typedef struct {    void *faust;    int argpos;    SPFLOAT *args[4];    SPFLOAT *ratio;    SPFLOAT *thresh;    SPFLOAT *atk;    SPFLOAT *rel;} sp_compressor; int sp_compressor_create(sp_compressor **p);int sp_compressor_destroy(sp_compressor **p);int sp_compressor_init(sp_data *sp, sp_compressor *p);int sp_compressor_compute(sp_data *sp, sp_compressor *p, SPFLOAT *in, SPFLOAT *out);