Event.this

Create a new STREAM_START event. The stream start event can only travel downstream synchronized with the buffer flow. It is expected to be the first event that is sent for a new stream. Source elements, demuxers and other elements that create new streams are supposed to send this event as the first event of a new stream. It should not be send after a flushing seek or in similar situations and is used to mark the beginning of a new logical stream. Elements combining multiple streams must ensure that this event is only forwarded downstream once and not for every single input stream. The stream_id should be a unique string that consists of the upstream stream-id, / as separator and a unique stream-id for this specific stream. A new stream-id should only be created for a stream if the upstream stream is split into (potentially) multiple new streams, e.g. in a demuxer, but not for every single element in the pipeline. gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be used to create a stream-id.