struct v4l2_input

最新推荐文章于 2024-07-31 08:47:03 发布

原创最新推荐文章于 2024-07-31 08:47:03 发布 · 3.5k 阅读

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#struct #input #output #access #signal #file

本文介绍了 V4L2 (Video for Linux Version 2) 中的输入输出结构定义，详细阐述了 v4l2_input 和 v4l2_output 结构体的各个字段含义及其枚举值，同时给出了一个具体的枚举输入实例。

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/*
 *	V I D E O   I N P U T S
 */
struct v4l2_input {
	__u32	     index;		/*  Which input */
	__u8	     name[32];		/*  Label */
	__u32	     type;		/*  Type of input */
	__u32	     audioset;		/*  Associated audios (bitfield) */
	__u32        tuner;             /*  Associated tuner */
	v4l2_std_id  std;
	__u32	     status;
	__u32	     reserved[4];
};

/*  Values for the 'type' field */
#define V4L2_INPUT_TYPE_TUNER		1
#define V4L2_INPUT_TYPE_CAMERA		2

/* field 'status' - general */
#define V4L2_IN_ST_NO_POWER    0x00000001  /* Attached device is off */
#define V4L2_IN_ST_NO_SIGNAL   0x00000002
#define V4L2_IN_ST_NO_COLOR    0x00000004

/* field 'status' - sensor orientation */
/* If sensor is mounted upside down set both bits */
#define V4L2_IN_ST_HFLIP       0x00000010 /* Frames are flipped horizontally */
#define V4L2_IN_ST_VFLIP       0x00000020 /* Frames are flipped vertically */

/* field 'status' - analog */
#define V4L2_IN_ST_NO_H_LOCK   0x00000100  /* No horizontal sync lock */
#define V4L2_IN_ST_COLOR_KILL  0x00000200  /* Color killer is active */

/* field 'status' - digital */
#define V4L2_IN_ST_NO_SYNC     0x00010000  /* No synchronization lock */
#define V4L2_IN_ST_NO_EQU      0x00020000  /* No equalizer lock */
#define V4L2_IN_ST_NO_CARRIER  0x00040000  /* Carrier recovery failed */

/* field 'status' - VCR and set-top box */
#define V4L2_IN_ST_MACROVISION 0x01000000  /* Macrovision detected */
#define V4L2_IN_ST_NO_ACCESS   0x02000000  /* Conditional access denied */
#define V4L2_IN_ST_VTR         0x04000000  /* VTR time constant */

/*
 *	V I D E O   O U T P U T S
 */
struct v4l2_output {
	__u32	     index;		/*  Which output */
	__u8	     name[32];		/*  Label */
	__u32	     type;		/*  Type of output */
	__u32	     audioset;		/*  Associated audios (bitfield) */
	__u32	     modulator;         /*  Associated modulator */
	v4l2_std_id  std;
	__u32	     reserved[4];
};
/*  Values for the 'type' field */
#define V4L2_OUTPUT_TYPE_MODULATOR		1
#define V4L2_OUTPUT_TYPE_ANALOG			2
#define V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY	3

static int s3c2410camif_vidioc_enum_input(struct file *file,
                void *priv, struct v4l2_input *input)
{
	if (input->index != 0)
		return -EINVAL;

	strcpy(input->name, "S3C2410 Camera");
	input->type = V4L2_INPUT_TYPE_CAMERA;
	return 0;
}