前面使用了v4l2从摄像头获取到一帧图像,格式为JPEG,JPEG是经过压缩后的图像,如果要在LCD上显示,则需要将其解压缩得到RGB数据用于在LCD上显示,解压缩的过程就可以调用libjpeg开源库中的函数来完成解压,得到图像的RGB数据。开源库地址:http:// http://www.ijg.org/files/ 下载源码移植后就可以使用了,在解码中需要...
V4L2_PIX_FMT_RGB32 V4L2_PIX_FMT_YUYV V4L2_PIX_FMT_UYVY V4L2_PIX_FMT_VYUY V4L2_PIX_FMT_YVYU V4L2_PIX_FMT_YUV422P V4L2_PIX_FMT_NV12 V4L2_PIX_FMT_NV12T V4L2_PIX_FMT_NV21 V4L2_PIX_FMT_NV16 V4L2_PIX_FMT_NV61 V4L2_PIX_FMT_YUV420 V4L2_PIX_FMT_JPEG 应用程序使用举例: intv4l2_enum_...
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_JPEG;if (ioctl(fd, VIDIOC_S_FMT, &fmt) < 0）{ printf("set format failed\n");//return 0;} 5. 向驱动申请帧缓冲，一般不超过5个。struct v4l2_requestbuffers struct v4l2_requestbuffers { __u32 count; // 缓存数量，也就是说在缓存队列里保持多少张...
要使用V4L2驱动库生成MJPEG流,初始化步骤要写对: struct v4l2_format fmt; fmt.type = V4L2_CAP_VIDEO_CAPTURE; fmt.fmt.pix.width = IMAGEWIDTH; fmt.fmt.pix.height = IMAGEHEIGHT; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG; IF (ioctl (fd_video, VIDIOC_S_FMT, &fmt) == -1) { perror(...
memset (&fmt, 0, sizeof(fmt) ); fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.width = 320; fmt.fmt.pix.height = 240; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_JPEG; if (ioctl(fd, VIDIOC_S_FMT,&fmt)<0) { printf("set format failed\n"); ...
if (v4l2_fmt.fmt.pix.pixelformat == V4L2_PIX_FMT_MJPEG) { printf("Set VIDIOC_S_FMT sucessful\n"); } // 5、Require buffer to store image data struct v4l2_requestbuffers v4l2_req; v4l2_req.count = NB_BUFFER; v4l2_req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; ...
memset ( &fmt, 0, sizeof(fmt价煤老个越) ); fmt.type= V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.width = 320; fmt.fmt.pix.height = 240; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_JPEG; if (ioctl(fd, VIDIOC_S_FMT, &fmt) < 0) ...
fmt.fmt.pix.priv = 0; fmt.fmt.pix.sizeimage = 0; ioctl(dev->fd, VIDIOC_S_FMT, &fmt); ioctl(dev->fd, VIDIOC_G_FMT, &fmt); 设置视频设备的视频数据格式,例如设置视频图像数据的长、宽,图像格式(JPEG、YUYV格式) 如果该视频设备驱动不支持你所设定的图像格式,视频驱动会重新修改struct v4l2_for...
#define V4L2_PIX_FMT_JPEG v4l2_fourcc('J','P','E','G') #define V4L2_PIX_FMT_DV v4l2_fourcc('d','v','s','d') #define V4L2_PIX_FMT_MPEG v4l2_fourcc('M','P','E','G') #define V4L2_PIX_FMT_WNVA v4l2_fourcc('W','N','V','A') ...
CLEAR (fmt); fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.width = 640; fmt.fmt.pix.height = 480; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_UYVY;//V4L2_PIX_FMT_JPEG; fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; ff = ioctl (fd, VIDIOC_S_FMT, &fmt); ...