ref: d8ddc90c497260a1f22cfbbc72c58ba1434eb366
dir: /h/thresh.h/
typedef struct { int init; SPFLOAT prev, thresh, mode; } sp_thresh; int sp_thresh_create(sp_thresh **p); int sp_thresh_destroy(sp_thresh **p); int sp_thresh_init(sp_data *sp, sp_thresh *p); int sp_thresh_compute(sp_data *sp, sp_thresh *p, SPFLOAT *in, SPFLOAT *out);