c语言 error redefinition of 'xxx' 解决

头文件定义报错：error redefinition of 'xxx'

typedef struct wzmedia_echo_state

{
    char     *obj_name;
    unsigned     samples_per_frame;
    void         *state;


    short     lat_ready;    /* lat_buf has been filled in.   */
    struct frame     lat_buf;    /* Frame queue for lattency playback   */
    short         *frm_buf;
    unsigned int lat_time;
    unsigned int played_time;

}wzmedia_echo_state;

重复定义错误，头文件修改后：

#ifndef _COMMON
#define _COMMON

typedef struct wzmedia_echo_state

{
    char       *obj_name;
    unsigned      samples_per_frame;
    void          *state;


    short       lat_ready;     /* lat_buf has been filled in.    */
    struct frame     lat_buf;     /* Frame queue for lattency playback    */
    short          *frm_buf;
    unsigned int  lat_time;
    unsigned int   played_time;

}wzmedia_echo_state;

#endif