C、Zbar库，两个摄像头同时扫描

Question

如何使用两个网络摄像头使用 Zbar 库扫描二维码？

  void *scanning_f(void *ptr)
  {
    const char *first_cam = "/dev/video0";
    const char *second_cam = "/dev/video2";

    zbar_processor_t *proc = zbar_processor_create(1);
    zbar_processor_set_config(proc, 0, ZBAR_CFG_ENABLE, 1);
    zbar_processor_request_size(proc, 1024,  860);
    zbar_processor_init(proc, first_cam, 0);
    zbar_processor_set_data_handler(proc, handling, NULL);
    zbar_processor_set_visible(proc, 0);
    zbar_processor_set_active(proc, 1);
    
    zbar_processor_t *proc2 = zbar_processor_create(1);
    zbar_processor_set_config(proc2, 0, ZBAR_CFG_ENABLE, 1);
    zbar_processor_request_size(proc2, 1024,  860);
    zbar_processor_init(proc2, second_cam, 0);
    zbar_processor_set_data_handler(proc2, handling, NULL);
    zbar_processor_set_visible(proc2, 0);
    zbar_processor_set_active(proc2, 1);
    
    while(1)
    {
        zbar_process_one(proc, 1000);
        zbar_process_one(proc2, 1000);
    }
}

这个功能

zbar_processor_set_active(proc, 1);

似乎将读数锁定到第一个激活的相机。即使两者都工作（LED 亮起）。

Answer 1

• 单独的线程：每个相机在自己的线程中运行以避免
• 初始化和清理：处理器被正确初始化和销毁。
• 处理函数：确保定义处理方式来处理二维码数据。

这确保两个摄像头可以同时扫描二维码：

#include <pthread.h>
#include <zbar.h>

void handling(zbar_image_t *image);  // Define your handling function

typedef struct {
    const char *cam_device;
} camera_info;

void *scanning_f(void *ptr) {
    camera_info *cam_info = (camera_info *)ptr;
    const char *cam_device = cam_info->cam_device;

    zbar_processor_t *proc = zbar_processor_create(1);
    zbar_processor_set_config(proc, 0, ZBAR_CFG_ENABLE, 1);
    zbar_processor_request_size(proc, 1024,  860);
    zbar_processor_init(proc, cam_device, 0);
    zbar_processor_set_data_handler(proc, handling, NULL);
    zbar_processor_set_visible(proc, 0);
    zbar_processor_set_active(proc, 1);

    while (1) {
        zbar_process_one(proc, 1000);
    }

    zbar_processor_destroy(proc);
    pthread_exit(NULL);
}

int main() {
    pthread_t thread1, thread2;
    camera_info cam1 = {"/dev/video0"};
    camera_info cam2 = {"/dev/video2"};

    pthread_create(&thread1, NULL, scanning_f, &cam1);
    pthread_create(&thread2, NULL, scanning_f, &cam2);

    pthread_join(thread1, NULL);
    pthread_join(thread2, NULL);

    return 0;
}