create_stream_id_printf

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.

Parameters:

this	A source Pad
parent	Parent Element of this
stream_id	The stream-id
...	parameters for the stream_id format string

Returns:

A stream-id for this. g_free after usage.