------) ! (--------)!
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! fakesrc! !mpeg1parse! ! queue1 ! ! !fakesink!!
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! src -- sink src ---- sink src ---- sink !!
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(--------) ! ! (--------) ! (--------)!
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! ! (---------------)
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! !
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! ! (---------------)
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! ! !thread !
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! ! (--------) ! (--------)!
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! ! ! queue2 ! ! !fakesink!!
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! src ---- sink src ---- sink !!
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! ! (--------) ! (--------)!
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(----------) (---------------)
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this case differs from case3 in that one of the queues can be empty
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while the other isn't. we assume queue1 is empty while queue2 isn't yet.
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fakesrc detects the end of stream. It just sent the last buffer
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and sets the srcpad to EOS with gst_pad_eos ().
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the eos handler returns false because queue2 returns false on the
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eos request. the parent removes fakesrc as an EOS provider.
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queue2 was responisble for the EOS delay and so it gets added to the bin
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as a possible EOS provider.
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after the queue2 has sent its last buffer, it performs gst_pad_eos on its
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src pad.
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the parent allready has the queue2 in the list of EOS providers so it does not
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get added twice.
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queue2 finally fires the EOS signal and the parent removes the EOS provider
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from its list, when the list is empty, the parent fires EOS.
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