Linux下采集摄像头的图像再保存为JPG图片存放到本地(YUYV转JPG)

一、环境介绍

操作系统：ubuntu18.04 X64位 和 嵌入式Linux操作(ARM)

二、功能介绍

通过Linux下标准V4L2框架采集摄像头的数据，通过jpeglib库连续编码为JPG格式图片存放到本地。

三、安装jpeglib库

jpeglib下载地址：http://www.ijg.org/

下载之后解压到linux指定目录下，进行接解压、编译。

代码语言：javascript代码运行次数：0运行复制

wbyq@wbyq:~/work_pc$ tar xvf /mnt/hgfs/linux-share-dir/jpegsrc.v9d.tar.gzwbyq@wbyq:~/work_pc$ cd jpeg-9d/wbyq@wbyq:~/work_pc/jpeg-9d$ ./configure wbyq@wbyq:~/work_pc/jpeg-9d$ makewbyq@wbyq:~/work_pc/jpeg-9d$ sudo make install[sudo] wbyq 的密码： make[1]: 进入目录“/home/wbyq/work_pc/jpeg-9d” /bin/mkdir -p '/usr/local/lib' /bin/bash ./libtool   --mode=install /usr/bin/install -c   libjpeg.la '/usr/local/lib'libtool: install: /usr/bin/install -c .libs/libjpeg.so.9.4.0 /usr/local/lib/libjpeg.so.9.4.0libtool: install: (cd /usr/local/lib && { ln -s -f libjpeg.so.9.4.0 libjpeg.so.9 || { rm -f libjpeg.so.9 && ln -s libjpeg.so.9.4.0 libjpeg.so.9; }; })libtool: install: (cd /usr/local/lib && { ln -s -f libjpeg.so.9.4.0 libjpeg.so || { rm -f libjpeg.so && ln -s libjpeg.so.9.4.0 libjpeg.so; }; })libtool: install: /usr/bin/install -c .libs/libjpeg.lai /usr/local/lib/libjpeg.lalibtool: install: /usr/bin/install -c .libs/libjpeg.a /usr/local/lib/libjpeg.alibtool: install: chmod 644 /usr/local/lib/libjpeg.alibtool: install: ranlib /usr/local/lib/libjpeg.alibtool: finish: PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin:/sbin" ldconfig -n /usr/local/lib----------------------------------------------------------------------Libraries have been installed in:   /usr/local/libIf you ever happen to want to link against installed librariesin a given directory, LIBDIR, you must either use libtool, andspecify the full pathname of the library, or use the '-LLIBDIR'flag during linking and do at least one of the following:   - add LIBDIR to the 'LD_LIBRARY_PATH' environment variable     during execution   - add LIBDIR to the 'LD_RUN_PATH' environment variable     during linking   - use the '-Wl,-rpath -Wl,LIBDIR' linker flag   - have your system administrator add LIBDIR to '/etc/ld.so.conf'See any operating system documentation about shared libraries formore information, such as the ld(1) and ld.so(8) manual pages.---------------------------------------------------------------------- /bin/mkdir -p '/usr/local/bin'  /bin/bash ./libtool   --mode=install /usr/bin/install -c cjpeg djpeg jpegtran rdjpgcom wrjpgcom '/usr/local/bin'libtool: install: /usr/bin/install -c .libs/cjpeg /usr/local/bin/cjpeglibtool: install: /usr/bin/install -c .libs/djpeg /usr/local/bin/djpeglibtool: install: /usr/bin/install -c .libs/jpegtran /usr/local/bin/jpegtranlibtool: install: /usr/bin/install -c rdjpgcom /usr/local/bin/rdjpgcomlibtool: install: /usr/bin/install -c wrjpgcom /usr/local/bin/wrjpgcom/bin/bash /home/wbyq/work_pc/jpeg-9d/install-sh -d /usr/local/include/usr/bin/install -c -m 644 jconfig.h /usr/local/include/jconfig.h /bin/mkdir -p '/usr/local/include' /usr/bin/install -c -m 644 jerror.h jmorecfg.h jpeglib.h '/usr/local/include' /bin/mkdir -p '/usr/local/share/man/man1' /usr/bin/install -c -m 644 cjpeg.1 djpeg.1 jpegtran.1 rdjpgcom.1 wrjpgcom.1 '/usr/local/share/man/man1' /bin/mkdir -p '/usr/local/lib/pkgconfig' /usr/bin/install -c -m 644 libjpeg.pc '/usr/local/lib/pkgconfig'make[1]: 离开目录“/home/wbyq/work_pc/jpeg-9d”

默认的安装路径在/usr/local/lib/ 目录下。

如果是编译给嵌入式Linux平台使用可以按照下面方法配置：

代码语言：javascript代码运行次数：0运行复制

./configure --prefix=/usr/local/lib CC=arm-linux-gcc --host=arm-linux --enable-shared --enable-static

四、核心代码

video_app.c : 摄像头采集的主要代码

存了个图

视频图片解析/字幕/剪辑，视频高清保存/图片源图提取

17 查看详情 代码语言：javascript代码运行次数：0运行复制

#include #include #include #include #include #include #include #include #include #include #include "yuv_to_jpeg.h"int image_height;int image_width;unsigned char *image_buffer[4];int uvc_video_fd;/*函数功能: 摄像头设备初始化*/int VideoDeviceInit(char *DEVICE_NAME){/*1. 打开摄像头设备*/uvc_video_fd=open(DEVICE_NAME,O_RDWR);if(uvc_video_fd<0){printf("%s 摄像头设备打开失败!n",DEVICE_NAME);return -1;}else{printf("摄像头打开成功.n");}/*2 设置摄像头的属性*/struct v4l2_format format;/*2.1 查询当前摄像头支持的格式*///当前视频设备支持的视频图像格式struct v4l2_fmtdesc fmt;memset(&fmt,0,sizeof(fmt));fmt.index = 0;fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;printf("当前摄像头支持输出的图像格式如下:n");while(ioctl(uvc_video_fd,VIDIOC_ENUM_FMT,&fmt) == 0){fmt.index ++ ;printf("n",fmt.pixelformat & 0xff,(fmt.pixelformat >> 8)&0xff,(fmt.pixelformat >> 16) & 0xff,(fmt.pixelformat >> 24)&0xff,fmt.description);}/*2.2 设置摄像头输出的宽度高度与颜色格式(V4L2_PIX_FMT_YUYV)*/memset(&format,0,sizeof(struct v4l2_format));format.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*表示视频捕获设备*/format.fmt.pix.width=2000;  /*预设的宽度*/format.fmt.pix.height=2000; /*预设的高度*/format.fmt.pix.pixelformat=V4L2_PIX_FMT_YUYV; /*预设的格式*/format.fmt.pix.field=V4L2_FIELD_ANY; /*系统自动设置: 帧属性*/if(ioctl(uvc_video_fd,VIDIOC_S_FMT,&format)) /*设置摄像头的属性*/{printf("摄像头格式设置失败!n");return -2;}image_width=format.fmt.pix.width;image_height=format.fmt.pix.height;printf("摄像头实际输出的图像尺寸:x=%d,y=%dn",format.fmt.pix.width,format.fmt.pix.height);if(format.fmt.pix.pixelformat==V4L2_PIX_FMT_YUYV){printf("当前摄像头支持YUV格式图像输出!n");}else{printf("当前摄像头不支持YUV格式图像输出!n");return -3;}/*2.3 设置摄像头采集的帧率*/struct v4l2_streamparm streamparm;streamparm.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*表示视频捕获设备*/streamparm.parm.capture.timeperframe.numerator=1;streamparm.parm.capture.timeperframe.denominator=30;printf("设置当前摄像头采集帧率: %d秒%d帧n",streamparm.parm.capture.timeperframe.numerator,streamparm.parm.capture.timeperframe.denominator);if(ioctl(uvc_video_fd,VIDIOC_S_PARM,&streamparm)) /*设置摄像头的帧率*/{printf("设置摄像头采集的帧率失败!n");return -3;}if(ioctl(uvc_video_fd,VIDIOC_S_PARM,&streamparm)) /*获取摄像头的帧率*/{printf("获取摄像头采集的帧率失败!n");return -3;}printf("当前摄像头实际采集帧率: %d秒%d帧n",streamparm.parm.capture.timeperframe.numerator,streamparm.parm.capture.timeperframe.denominator);/*3. 请求缓冲区: 申请摄像头数据采集的缓冲区*/struct v4l2_requestbuffers req_buff;memset(&req_buff,0,sizeof(struct v4l2_requestbuffers));req_buff.count=4; /*预设要申请4个缓冲区*/req_buff.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/req_buff.memory=V4L2_MEMORY_MMAP; /*支持mmap内存映射*/if(ioctl(uvc_video_fd,VIDIOC_REQBUFS,&req_buff)) /*申请缓冲区*/{printf("申请摄像头数据采集的缓冲区失败!n");return -4;}printf("摄像头缓冲区申请的数量: %dn",req_buff.count);/*4. 获取缓冲区的详细信息: 地址,编号*/struct v4l2_buffer buff_info;memset(&buff_info,0,sizeof(struct v4l2_buffer));int i;for(i=0;i<req_buff.count;i++){buff_info.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/buff_info.memory=V4L2_MEMORY_MMAP; /*支持mmap内存映射*/if(ioctl(uvc_video_fd,VIDIOC_QUERYBUF,&buff_info)) /*获取缓冲区的详细信息*/{printf("获取缓冲区的详细信息失败!n");return -5;}/*根据摄像头申请缓冲区信息: 使用mmap函数将内核的地址映射到进程空间*/image_buffer[i]=mmap(NULL,buff_info.length,PROT_READ|PROT_WRITE,MAP_SHARED,uvc_video_fd,buff_info.m.offset); if(image_buffer[i]==NULL){printf("缓冲区映射失败!n");return -6;}}/*5. 将缓冲区放入采集队列*/memset(&buff_info,0,sizeof(struct v4l2_buffer));for(i=0;i<req_buff.count;i++){buff_info.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/buff_info.index=i; /*缓冲区的节点编号*/buff_info.memory=V4L2_MEMORY_MMAP; /*支持mmap内存映射*/if(ioctl(uvc_video_fd,VIDIOC_QBUF,&buff_info)) /*根据节点编号将缓冲区放入队列*/{printf("根据节点编号将缓冲区放入队列失败!n");return -7;}}/*6. 启动摄像头数据采集*/int Type=V4L2_BUF_TYPE_VIDEO_CAPTURE;if(ioctl(uvc_video_fd,VIDIOC_STREAMON,&Type)){printf("启动摄像头数据采集失败!n");return -8;}return 0;}int main(int argc,char **argv){if(argc!=2){printf("./app n");return 0;}int err;char jpg_file_name[100]; /*存放JPG图片名称*/int jpg_cnt=0;FILE *jpg_file;int jpg_size;/*1. 初始化摄像头设备*/err=VideoDeviceInit(argv[1]);printf("VideoDeviceInit=%dn",err);/*2. 循环读取摄像头采集的数据*/struct pollfd fds;fds.fd=uvc_video_fd;fds.events=POLLIN;/*3. 申请存放JPG的数据空间*/unsigned char *jpg_p=malloc(image_height*image_width*3);struct v4l2_buffer video_buffer;while(1){ /*(1)等待摄像头采集数据*/ poll(&fds,1,-1); /*(2)取出队列里采集完毕的缓冲区*/ video_buffer.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/ video_buffer.memory=V4L2_MEMORY_MMAP; ioctl(uvc_video_fd,VIDIOC_DQBUF,&video_buffer);         /*(3)处理图像数据*/     printf("image_buffer[%d]=%Xn",video_buffer.index,image_buffer[video_buffer.index]);     /*YUV数据转JPEG格式*/ jpg_size=yuv_to_jpeg(image_width,image_height,image_height*image_width*3,image_buffer[video_buffer.index],jpg_p,80); sprintf(jpg_file_name,"%d.jpg",jpg_cnt++); printf("图片名称:%s,字节大小:%dn",jpg_file_name,jpg_size);  jpg_file=fopen(jpg_file_name,"wb"); fwrite(jpg_p,1,jpg_size,jpg_file); fclose(jpg_file);  /*(4)将缓冲区再放入队列*/ ioctl(uvc_video_fd,VIDIOC_QBUF,&video_buffer);}return 0;}

yuv_to_jpg.c : YUV格式图片转JPG格式图片核心代码

代码语言：javascript代码运行次数：0运行复制

#include "yuv_to_jpeg.h"#define OUTPUT_BUF_SIZE  4096typedef struct {  struct jpeg_destination_mgr pub; /* public fields */  JOCTET * buffer;    /* start of buffer */  unsigned char *outbuffer;  int outbuffer_size;  unsigned char *outbuffer_cursor;  int *written;} mjpg_destination_mgr;typedef mjpg_destination_mgr *mjpg_dest_ptr;/******************************************************************************函数功能: 初始化输出的目的地******************************************************************************/METHODDEF(void) init_destination(j_compress_ptr cinfo) {  mjpg_dest_ptr dest = (mjpg_dest_ptr) cinfo->dest;  /* Allocate the output buffer --- it will be released when done with image */  dest->buffer = (JOCTET *)(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, OUTPUT_BUF_SIZE * sizeof(JOCTET));  *(dest->written) = 0;  dest->pub.next_output_byte = dest->buffer;  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;}/******************************************************************************函数功能: 当jpeg缓冲区填满时调用******************************************************************************/METHODDEF(boolean) empty_output_buffer(j_compress_ptr cinfo) {  mjpg_dest_ptr dest = (mjpg_dest_ptr) cinfo->dest;  memcpy(dest->outbuffer_cursor, dest->buffer, OUTPUT_BUF_SIZE);  dest->outbuffer_cursor += OUTPUT_BUF_SIZE;  *(dest->written) += OUTPUT_BUF_SIZE;  dest->pub.next_output_byte = dest->buffer;  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;  return TRUE;}/******************************************************************************函数功能:在写入所有数据之后，由jpeg_finish_compress调用。通常需要刷新缓冲区。******************************************************************************/METHODDEF(void) term_destination(j_compress_ptr cinfo) {  mjpg_dest_ptr dest = (mjpg_dest_ptr) cinfo->dest;  size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;  /* Write any data remaining in the buffer */  memcpy(dest->outbuffer_cursor, dest->buffer, datacount);  dest->outbuffer_cursor += datacount;  *(dest->written) += datacount;}/******************************************************************************功能描述：初始化输出流函数参数:j_compress_ptr cinfo  :保存JPG图像压缩信息的结构体地址unsigned char *buffer :存放压缩之后的JPG图片的缓冲区首地址int size              :源图像字节总大小int *written          :存放压缩之后的JPG图像字节大小******************************************************************************/GLOBAL(void) dest_buffer(j_compress_ptr cinfo, unsigned char *buffer, int size, int *written){  mjpg_dest_ptr dest;  if (cinfo->dest == NULL) {    cinfo->dest = (struct jpeg_destination_mgr *)(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof(mjpg_destination_mgr));  }  dest = (mjpg_dest_ptr) cinfo->dest;  dest->pub.init_destination = init_destination;  dest->pub.empty_output_buffer = empty_output_buffer;  dest->pub.term_destination = term_destination;  dest->outbuffer = buffer;  dest->outbuffer_size = size;  dest->outbuffer_cursor = buffer;  dest->written = written;}/************************************************功能描述：将YUV格式的数据转为JPG格式。函数参数:int Width    源图像宽度int Height   源图像高度int size    源图像字节总大小unsigned char *yuv_buffer :存放YUV源图像数据缓冲区的首地址unsigned char *jpg_buffer :存放转换之后的JPG格式数据缓冲区首地址int quality               :jpg图像的压缩质量(值越大质量越好,图片就越清晰,占用的内存也就越大)一般取值范围是: 10 ~ 100 。 填10图片就有些模糊了，一般的JPG图片都是质量都是80。返回值：压缩之后的JPG图像大小**************************************************************/int yuv_to_jpeg(int Width,int Height,int size,unsigned char *yuv_buffer, unsigned char *jpg_buffer, int quality) {  struct jpeg_compress_struct cinfo;  struct jpeg_error_mgr jerr;  JSAMPROW row_pointer[1];  unsigned char *line_buffer, *yuyv;  int z;  static int written;  /*1. 解压之前的初始化*/  line_buffer =(unsigned char *)calloc(Width*3,1);  yuyv=yuv_buffer; //得到图像源数据  cinfo.err = jpeg_std_error (&jerr);  jpeg_create_compress (&cinfo);    /* 原版jpeglib库的标准输出初始化函数,只能填文件指针: jpeg_stdio_dest (&cinfo, file); */  /* 修改之后的标准输出初始化函数,将输出指向内存空间*/  dest_buffer(&cinfo, jpg_buffer, size, &written);  cinfo.image_width = Width;  cinfo.image_height =Height;  cinfo.input_components = 3;  cinfo.in_color_space = JCS_RGB;  jpeg_set_defaults (&cinfo);  jpeg_set_quality (&cinfo, quality, TRUE);  jpeg_start_compress (&cinfo, TRUE);  /*2. YUV转RGB格式*/  z = 0;  while (cinfo.next_scanline < Height)   {    int x;    unsigned char *ptr = line_buffer;    for (x = 0; x < Width; x++) {      int r, g, b;      int y, u, v;      if (!z)        y = yuyv[0] << 8;      else        y = yuyv[2] <> 8;      g = (y - (88 * u) - (183 * v)) >> 8;      b = (y + (454 * u)) >> 8;      *(ptr++) = (r > 255) ? 255 : ((r  255) ? 255 : ((g  255) ? 255 : ((b < 0) ? 0 : b);      if (z++) {        z = 0;        yuyv += 4;      }    }/*3.进行JPG图像压缩(一行一行压缩)*/    row_pointer[0] = line_buffer;    jpeg_write_scanlines(&cinfo, row_pointer, 1);  }      /*4. 释放压缩时占用的内存空间*/  jpeg_finish_compress(&cinfo);  jpeg_destroy_compress(&cinfo);  free (line_buffer);     /*5. 返回压缩之后JPG图片大小*/  return (written);}

yuv_to_jpg.h : YUV转JPG代码的头文件

代码语言：javascript代码运行次数：0运行复制

#ifndef YUC_TO_JPEG_H#define YUC_TO_JPEG_H#include #include #include #include int yuv_to_jpeg(int Width,int Height,int size,unsigned char *yuv_buffer, unsigned char *jpg_buffer, int quality);#endif

Makefile 文件代码：

代码语言：javascript代码运行次数：0运行复制

all:gcc video_app.c yuv_to_jpeg.c -o app -ljpeg

五、编译运行-测试效果

如果运行时提示找不到库，可以先搜索库的路径，将库的路径加入到环境变量里即可：

error while loading shared libraries: libjpeg.so.9: cannot open shared object file: No such file or directory

代码语言：javascript代码运行次数：0运行复制

wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ ./app ./app: error while loading shared libraries: libjpeg.so.9: cannot open shared object file: No such file or directorywbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ sudo find / -name libjpeg.so.9find: ‘/run/user/1000/gvfs’: 权限不够/home/wbyq/work_pc/jpeg-9d/.libs/libjpeg.so.9/usr/local/lib/libjpeg.so.9wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/

编译程序运行步骤如下：

代码语言：javascript代码运行次数：0运行复制

wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ makegcc video_app.c yuv_to_jpeg.c -o app -ljpegvideo_app.c: In function ‘main’:video_app.c:190:33: warning: format ‘%X’ expects argument of type ‘unsigned int’, but argument 3 has type ‘unsigned char *’ [-Wformat=]       printf("image_buffer[%d]=%Xn",video_buffer.index,image_buffer[video_buffer.index]);                                ~^                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                %hhnwbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ ./app ./app: error while loading shared libraries: libjpeg.so.9: cannot open shared object file: No such file or directorywbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ sudo find / -name libjpeg.so.9find: ‘/run/user/1000/gvfs’: 权限不够/home/wbyq/work_pc/jpeg-9d/.libs/libjpeg.so.9/usr/local/lib/libjpeg.so.9wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ ./app ./app wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c/yuv_save_jpg$ ./app /dev/video0 摄像头打开成功.当前摄像头支持输出的图像格式如下:摄像头实际输出的图像尺寸:x=1280,y=960当前摄像头支持YUV格式图像输出!设置当前摄像头采集帧率: 1秒30帧当前摄像头实际采集帧率: 2秒15帧摄像头缓冲区申请的数量: 4VideoDeviceInit=0image_buffer[0]=4C129000图片名称:0.jpg,字节大小:135722image_buffer[1]=4BED1000图片名称:1.jpg,字节大小:135722image_buffer[2]=4BC79000图片名称:2.jpg,字节大小:135722image_buffer[3]=4BA21000图片名称:3.jpg,字节大小:135722image_buffer[0]=4C129000图片名称:4.jpg,字节大小:132494image_buffer[1]=4BED1000图片名称:5.jpg,字节大小:132494image_buffer[2]=4BC79000图片名称:6.jpg,字节大小:132494image_buffer[3]=4BA21000图片名称:7.jpg,字节大小:132494image_buffer[0]=4C129000图片名称:8.jpg,字节大小:126119image_buffer[1]=4BED1000图片名称:9.jpg,字节大小:126119image_buffer[2]=4BC79000图片名称:10.jpg,字节大小:126119image_buffer[3]=4BA21000图片名称:11.jpg,字节大小:126119

程序停止，可以按下Ctrl+C。

下面图片是采集的效果。

以上就是Linux下采集摄像头的图像再保存为JPG图片存放到本地(YUYV转JPG)的详细内容，更多请关注创想鸟其它相关文章！