Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_57 ( compression_ratio VARCHAR, dx_10_name VARCHAR, fourcc VARCHAR )

### Question ###
Which Compression ratio has a (none) DX 10 Name and a FOURCC of dxt4?

### Accurate SQL ###

SELECT compression_ratio FROM table_name_57 WHERE dx_10_name = "(none)" AND fourcc = "dxt4"