函数 sws_test_primaries 

pub unsafe extern "C" fn sws_test_primaries(
    primaries: AVColorPrimaries,
    output: c_int,
) -> c_int

Test if a given set of color primaries is supported.

@param output If 0, test if compatible with the source/input frame; otherwise, with the destination/output frame. @param primaries The color primaries to check.

@return A positive integer if supported, 0 otherwise.