我正在使用JavaCV从视频抓取帧。

如果视频在绝对路径中，我可以抓住。但是，如果视频使用HTTP，则JavaCV会抛出错误。

    url = new URL("http://www.sample-videos.com/video/mp4/720/SampleVideo.mp4");
    urlConnection = (HttpURLConnection) url.openConnection();
    InputStream inputStream = urlConnection.getInputStream();
    Java2DFrameConverter bimConverter = new Java2DFrameConverter();

    FFmpegFrameGrabber frameGrabber = new FFmpegFrameGrabber(inputStream);

    String output = "C:\\Users\\xxxx\\Downloads\\Test";
    frameGrabber.start();
     Frame frame;  
     double frameRate=frameGrabber.getFrameRate();  
     int imgNum=5;  
     System.out.println("Video has "+frameGrabber.getFrameRate()+" frames and has frame rate of "+frameRate);  
     try {   
       frameGrabber.setframeNumber(1000);
       frame = frameGrabber.grabKeyFrame();  
       BufferedImage bi = bimConverter.convert(frame);  
       String path = output+File.separator+imgNum+".jpg";  
       ImageIO.write(bi,"png",new File(path));
       frameGrabber.stop();   
       frameGrabber.close();
       frameGrabber.flush();                                                                        
     } catch (Exception e) {  
       e.printStackTrace();  
     }