这部分涉及不少专业支持,有些可能写的不好,请大家原谅!
/* Values for 'capabilities' field */
#define V4L2_CAP_VIDEO_CAPTURE 0x00000001 /* Is a video capture device */
#define V4L2_CAP_VIDEO_OUTPUT 0x00000002 /* Is a video output device */
#define V4L2_CAP_VIDEO_OVERLAY 0x00000004 /* Can do video overlay */
#define V4L2_CAP_VBI_CAPTURE 0x00000010 /* Is a raw VBI capture device */
#define V4L2_CAP_VBI_OUTPUT 0x00000020 /* Is a raw VBI output device */
#define V4L2_CAP_SLICED_VBI_CAPTURE 0x00000040 /* Is a sliced VBI capture device */
#define V4L2_CAP_SLICED_VBI_OUTPUT 0x00000080 /* Is a sliced VBI output device */
#define V4L2_CAP_RDS_CAPTURE 0x00000100 /* RDS data capture */
#define V4L2_CAP_VIDEO_OUTPUT_OVERLAY 0x00000200 /* Can do video output overlay */
#define V4L2_CAP_HW_FREQ_SEEK 0x00000400 /* Can do hardware frequency seek */
#define V4L2_CAP_RDS_OUTPUT 0x00000800 /* Is an RDS encoder */
/* Is a video capture device that supports multipl