Python OpenCV调用笔记本摄像头报错及CAP_DSHOW解决方案

江岸

发布时间：2026-10-15| 3人浏览过

原创

本文针对Python使用OpenCV调用笔记本摄像头时出现的视频窗口闪退及mediaType设置失败报错，提供详细排查与解决方法。通过分析错误日志中关于MFVideoFormat_RGB24的提示，指出默认API在部分Windows环境下存在兼容性问题。核心解决方案是在cv.VideoCapture初始化时显式指定cv.CAP_DSHOW参数，从而绕过Media Foundation框架的限制，确保视频流正常读取。

使用OpenCV打开笔记本电脑摄像头报错

近期需要完成一个下位机向上传输图像数据的任务。在调试阶段，我编写了一个客户端程序，用于获取笔记本电脑摄像头的视频数据并发送给服务器，随后由服务器端展示视频画面。然而在实际运行客户端时遇到了报错，导致视频窗口出现闪退现象。

通常情况下，获取摄像头图像数据的代码编写方式如下：

capture = cv.VideoCapture(0)

但在执行上述代码时，系统会抛出如下错误信息：

[ WARN:0] global C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-52oirelq\opencv\modules\videoio\src\cap_msmf.cpp (677) CvCapture_MSMF::initStream Failed to set mediaType (stream 0, (640x480 @ 30) MFVideoFormat_RGB24(codec not found)

经过网络搜索与排查，发现只需对原有代码进行细微调整即可解决该问题。

# 建立图像读取对象
    capture = cv.VideoCapture(0,cv.CAP_DSHOW)  #更改API设置

代码中的参数0代表调用笔记本电脑自带的内置摄像头。如果设备连接了外接摄像头，用户可以根据实际情况选择1、2等对应的设备索引号。

OpenCV打开摄像头报错问题

CvCapture_MSMF::initStream Failed to set mediaType (stream 0, (640x480 @ 30)

cap=cv2.VideoCapture(0,cv2.CAP_DSHOW)

enum VideoCaptureAPIs {
       CAP_ANY          = 0,            //!< Auto detect == 0
       CAP_VFW          = 200,          //!< Video For Windows (obsolete, removed)
       CAP_V4L          = 200,          //!< V4L/V4L2 capturing support
       CAP_V4L2         = CAP_V4L,      //!< Same as CAP_V4L
       CAP_FIREWIRE     = 300,          //!< IEEE 1394 drivers
       CAP_FIREWARE     = CAP_FIREWIRE, //!< Same value as CAP_FIREWIRE
       CAP_IEEE1394     = CAP_FIREWIRE, //!< Same value as CAP_FIREWIRE
       CAP_DC1394       = CAP_FIREWIRE, //!< Same value as CAP_FIREWIRE
       CAP_CMU1394      = CAP_FIREWIRE, //!< Same value as CAP_FIREWIRE
       CAP_QT           = 500,          //!< QuickTime (obsolete, removed)
       CAP_UNICAP       = 600,          //!< Unicap drivers (obsolete, removed)
       CAP_DSHOW        = 700,          //!< DirectShow (via videoInput)
       CAP_PVAPI        = 800,          //!< PvAPI, Prosilica GigE SDK
       CAP_OPENNI       = 900,          //!< OpenNI (for Kinect)
       CAP_OPENNI_ASUS  = 910,          //!< OpenNI (for Asus Xtion)
       CAP_ANDROID      = 1000,         //!< Android - not used
       CAP_XIAPI        = 1100,         //!< XIMEA Camera API
       CAP_AVFOUNDATION = 1200,         //!< AVFoundation framework for iOS (OS X Lion will have the same API)
       CAP_GIGANETIX    = 1300,         //!< Smartek Giganetix GigEVisionSDK
       CAP_MSMF         = 1400,         //!< Microsoft Media Foundation (via videoInput)
       CAP_WINRT        = 1410,         //!< Microsoft Windows Runtime using Media Foundation
       CAP_INTELPERC    = 1500,         //!< RealSense (former Intel Perceptual Computing SDK)
       CAP_REALSENSE    = 1500,         //!< Synonym for CAP_INTELPERC
       CAP_OPENNI2      = 1600,         //!< OpenNI2 (for Kinect)
       CAP_OPENNI2_ASUS = 1610,         //!< OpenNI2 (for Asus Xtion and Occipital Structure sensors)
       CAP_GPHOTO2      = 1700,         //!< gPhoto2 connection
       CAP_GSTREAMER    = 1800,         //!< GStreamer
       CAP_FFMPEG       = 1900,         //!< Open and record video file or stream using the FFMPEG library
       CAP_IMAGES       = 2000,         //!< OpenCV Image Sequence (e.g. img_%02d.jpg)
       CAP_ARAVIS       = 2100,         //!< Aravis SDK
       CAP_OPENCV_MJPEG = 2200,         //!< Built-in OpenCV MotionJPEG codec
       CAP_INTEL_MFX    = 2300,         //!< Intel MediaSDK
       CAP_XINE         = 2400,         //!< XINE engine (Linux)
     };

附上查看可用摄像头索引号的方法：

import cv2
ID = 0
while(1):
    cap = cv2.VideoCapture(ID,cv2.CAP_DSHOW)
    # get a frame
    ret, frame = cap.read()
    if ret == False:
        ID += 1
    else:
        print(ID)
    break

以上为个人调试经验总结，希望能为大家提供有价值的参考，也希望大家多多支持本站。