cam_test.rar_210_cam总线_linux cam

/* * v4l2.c * * Created on: Aug 8, 2011 * Author: gavin */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include <getopt.h> #include <fcntl.h> #include <unistd.h> #include <errno.h> #include <malloc.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/time.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <asm/types.h> #include <linux/videodev2.h> #include <jpeglib.h> #include <linux/fb.h> #include "v4l2.h" #include "shm.h" struct buffer { void * start; size_t length; }; int fd = -1; struct buffer * buffers = NULL; static unsigned int n_buffers = 0; // global settings static unsigned int width = 640; static unsigned int height = 480; static unsigned char jpegQuality = 70; static char* deviceName = "/dev/video0"; static int fb_bpp; static int cam_fp = -1; static int fb_fp = -1; static char *fb_addr = NULL; static int shm_fd; void deviceOpen(void) { struct stat st; // stat file if (-1 == stat(deviceName, &st)) { fprintf(stderr, "Cannot identify '%s': %d, %s\n", deviceName, errno, strerror (errno)); exit(EXIT_FAILURE); } // check if its device if (!S_ISCHR (st.st_mode)) { fprintf(stderr, "%s is no device\n", deviceName); exit(EXIT_FAILURE); } // open device fd = open(deviceName, O_RDWR /* required */ | O_NONBLOCK, 0); // check if opening was successfull if (-1 == fd) { fprintf(stderr, "Cannot open '%s': %d, %s\n", deviceName, errno, strerror (errno)); exit(EXIT_FAILURE); } shm_fd = create_shm(); } /** initialize device */ void deviceInit(void) { struct v4l2_capability cap; struct v4l2_cropcap cropcap; struct v4l2_crop crop; struct v4l2_format fmt; unsigned int min; if (-1 == xioctl(fd, VIDIOC_QUERYCAP, &cap)) { if (EINVAL == errno) { fprintf(stderr, "%s is no V4L2 device\n",deviceName); exit(EXIT_FAILURE); } else { errno_exit("VIDIOC_QUERYCAP"); } } if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) { fprintf(stderr, "%s is no video capture device\n",deviceName); exit(EXIT_FAILURE); } if (!(cap.capabilities & V4L2_CAP_STREAMING)) { fprintf(stderr, "%s does not support streaming i/o\n",deviceName); exit(EXIT_FAILURE); } /* Select video input, video standard and tune here. */ CLEAR(cropcap); cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; if (0 == xioctl(fd, VIDIOC_CROPCAP, &cropcap)) { crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; crop.c = cropcap.defrect; /* reset to default */ if (-1 == xioctl(fd, VIDIOC_S_CROP, &crop)) { switch (errno) { case EINVAL: /* Cropping not supported. */ break; default: /* Errors ignored. */ break; } } } else { /* Errors ignored. */ } CLEAR (fmt); // v4l2_format fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.width = 800; fmt.fmt.pix.height = 480; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB32; // fmt.fmt.pix.field = V4L2_FIELD_ANY; if (-1 == xioctl(fd, VIDIOC_S_FMT, &fmt)) errno_exit("VIDIOC_S_FMT"); /* Note VIDIOC_S_FMT may change width and height. */ if (width != fmt.fmt.pix.width) { width = fmt.fmt.pix.width; fprintf(stderr,"Image width set to %i by device %s.\n",width,deviceName); } if (height != fmt.fmt.pix.height) { height = fmt.fmt.pix.height; fprintf(stderr,"Image height set to %i by device %s.\n",height,deviceName); } /* Buggy driver paranoia. */ min = fmt.fmt.pix.width * 2; if (fmt.fmt.pix.bytesperline < min) fmt.fmt.pix.bytesperline = min; min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height; if (fmt.fmt.pix.sizeimage < min) fmt.fmt.pix.sizeimage = min; mmapInit(); } void mmapInit(void) { struct v4l2_requestbuffers req; CLEAR (req); req.count = 4; req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; req.memory = V4L2_MEMORY_MMAP; if (-1 == xioctl(fd, VIDIOC_REQBUFS, &req)) { if (EINVAL == errno) { fprintf(stderr, "%s does not support memory mapping\n", deviceName); exit(EXIT_FAILURE); } else { errno_exit("VIDIOC_REQBUFS"); } } if (req.count < 2) { fprintf(stderr, "Insufficient buffer memory on %s\n", deviceName); exit(EXIT_FAILURE); } buffers = calloc(req.count, sizeof(*buffers)); if (!buffers) { fprintf(stderr, "Out of memory\n"); exit(EXIT_FAILURE); } for (n_buffers = 0; n_buffers < req.count; ++n_buffers) { struct v4l2_buffer buf; CLEAR (buf); buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf.memory = V4L2_MEMORY_MMAP; buf.index = n_buffers; if (-1 == xioctl(fd, VIDIOC_QUERYBUF, &buf)) errno_exit("VIDIOC_QUERYBUF"); buffers[n_buffers].length = buf.length; buffers[n_buffers].start = mmap (NULL /* start anywhere */, buf.length, PROT_READ | PROT_WRITE /* required */, MAP_SHARED /* recommended */, fd, buf.m.offset); if (MAP_FAILED == buffers[n_buffers].start) errno_exit("mmap"); } } void captureStart(void) { unsigned int i; enum v4l2_buf_type type; for (i = 0; i < n_buffers; ++i) { struct v4l2_buffer buf; CLEAR (buf); buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf.memory = V4L2_MEMORY_MMAP; buf.index = i; if (-1 == xioctl(fd, VIDIOC_QBUF, &buf)) errno_exit("VIDIOC_QBUF"); } type = V4L2_BUF_TYPE_VIDEO_CAPTURE; if (-1 == xioctl(fd, VIDIOC_STREAMON, &type)) errno_exit("VIDIOC_STREAMON"); } void mainLoop(void) { unsigned int count; count = 1; while (count-- > 0) { for (;;) { fd_set fds; struct timeval tv; int r; FD_ZERO(&fds); FD_SET(fd, &fds); /* Timeout. */ tv.tv_sec = 2; tv.tv_usec = 0; r = select(fd + 1, &fds, NULL, NULL, &tv); if (-1 == r) { if (EINTR == errno) continue; errno_exit("select"); } if (0 == r) { fprintf (stderr, "select timeout\n"); exit(EXIT_FAILURE); } if (frameRead()) break; } } } unsigned char* frameRead(void) { struct v4l2_buffer buf; CLEAR (buf); buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf.memory = V4L2_MEMORY_MMAP; if (-1 == xioctl(fd, VIDIOC_DQBUF, &buf)) { switch (errno) { case EAGAIN: return 0; case EIO: default: errno_exit("VIDIOC_DQBUF"); } } assert (buf.index < n_buffers); imageProcess(buffers[buf.index].start); if (-1 == xioctl(fd, VIDIOC_QBUF, &buf)) errno_exit("VIDIOC_QBUF"); return (unsigned char*)buffers[buf.index].start; } static void jpegWrite(unsigned char* img) { struct jpeg_compress_struct cinfo; struct jpeg_error_mgr jerr; JSAMPROW row_pointer[1]; FILE *outfile = fopen( "1.jpg", "wb" ); // try to open file for saving if (!outfile) { errno_exit("jpeg"); } // create jpeg data cinfo.err = jpeg_std_error( &jerr ); jpeg_create_compress(&cinfo); jpeg_stdio_dest(&cinfo, outfile); // set image parameters cinfo.image_width = 800; cinfo.image_height = 480; cinfo.input_components = 3; cinfo.in_color_space = JCS_RGB; // set jpeg compression parameters to default jpeg_set_defaults(&cinfo); // and then adjust quality setting jpeg_set_quality(&cinfo, jpegQuality, TRUE); // start compress jpeg_start_compress(&cinfo, TRUE); // feed data while (cinfo.next_scanline < cinfo.image_height) { // row_pointer[0] = &img[cinfo.next_scanline * cinfo.image_width * cinfo.input_components]; row_pointer[0] = &img[(cinfo.image_height - cinfo.next_scanline - 1) * cinfo.image_width*3]; jpeg_write_scanlines(&cinfo, row_pointer, 1); } // finish compression jpeg_finish_compress(&cinfo); // destroy jpeg data jpeg_destroy_compress(&cinfo); // close output file fclose(outfile); } void imageProcess(const void* p) { char buff[5]; rcv_shm(shm_fd, buff); int