Function av_expr_count_func

pub unsafe extern "C" fn av_expr_count_func(
    e: *mut AVExpr,
    counter: *mut u32,
    size: i32,
    arg: i32,
) -> i32

Track the presence of user provided functions and their number of occurrences in a parsed expression.

@param e the AVExpr to track user provided functions in @param counter a zero-initialized array where the count of each function will be stored if you passed 5 functions with 2 arguments to av_expr_parse() then for arg=2 this will use up to 5 entries. @param size size of array @param arg number of arguments the counted functions have @return 0 on success, a negative value indicates that no expression or array was passed or size was zero