struct v4l2_buffer

• struct v4l2_buffer

struct v4l2_buffer

struct v4l2_buffer {  
    __u32                   index;    //缓存编号
    enum v4l2_buf_type      type;  //视频捕获模式
    __u32                   bytesused;  //缓存已使用空间大小
    __u32                   flags;  //缓存当前状态
/*
    flags 为缓存当前状态（常见值有 V4L2_BUF_FLAG_MAPPED              | V4L2_BUF_FLAG_QUEUED | V4L2_BUF_FLAG_DONE，分别代表当前缓存已经    映射、缓存可以采集数据、缓存可以提取数据）
*/
    enum v4l2_field         field;  
    struct timeval          timestamp;  
    struct v4l2_timecode    timecode;  
    __u32                   sequence;  
  
    /* memory location */  
    enum v4l2_memory        memory;  
    union {  
            __u32           offset;  
            unsigned long   userptr;  
    } m;  
    __u32                   length;  
    __u32                   input;  
    __u32                   reserved;  
};