函数 av_hwdevice_get_type_name 

pub unsafe extern "C" fn av_hwdevice_get_type_name(
    type_: AVHWDeviceType,
) -> *const c_char

Get the string name of an AVHWDeviceType.

@param type Type from enum AVHWDeviceType. @return Pointer to a static string containing the name, or NULL if the type is not valid.