基于video4linux2的双usb摄像头图像获取显示

#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 "fbg.h" #include <asm/types.h> #include <linux/videodev2.h> #define CLEAR(x) memset (&(x), 0, sizeof (x)) #define PIC_NUM 100 int width=176, height=144,i,choice,flag; int fd0,fd1,fd2; unsigned char *rgb888_buf = NULL; unsigned char *rgb565_buf = NULL; static unsigned int n_buffers = 0; int byte_size,size; static unsigned long file_length; static char * dev_name1 = "/dev/video0";//摄像头设备名 static char * dev_name2 = "/dev/video1";//摄像头设备名 struct buffer * buffers1 = NULL; struct buffer * buffers2 = NULL; struct buffer { void * start; size_t length; }; //////////////////////////////////////////////////////////////////////////////////////////////////////////// int convert_yuv_to_rgb_pixel(int y, int u, int v) { unsigned int pixel32 = 0; unsigned char *pixel = (unsigned char *)&pixel32; int r, g, b; r = y + (int)((1.370705 * ((float)(v-128)))); g = y - (int)((0.698001 * ((float)(v-128)))) - (int)((0.337633 * ((float)(u-128)))); b = y + (int)((1.732446 * ((float)(u-128)))); if(r > 255) r = 255; if(g > 255) g = 255; if(b > 255) b = 255; if(r < 0) r = 0; if(g < 0) g = 0; if(b < 0) b = 0; pixel[0] = b * 31 / 255; pixel[1] = r * 31 / 255; pixel[2] = g * 63 / 255; return pixel32; } //////////////////////////////////////////////////////////////////////////////////////////////////////////// int convert_yuv_to_rgb_buffer(unsigned char *yuv, unsigned char *rgb, unsigned int width, unsigned int height) { unsigned int in, out = 0; unsigned int pixel_16; unsigned char pixel_24[3]; unsigned int pixel32; int y0, u, y1, v; for(in = 0; in < width * height * 2; in += 4) { pixel_16 = yuv[in + 3] << 24 | yuv[in + 2] << 16 | yuv[in + 1] << 8 | yuv[in + 0]; y0 = (pixel_16 & 0x000000ff); u = (pixel_16 & 0x0000ff00) >> 8; y1 = (pixel_16 & 0x00ff0000) >> 16; v = (pixel_16 & 0xff000000) >> 24; pixel32 = convert_yuv_to_rgb_pixel(y0, u, v); pixel_24[0] = (pixel32 & 0x000000ff); pixel_24[1] = (pixel32 & 0x0000ff00) >> 8; pixel_24[2] = (pixel32 & 0x00ff0000) >> 16; rgb[out++] = pixel_24[0]; rgb[out++] = pixel_24[1]; rgb[out++] = pixel_24[2]; pixel32 = convert_yuv_to_rgb_pixel(y1, u, v); pixel_24[0] = (pixel32 & 0x000000ff); pixel_24[1] = (pixel32 & 0x0000ff00) >> 8; pixel_24[2] = (pixel32 & 0x00ff0000) >> 16; rgb[out++] = pixel_24[0]; rgb[out++] = pixel_24[1]; rgb[out++] = pixel_24[2]; } return 0; } //////////////////////////////////////////////////////////////////////////////////////////////////////////// void convert_rgb888_to_rgb565_buffer(unsigned char *rgb888_buf, unsigned char *rgb565_buf, unsigned int width, unsigned int height,int biasn,int biasm) { int m,n,l; char r,g1,g2,b; for( m = 0; m < height; m++ ) for( n = 0; n < width; n++ ) { r = (rgb888_buf[3*(m*width+n) + 0]); g1 = g2 = (rgb888_buf[3*(m*width+n) + 1]); b = (rgb888_buf[3*(m*width+n) + 2]); l = ( n + biasn ) * (vinfo.bits_per_pixel/8) + ( m + biasm ) * (finfo.line_length); rgb565_buf[l+0]=( (r >> 3) << 3 ) + ( g1 >> 5 ); rgb565_buf[l+1]=( ((g2 << 3) >> 5) << 5 ) + ( b >> 3 ); } } //////////////////////////////////////////////////////////////////////////////////////////////////////////// static int read_frame (void) { struct v4l2_buffer buf1,buf2; if(choice == 1 || choice ==3) { CLEAR (buf1); buf1.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf1.memory = V4L2_MEMORY_MMAP; ioctl (fd1, VIDIOC_DQBUF, &buf1); //出列采集的帧缓冲 assert (buf1.index < n_buffers); convert_yuv_to_rgb_buffer(buffers1[buf1.index].start,rgb888_buf, width,height); convert_rgb888_to_rgb565_buffer(rgb888_buf,rgb565_buf, width,height,32,64); } if(choice == 2 || choice ==3) { CLEAR (buf2); buf2.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf2.memory = V4L2_MEMORY_MMAP; ioctl (fd2, VIDIOC_DQBUF, &buf2); //出列采集的帧缓冲 assert (buf2.index < n_buffers); convert_yuv_to_rgb_buffer(buffers2[buf2.index].start,rgb888_buf, width,height); convert_rgb888_to_rgb565_buffer(rgb888_buf,rgb565_buf, width,height,272,64); } size=write(fd0,rgb565_buf,480*272*2); close (fd0); if((fd0 = open("/dev/fb0", O_RDWR)) < 0){ handle_error("when open framebuffer device"); } ioctl (fd1, VIDIOC_QBUF, &buf1); //再将其入列 ioctl (fd2, VIDIOC_QBUF, &buf2); //再将其入列 //printf("size=%d\n",size); return 1; } //////////////////////////////////////////////////////////////////////////////////////////////////////////// void framebuffer_init(void) { printf("I am framebuffer\n"); if((fd0 = open("/dev/fb0", O_RDWR)) < 0){ handle_error("when open framebuffer device"); } if(ioctl(fd0, FBIOGET_FSCREENINFO, &finfo)){ handle_error("FBIOGET_FSCREENINFO"); } if(ioctl(fd0, FBIOGET_VSCREENINFO, &vinfo)){ handle_error("FBIOGET_VSCREENINFO"); } screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8; printf("screensize=%d\n",screensize); printf("vinfo.xres=%d\n",vinfo.xres); printf("vinfo.yres=%d\n",vinfo.yres); printf("vinfo.bits.per.pixel=%d\n",vinfo.bits_per_pixel); printf("finfo.line_length=%d\n",finfo.line_length); } //////////////////////////////////////////////////////////////////////////////////////////////////////////// void cma1_init(void) { struct v4l2_format fmt; struct v4l2_capability cap; fd1 = open (dev_name1, O_RDWR /* required */ | O_NONBLOCK, 0);//打开设备 ioctl (fd1, VIDIOC_QUERYCAP, &cap);//获取摄像头参数 CLEAR (fmt); fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.width = width; fmt.fmt.pix.height = height; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV; fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; ioctl (fd1, VIDIOC_S_FMT, &fmt); //设置图像格式 file_length = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height; //计算图片大小 printf ("cam1_whidth = %d\n",fmt.fmt.pix.width); printf ("cam1_height = %d\n",fmt.fmt.pix.height); printf ("cam1_picsize = %d\n\n",file_length); } //////////////////////////////////////////////////////////////////////////////////////////////////////////// void cam1_mmap(void) { struct v4l2_requestbuffers req; CLEAR (req); req.count = 4; req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; req.memory = V4L2_MEMORY_MMAP; ioctl (fd1, VIDIOC_REQBUFS, &req); //申请缓冲，count是申请的数量 if (req.count < 2) printf("Insufficient buffer memory\n"); buffers1 = calloc (req.count, sizeof (*buffers1));//内存中建立对应空间 for (n_buffers = 0; n_buffers < req.count; ++n_buffers) { struct v4l2_buffer buf; //驱动中的一帧 CLEAR (buf); buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf.memory = V4L2_MEMORY_MMAP; buf.index = n_buffers; if (-1 == ioctl (fd1, VIDIOC_QUERYBUF, &buf)) //映射用户空间 printf ("VIDIOC_QUERYBUF error\n"); buffers1[n_buffers].length = buf.length; buffers1[n_buffers].start = mmap (NULL,/*通过mmap建立映射关系*/ buf.length,PROT_READ | PROT_WRITE,MAP_SHARED,fd1, buf.m.offset); if (MAP_FAILED == buffers1[n_buffers].start) printf ("mmap failed\n"); } 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 == ioctl (fd1, VIDIOC_QBUF, &buf))//申请到的缓冲进入列队 printf ("VIDIOC_QBUF failed\n"); } } ////