Creates a stream-id for the source Pad this by combining the
upstream information with the optional stream_id of the stream of this.
this must have a parent Element and which must
have zero or one sinkpad. stream_id can only be null if the parent element of this
has only a single source pad.
This function generates an unique stream-id by getting the upstream stream-start event stream ID and appending stream_id to
it. If the element has no sinkpad it will generate an upstream stream-id by doing an URI query on the element and in the worst case just
uses a random number. Source elements that don't implement the URI handler interface should ideally generate a unique, deterministic
stream-id manually instead.
| this |
A source Pad |
| parent |
Parent Element of this |
| stream_id |
The stream-id |
| var_args |
parameters for the |
|
A stream-id for this. g_free after usage. |