How Flink encodes state data in CEP scenario?

Question

I am using Flink CEP to recognize some event patterns, the query looks like

select * from $TABLE
    MATCH_RECOGNIZE(
        partition by $PARTITION_FIELDS
        order by event_time
        measures
            ...
        one row per match
        after match SKIP past LAST ROW
        pattern(...) within interval '1' minute
        define
            ...
    )

I enabled RocksDB state backend. I would like to check what the state data look like in RocksDB. By using RocksDB's Java API, the state data was retrieved successfully, however they are encoded.

I would like to know how and where Flink encodes those state data.

Thanks