Nov 2 06:05:53 linux11 kernel: [128353.599890] end_request: I/O error, dev sda, sector 3868680127 Nov 2 06:05:53 linux11 kernel: [128353.599893] Buffer I/O error on device sda1, logical block 483585008 Nov 2 06:05:53 linux11 kernel: [128353.599895] lost page write due to I/O er...
在V4L2中,时间戳通常与视频缓冲区(v4l2_buffer结构体)相关联。以下是一个简单的示例,展示了如何获取和使用V4L2时间戳: c #include <linux/videodev2.h> #include <sys/ioctl.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h...
TIMESTAMPDIFF函数允许其搭配使用的参数datetime_expr1和datetime_expr2具有混合类型 datetime_expr1是DATE类型值,datetime_expr2是DATETIME类型值, TIMESTAMPDIFF函数会将datetime_expr1自动转换成DATETIME类型值 (即在日期后面加上时间“00:00:00”) -- 12 SELECT TIMESTAMPDIFF(HOUR,'2022-04-27','2022-04-27 ...
buffer:驱动中的一帧图像缓存,对应命令VIDIOC_QUERYBUF index:编号 type:视频捕获模式 bytesused:缓存已使用空间大小 flags:当前状态,常见有V4L2_BUF_FLAG_|V4L2_BUF_FLAG_QUEUED|V4L2BUF_FLAG_DONE,分别表示当前缓存已经映射,缓存可以采集数据,缓存可以提取数据。 timestamp:时间戳 sequence:缓存序号 memory...
struct v4l2_buffer { __u32 index; __u32 type; __u32 bytesused; __u32 flags; __u32 field; struct timeval timestamp; struct v4l2_timecode timecode; __u32 sequence; /* memory location */ __u32 memory; union { __u32 offset; ...
我们首先通过v4l2_buffer结构体看看参数三这个输入输出参数需要输入些什么,以及能够得到什么信息。 struct v4l2_buffer { __u32 index; enum v4l2_buf_type type; __u32 bytesused; __u32 flags; enum v4l2_field field; struct timeval timestamp;
4.v4l2_buffer 缓冲区结构体 struct v4l2_buffer { __u32 index; enum v4l2_buf_type type; __u32 byteSUSEd; __u32 flags; enum v4l2_field field; struct timeval timestamp; struct v4l2_timecode timecode; __u32 sequence; /* memory location */ ...
structv4l2_bufferbuf; structbuffer { void* start; unsignedintlength; longlonginttimestamp; } *buffers; intv4l2_init() { structv4l2_capabilitycap; structv4l2_fmtdescfmtdesc; structv4l2_formatfmt; structv4l2_streamparmstream_para; //打开摄像头设备 ...
01struct v4l2_buffer02{03__u32 index;//buffer 序号04enumv4l2_buf_type type;//buffer 类型05__u32 byteused;//buffer 中已使用的字节数06__u32 flags;// 区分是MMAP 还是USERPTR07enumv4l2_field field;08struct timeval timestamp;// 获取第一个字节时的系统时间09struct v4l2_timecode timecode;10...
struct v4l2_buffer buf; //make the v4l call to xioctl(fd, VIDIOC_DQBUF, &buf) //then: long temp_ms = 1000 * buf.timestamp.tv_sec + (long) round( buf.timestamp.tv_usec / 1000.0); long epochTimeStamp_ms = temp_ms + toEpochOffset_ms ; ...