a.py

import cv2                                                                                                                                                                                                  
import argparse
import time


def scan_available_cameras(max_ports=10):
    """扫描系统中可用的摄像头端口"""
    available_ports = [] 
    
    for i in range(max_ports):
        cap = cv2.VideoCapture(i)
        if not cap.isOpened():
            cap.release()
            continue
            
        # 尝试读取一帧以确认摄像头是否真的可用
        ret, frame = cap.read() 
        if ret:
            available_ports.append(i)
            
        cap.release()
        
    return available_ports
    

def get_camera_info(camera_index):
    """获取摄像头的详细信息，包括分辨率和设备名称"""
    cap = cv2.VideoCapture(camera_index) 
    cap.set(cv2.CAP_PROP_FRAME_WIDTH,1920)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT,1080)
    if not cap.isOpened():
        return {"status": "error", "message": f"无法打开摄像头 {camera_index}"}

    try:
        # 获取基本信息
        width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
        height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
        fps = cap.get(cv2.CAP_PROP_FPS)

        # 尝试获取设备名称（依赖于操作系统和驱动）
        device_name = f"摄像头 {camera_index}"
        try:
            # Linux系统可能通过V4L2获取设备名称
            import subprocess
            result = subprocess.run(
                f"v4l2-ctl -d /dev/video{camera_index} --all | grep 'Name'",
                shell=True,
                capture_output=True,
                text=True
            )
            if result.stdout:
                device_name = result.stdout.strip().split(':')[1].strip()
        except:
            pass

        info = {
            "status": "success",
            "index": camera_index,
            "device_name": device_name,
            "resolution": f"{width}x{height}",
            "fps": fps
        }

    except Exception as e:
        info = {"status": "error", "message": str(e)}

    while True:
        # 读取一帧图像
        ret, frame = cap.read()

        # 检查是否成功读取图像
        if not ret:
            print("无法获取帧")
            break

        # 显示图像
        cv2.imshow("", frame)
        #cv2.imwrite("debug.png", frame)
        # 等待按键事件，超时时间为1毫秒
        key = cv2.waitKey(30)

        # 按ESC键退出循环（ESC键的ASCII码为27）
        if key == 27:
            print("用户请求退出...")
            break

    cap.release()
    return info


def main():
    parser = argparse.ArgumentParser(description='扫描并检测摄像头分辨率')
    parser.add_argument('--scan', action='store_true', help='扫描所有可用摄像头')
    parser.add_argument('--index', type=int, help='指定要检测的摄像头索引')
    args = parser.parse_args()
    if args.scan:
        print("正在扫描系统中可用的摄像头端口...")
        available_cameras = scan_available_cameras()

        if not available_cameras:
            print("未检测到可用的摄像头")
            return
       
        print("\n可用摄像头列表:")
        for i, cam_idx in enumerate(available_cameras):
            info = get_camera_info(cam_idx)
            if info["status"] == "success":
                print(f"{i+1}. 端口: {cam_idx}, 设备: {info['device_name']}, 分辨率: {info['resolution']}")
            else:
                print(f"{i+1}. 端口: {cam_idx} (无法获取详细信息)")
       
        print("\n使用方法:")
        print(f"python {__file__} --index <端口号>  # 检测指定摄像头的详细信息")
   
    elif args.index is not None:
        print(f"正在检测摄像头 {args.index} 的详细信息...")
        info = get_camera_info(args.index)
       
        if info["status"] == "success":
            print("\n摄像头信息:")
            print(f"  端口号: {info['index']}")
            print(f"  设备名称: {info['device_name']}")
            print(f"  分辨率: {info['resolution']}")
            print(f"  帧率: {info['fps']:.2f} FPS")
        else:
            print(f"错误: {info['message']}")
   
    else:
        parser.print_help()

if __name__ == "__main__":
    main()