v4l2_test.tar.gz_v4l2_v4l2 camera

/* 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 */ //#define V4L2_CAP_TUNER 0x00010000 /* has a tuner */ //#define V4L2_CAP_AUDIO 0x00020000 /* has audio support */ //#define V4L2_CAP_RADIO 0x00040000 /* is a radio device */ //#define V4L2_CAP_MODULATOR 0x00080000 /* has a modulator */ //#define V4L2_CAP_READWRITE 0x01000000 /* read/write systemcalls */ //#define V4L2_CAP_ASYNCIO 0x02000000 /* async I/O */ //#define V4L2_CAP_STREAMING 0x04000000 /* streaming I/O ioctls */ #include <stdio.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <fcntl.h> #include <errno.h> #include <sys/mman.h> #include <linux/videodev2.h> #define VIDEO_DEV "/dev/video0" int g_videofd = -1; struct v4l2_buffer buf; //打开设备 int open_device(void) { g_videofd = open(VIDEO_DEV,O_RDWR); if(g_videofd == -1){ perror("open"); return -1; } return 0; } //关闭设备 void close_device(void) { close(g_videofd); } //查询设备功能信息 int cap_deviceinfo(void) { struct v4l2_capability cap; if(ioctl(g_videofd, VIDIOC_QUERYCAP, &cap) < 0){ perror("ioctl"); return -1; } else{ printf("=====================================\n"); printf("driver:\t\t%s\n",cap.driver); printf("card:\t\t%s\n",cap.card); printf("bus_info:\t%s\n",cap.bus_info); printf("version:\t%d\n",cap.version); printf("capabilities:\t%#x\n",cap.capabilities); } //1 if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == V4L2_CAP_VIDEO_CAPTURE) { printf("Device %s: supports capture.\n", VIDEO_DEV); } //2 if ((cap.capabilities & V4L2_CAP_VIDEO_OUTPUT) == V4L2_CAP_VIDEO_OUTPUT) { printf("Device %s: supports output.\n", VIDEO_DEV); } //3 if ((cap.capabilities & V4L2_CAP_VIDEO_OVERLAY) == V4L2_CAP_VIDEO_OVERLAY) { printf("Device %s: supports overlay.\n", VIDEO_DEV); } //4 if ((cap.capabilities & V4L2_CAP_VBI_CAPTURE) == V4L2_CAP_VBI_CAPTURE) { printf("Device %s: supports vbi capture.\n", VIDEO_DEV); } //5 if ((cap.capabilities & V4L2_CAP_VBI_OUTPUT) == V4L2_CAP_VBI_OUTPUT) { printf("Device %s: supports vbi output.\n", VIDEO_DEV); } //6 if ((cap.capabilities & V4L2_CAP_SLICED_VBI_CAPTURE) == V4L2_CAP_SLICED_VBI_CAPTURE) { printf("Device %s: supports sliced vbi capture.\n", VIDEO_DEV); } //7 if ((cap.capabilities & V4L2_CAP_SLICED_VBI_OUTPUT) == V4L2_CAP_SLICED_VBI_OUTPUT) { printf("Device %s: supports sliced sliced vbi output.\n", VIDEO_DEV); } //8 if ((cap.capabilities & V4L2_CAP_RDS_CAPTURE) == V4L2_CAP_RDS_CAPTURE) { printf("Device %s: supports rds capture.\n", VIDEO_DEV); } //9 if ((cap.capabilities & V4L2_CAP_VIDEO_OUTPUT_OVERLAY) == V4L2_CAP_VIDEO_OUTPUT_OVERLAY) { printf("Device %s: supports video output overlay.\n", VIDEO_DEV); } //10 if ((cap.capabilities & V4L2_CAP_HW_FREQ_SEEK) == V4L2_CAP_HW_FREQ_SEEK) { printf("Device %s: supports hw freq seek.\n", VIDEO_DEV); } //11 if ((cap.capabilities & V4L2_CAP_RDS_OUTPUT) == V4L2_CAP_RDS_OUTPUT) { printf("Device %s: supports rds output.\n", VIDEO_DEV); } //12 if ((cap.capabilities & V4L2_CAP_TUNER) == V4L2_CAP_TUNER) { printf("Device %s: supports tuner.\n", VIDEO_DEV); } //13 if ((cap.capabilities & V4L2_CAP_AUDIO) == V4L2_CAP_AUDIO) { printf("Device %s: supports audio.\n", VIDEO_DEV); } //14 if ((cap.capabilities & V4L2_CAP_RADIO) == V4L2_CAP_RADIO) { printf("Device %s: supports radio.\n", VIDEO_DEV); } //15 if ((cap.capabilities & V4L2_CAP_MODULATOR) == V4L2_CAP_MODULATOR) { printf("Device %s: supports modulator.\n", VIDEO_DEV); } //16 if ((cap.capabilities & V4L2_CAP_READWRITE) == V4L2_CAP_READWRITE) { printf("Device %s: supports readwrite.\n", VIDEO_DEV); } //17 if((cap.capabilities & V4L2_CAP_ASYNCIO) == V4L2_CAP_ASYNCIO) { printf("Device %s: supports asyncio.\n",VIDEO_DEV); } //18 if((cap.capabilities & V4L2_CAP_STREAMING) == V4L2_CAP_STREAMING) { printf("Device %s: supports streaming.\n",VIDEO_DEV); } return 0; } //初始化设备信息 int init_V4L2(void) { if(open_device() < 0) return -1; if(cap_deviceinfo() < 0) return -1; return 0; } //获取当前视频设备支持的格式 int get_enum_fmt(void) { struct v4l2_fmtdesc fmtdesc; memset(&fmtdesc,0,sizeof(struct v4l2_fmtdesc)); fmtdesc.index = 0; fmtdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; while(ioctl(g_videofd,VIDIOC_ENUM_FMT,&fmtdesc) != -1) { /*if(ioctl(g_videofd,VIDIOC_ENUM_FMT,&fmtdesc) < 0) { perror("ioctl enum fmt"); return -1; } */ //fmtdesc.index++; printf("====================================\n"); printf("index is %x\n",fmtdesc.index); printf("type is %x\n",fmtdesc.type); printf("flags is %#x\n",fmtdesc.flags); printf("description is %s\n",fmtdesc.description); //printf("pixelformat is %#x\n",fmtdesc.pixelformat); printf("pixelformat is %c %c %c %c\n", fmtdesc.pixelformat & 0xFF, (fmtdesc.pixelformat >> 8) & 0xFF, (fmtdesc.pixelformat >> 16) & 0xFF, (fmtdesc.pixelformat >> 24) & 0xFF); fmtdesc.index++; } return 0; } //获取当前的视频格式以及信息 int get_fmt() { struct v4l2_format format; format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; if(ioctl(g_videofd,VIDIOC_G_FMT,&format) < 0) { perror("get fmt"); return -1; } // struct v4l2_pix_format pix_format; // pixformat = format.fmt.pix; printf("========================================\n"); printf("width:%d\n",format.fmt.pix.width); printf("height:%d\n",format.fmt.pix.height); //printf("pixelformat:%x\n",format.fmt.pix.pixelformat); printf("pixelformat is %c %c %c %c\n", format.fmt.pix.pixelformat & 0xFF, (format.fmt.pix.pixelformat >> 8) & 0xFF, (format.fmt.pix.pixelformat >> 16) & 0xFF, (format.fmt.pix.pixelformat >> 24) & 0xFF); switch(format.fmt.pix.field) { case V4L2_FIELD_ANY: printf("V4L2_FIELD_ANY\n"); break; case V4L2_FIELD_NONE: printf("field:V4L2_FIELD_NONE\n"); break; case V4L2_FIELD_TOP: printf("field:V4L2_FIELD_TOP\n"); break; case V4L2_FIELD_BOTTOM: printf("field:V4L2_FIELD_BOTTOM\n"); break; case V4L2_FIELD_INTERLACED: printf("field:V4L2_FIELD_INTERLACED\n"); break; case V4L2_FIELD_SEQ_TB: printf("field:V4L2_FIELD_SEQ_TB\n"); break; case V4L2_FIELD_SEQ_BT: printf("field:V4L2_FIELD_SEQ_BT\n"); break; case V4L2_FIELD_ALTERNATE: printf("field:V4L2_FIELD_ALTERNATE\n"); break; case V4L2_FIELD_INTERLACED_TB: printf("field:V4L2_FIELD_INT