module_need(vlc_object_t *obj, const char *cap, const char *name,
bool strict)
->vlc_module_load(obj, cap, name, strict, generic_start, obj);
->ssize_t total = module_list_cap (&mods, capability);
example: core scale: looking for video filter2 module matching "any": 36 candidates
cap=video filter2,name=any,total=36
module_list_cap:bank.c
The list is sorted from the highest module score to the lowest.
->module_load
set_capability 设置score
