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85 lines
3 KiB
Text
85 lines
3 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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! ! 1 src ----- sink 1 src ---- sink 1 ! !
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! (--------) (--------) (--------) !
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! !
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! (--------) (--------) (--------) !
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! !fakesrc ! !identity! !fakesink! !
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! ! 2 src ----- sink 2 src ---- sink 2 ! !
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! (--------) (--------) (--------) !
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(--------------------------------------------------)
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just two scheduled chains in a single bin.
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.scheduling.
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we have two chains here fs1-i1-fsk1 and fs2-i2-fsk2
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fakesrc1 will output 1 buffer, fakesrc2 3 buffers
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.eos.
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fs1 will call gst_pad_set_eos (src, TRUE) on its srcpad
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in the _get function and returns a NULL buffer.
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gst_pad_set_eos will recurse down the pipeline and set
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all the pads in i1 and fsk1 to EOS too. none of these elements
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override the default behaviour so gst_pad_set_eos returns TRUE.
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fakesrc signals EOS. since an element in chain1 has signales
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EOS, chain1 becomes EOS. All the elements in the chain are set
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to the READY state and the chain is not scheduled anymore because
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its EOS flag is on.
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the same procedure happens for chain2. At that point, the bin
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has no chains to schedule and so it fires EOS.
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case 2)
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(---------------------------------------------------)
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! bin !
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! (--------) (--------) (---------) !
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! ! disksrc! ! mpg123 ! !audiosink! !
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! ! 1 src ----- sink 1 src ---- sink 1 ! !
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! (--------) (--------) (---------) !
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! !
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! (--------) (--------) (---------) !
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! !disksrc ! ! mpg123 ! !audiosink! !
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! ! 2 src ----- sink 2 src ---- sink 2 ! !
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! (--------) (--------) (---------) !
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(---------------------------------------------------)
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same as case 1, an mp3 mixer where the mixing is performed
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in hardware (in the audiosink).
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we want to show how the EOS state can be undone.
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.scheduling.
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we have two chains here ds1-mpg1-ask1 and ds2-mpg2-ask2
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the song in chain1 is about to end, chain2 has just begun
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playing a song.
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.eos.
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disksrc1 will set the src pad to EOS with gst_pad_set_eos (pad, TRUE)
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the call recurses up and down, disksrc1 signals EOS. the chain with
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disksrc1 becomes EOS and is excluded from the scheduling algorithm.
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disksrc1 is set to the READY state.
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the user then changes the location of disksrc1 to the new mp3 song.
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The user then sets the element state of disksrc to PLAYING. disksrc
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performs gst_pad_set_eos (pad, FALSE)
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the call recurses up and down and returns TRUE. chain1 is set to !EOS
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so that it will be scheduled again.
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disksrc1 is set to PLAYING and the new mp3 is playing again.
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