所有的 video capture 和 output 装置都必须指定其场的传输顺序,即是 top 场在前还是 bottom 场在时间上和空间 上的顺序 。具体的可以从参考 spec 关于 Field Order 的描述,一般采用的是 V4L2_FIILED_INTERLACED ,在这个模式下 image 包含交叉存取的帧,场的顺序由当前的视频标准来决定。 __u32 bytesperline ...
所有的 video capture 和 output 装置都必须指定其场的传输顺序,即是 top 场在前还是 bottom 场在时间上和空间 上的顺序 。具体的可以从参考 spec 关于 Field Order 的描述,一般采用的是 V4L2_FIILED_INTERLACED ,在这个模式下 image 包含交叉存取的帧,场的顺序由当前的视频标准来决定。 __u32 bytesperline ...
s_fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_JPEG; s_fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;//4 s_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; ret = ioctl(fd,VIDIOC_S_FMT,&s_fmt); 4.申请内核态缓冲 struct v4l2_requestbuffers reqbuf; //memset(&reqbuf,0,sizeof(reqbuf)); reqbuf.coun...
fmt.fmt.pix.height = 480; fmt.fmt.pix.pixelformat = V4L2_FIELD_INTERLACED; // 隔行扫描的方式 /* 设置图像格式 */ ioctl(fd, VIDIOC_S_FMT, &fmt); /* 申请视频缓冲区 */ struct v4l2_requestbuffers req_buf; CLEAR(req_buf); req_buf.count = 10; // 缓冲区大小 req_buf.type = V4L2_B...
enum v4l2_field { V4L2_FIELD_ANY = 0, /* driver can choose from none, top, bottom, interlaced depending on whatever it thinks is approximate ... */ V4L2_FIELD_NONE = 1, /* this device has no fields ... */ V4L2_FIELD_TOP = 2, /* top field only */ ...
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; if (-1 == xioctl(fd1, VIDIOC_S_FMT, &fmt)) errno_exit("VIDIOC_S_FMT"); } else { if (-1 == xioctl(fd1, VIDIOC_G_FMT, &fmt)) errno_exit("VIDIOC_G_FMT"); } fprintf(stdout,"<---camera infomation--->\n"); fprintf(stdout,"de...
#else fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG; #endif /* fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV; */ fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; ret = ioctl(fd, VIDIOC_S_FMT, &fmt); if( ret < 0) { printf("ERROR(%s): ioctl VIDIOC_S_FMT error \n", MODULE_TAG);...
v4l2_field enumv4l2_field{V4L2_FIELD_ANY=0,/* driver can choose from none, top, bottom, interlaced depending on whatever it thinks is approximate ... */V4L2_FIELD_NONE=1,/* this device has no fields ... */V4L2_FIELD_TOP=2,/* top field only */V4L2_FIELD_BOTTOM=3,/* bottom field...
使用举例:-struct v4l2_format tv4l2_format;tv4l2_format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;tv4l2_format.fmt.pix.width = img_width;tv4l2_format.fmt.pix.height = img_height;tv4l2_format.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;tv4l2_format.fmt.pix.field = V4L2_FIELD_INTERLACED;iret = ...
25、lformat = v4l2_pix_fmt_yuyv; fmt.fmt.pix.field = v4l2_field_interlaced; if (ioctl(fd, vidioc_s_fmt, fmt) = -1) return -1; v4l2_format结构如下: struct v4l2_format enum v4l2_buf_type type; / 数据流类型,必需永久是v4l2_buf_type_video_capture union struct v4l2_pix_format pix; ...