Lifetimes¶
![digraph SEQ_DIAGRAM {
graph [overlap=true, splines=line, nodesep=1.0, ordering=out];
edge [arrowhead=none];
node [shape=none, width=0, height=0, label=""];
{
rank=same;
node[shape=rectangle, height=0.7, width=2];
state_null[label="State NULL"];
state_ready[label="State READY"];
api_c[label="State PAUSED"];
state_play[label="State PLAYING"];
}
// Draw vertical lines
{
edge [style=dashed, weight=6];
state_null -> a1 -> a2 -> a3;
a3 -> a4;
a4 -> a5 -> a6;
// a5 -> a6;
}
{
edge [style=dashed, weight=6];
state_ready -> b1;
b1 -> b2 [penwidth=5, style=solid];
b2 -> b3 -> b4;
b4 -> b5 ;
b5 -> b6[penwidth=5; style=solid];
}
{
edge [style=dashed, weight=6];
api_c -> c1 -> c2;
c2 -> c3 [penwidth=5, style=solid];
c3 -> c4;
c4 -> c5 [penwidth=5, style=solid];
c5 -> c6 -> c7;
}
{
edge [style=dashed, weight=6];
state_play -> d1 -> d2 -> d3
d3 -> d4 [penwidth=5, style=solid];
d4 -> d5 -> d6;
}
// Draws activations
{
rank=same; a1 -> b1 [label="open-device", arrowhead=normal];
}
{ rank=same; a2 -> b2 [style=invis]; b2 -> c2 [label="configuration", arrowhead=normal]; }
{ rank=same; c3 -> d3 [arrowhead=normal, label="PLAY()"]; }
{ rank=same; c4 -> d4 [arrowhead=normal, label="PAUSE()", dir=back]; }
{ rank=same; b5 -> c5 [arrowhead=normal, label="READY()", dir=back]; }
{ rank=same; a6 -> b6 [label="close-device", arrowhead=normal, dir=back]; }
}](_images/graphviz-b7d555af638ecb3ee8affad2c3c02b282f6871a4.png)
This page explains the lifetimes of various elements/properties.
GST_STATE_NULL -> GST_STATE_READY¶
Upon entering this state a device will be opened by the tcamsrc. If the requested device cannot be found or opened a GST_STATE_CHANGE_FAILURE will be returned.
tcamconvert/tcamdutils/tcamdutils-cuda will be initialized.
All properties will be available.
GST_STATE_READY -> GST_STATE_PAUSED¶
- tcambin device-caps will be fixed and set for the internal tcamsrc. - if no device-caps are set, auto negotiation will determine caps and set them.
- if tcambin tcam-properties-json is set, the properties will be applied.
GST_STATE_PAUSED -> GST_STATE_PLAYING¶
Start image retrieval.
GST_STATE_PLAYING -> GST_STATE_PAUSED¶
GST_STATE_PAUSED -> GST_STATE_READY¶
GST_STATE_READY -> GST_STATE_NULL¶
- All property objects are invalid and should be discarded. Using property functions will return TCAM_ERROR_NO_DEVICE_OPEN.
- All tcambin internal elements will be discarded.
- The tcambin source element will be discarded. This closes the camera.
- The tcamsrc will close the hardware device.