Messages have ever-incrementing sequence numbers, which may also be set
explicitly via gst_message_set_seqnum(). Sequence numbers are typically used
to indicate that a message corresponds to some other set of messages or
events, for example a SEGMENT_DONE message corresponding to a SEEK event. It
is considered good practice to make this correspondence when possible, though
it is not required.
Note that events and messages share the same sequence number incrementor;
two events or messages will never have the same sequence number unless
that correspondence was made explicitly.
Retrieve the sequence number of a message.
Messages have ever-incrementing sequence numbers, which may also be set explicitly via gst_message_set_seqnum(). Sequence numbers are typically used to indicate that a message corresponds to some other set of messages or events, for example a SEGMENT_DONE message corresponding to a SEEK event. It is considered good practice to make this correspondence when possible, though it is not required.
Note that events and messages share the same sequence number incrementor; two events or messages will never have the same sequence number unless that correspondence was made explicitly.
Return: The message's sequence number.
MT safe.