emit a \bt_sb_msg for this stream before you emit any other
message for this stream.
The stream beginning message must have a
\ref api-msg-sb-prop-cs "default clock snapshot" which corresponds
emit a \bt_sb_msg for this stream before you emit any other
message for this stream.
The stream beginning message must have a
\ref api-msg-sb-prop-cs "default clock snapshot" which corresponds