1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
OUTDATED
--------
case 1)
(--------) (--------) (--------)
! fakesrc! !identity! !fakesink!
! src ----- sink src ---- sink !
(--------) (--------) (--------)
fakesrc detects the end of stream. It just sent the last buffer
and sets the srcpad to EOS with gst_pad_eos ().
gst_pad_eos() will notify the parent about the plugins attempt to
signal eos. the parent adds the element to its possible EOS
providers.
gst_pad_eos() will by default propagate to identy and to fakesink.
none of these plugins override the default behaviour so gst_pad_eos
returns TRUE and fakesrc signals EOS with the value TRUE.
The parent looks in the list of EOS providers and finds the faksrc
element that is now signaling EOS. all EOS providers are now in EOS
and so the bin fires EOS.
case 2)
(---------------)
!thread !
(--------) (--------) (--------) ! (--------)!
! fakesrc! !identity! ! queue ! ! !fakesink!!
! src ----- sink src ---- sink src ---- sink !!
(--------) (--------) (--------) ! (--------)!
(---------------)
fakesrc detects the end of stream. It just sent the last buffer
and sets the srcpad to EOS with gst_pad_eos ().
gst_pad_eos() will notify the parent about the plugins attempt to
signal eos. the parent adds the element to its possible EOS
providers.
gst_pad_eos() will by default propagate to identy and to queue.
queue overrides the eos handler and returns false on the eos
request. fakesrc signals EOS with a value of false and the parent
bin removes the EOS provider from its list.
after the queue has sent out the last buffer, its calls eos on its
src pad. queue is added to the top level bin as an eos provider and
the default eos handler signals EOS with a value of TRUE to the parent.
the parent sees that all the eos providers are in eos now and signals
EOS.
case 3)
(---------------)
!thread !
(--------) (--------) (--------) ! (--------)!
! fakesrc! ! tee ! ! queue1 ! ! !fakesink!!
! src ----- sink src ---- sink src ---- sink !!
(--------) ! ! (--------) ! (--------)!
! ! (---------------)
! !
! ! (---------------)
! ! !thread !
! ! (--------) ! (--------)!
! ! ! queue2 ! ! !fakesink!!
! src ---- sink src ---- sink !!
! ! (--------) ! (--------)!
(--------) (---------------)
fakesrc detects the end of stream. It just sent the last buffer
and sets the srcpad to EOS with gst_pad_eos ().
the eos handler returns false because both queues return false on the
eos request. the parent removes fakesrc as an EOS provider.
queue1 and queue2 were responisble for the EOS delay and so they get
added to the bin as possible EOS providers.
after the queues have sent out their last buffer, they calls eos on their
src pads.
the parent allready has the two queues in the EOS provider list so they dont
get added twice.
the two queues perform gst_pad_eos () on their pads when the queue is empty,
the parent removes the EOS providers from its list, when the list is empty,
the parent fires EOS.
case 4)
(---------------)
!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.
fakesrc detects the end of stream. It just sent the last buffer
and sets the srcpad to EOS with gst_pad_eos ().
the eos handler returns false because queue2 returns false on the
eos request. the parent removes fakesrc as an EOS provider.
queue2 was responisble for the EOS delay and so it gets added to the bin
as a possible EOS provider.
after the queue2 has sent its last buffer, it performs gst_pad_eos on its
src pad.
the parent allready has the queue2 in the list of EOS providers so it does not
get added twice.
queue2 finally fires the EOS signal and the parent removes the EOS provider
from its list, when the list is empty, the parent fires EOS.
case 5)
(--------) (--------) (--------)
! disksrc! ! mad ! !filesink!
! src ----- sink src ---- sink !
(--------) (--------) (--------)
disksrc detects the end of stream. It just sent the last buffer
and sets the srcpad to EOS with gst_pad_eos ().
the eos handler returns false because mad returns false on the
eos request. the parent removes mad as an EOS provider.
mad was responsible for the EOS delay and so it gets added to the bin
as a possible EOS provider.
After mad has sent its last buffer, it performs gst_pad_eos on its
src pad.
the parent already has mad in the list of EOS providers so it does not
get added twice.
mad finally fires the EOS signal. This time, filesink returns false on
the eos request. the parent removes mad as an EOS provider.
filesink was responsible for the EOS delay and gets added to the bin
as a possible EOS provider.
When filesink has written all of it's data and closed the output file,
it fires EOS.
The parent already has filesink in the list of EOS providers so it does
not get added twice.
The parent removes the EOS provider
from its list, and since the list is empty, the parent fires EOS.
case 6)
(--------) (--------) (--------)
!disksrc1! ! mad1 ! ! mixer !
! src ----- sink src ---- sink1 ! (--------)
(--------) (--------) ! ! !filesink!
! src ---- sink !
(--------) (--------) ! ! (--------)
!disksrc2! ! mad2 ! ! !
! src ----- sink src ---- sink2 !
(--------) (--------) (--------)
In this case, we want to make sure the pipeline keeps running after one
of the two sources reaches eos. Suppose in this case that disksrc1 will
reach eos first.
disksrc1 detects the end of stream. It sets eos, mad1 will return false,
and mad1 will be responsible for eos. When mad1 had sent out the last
buffer, it sends out eos.
The mixer intercepts eos and returns false. mad1 is removed from the
eos providers and mixer is added.
(At this point, the mixer might choose to disconnect mad1->src and
mixer->sink1 pads, since it's received eos on mad1->src)
mixer will not send out eos since it hasn't received eos from
mad2->src.
After a while, disksrc2 will detect end of stream, and eos will finally
propagate to mixer. mixer might disconnect mad->src2, and after
realizing all of it's sources have reached eos, it sends out the final
buffer and fires EOS.
At this point, filesink will return false, mixer will be removed as an
eos provider, and filesink will write out it's final buffer and close
the file on disk. At this point, it fires eos, and since it's the last
eos provider, the parent can fire eos.
|
