Recherche avancée

Sur d’autres sites (9912)

• How to stream live video from DJI Professional 3 camera ?

  29 avril 2017, par raullalves

  I have to get the live stream video from DJI Phantom 3 camera in my C++ application, in order to do a Computer Vision processing in OpenCV.

  First I tried sending the H264 raw data through an UDP socket, inside this callback :

          mReceivedVideoDataCallBack = new CameraReceivedVideoDataCallback() {
  
  
  
          @Override
  
          public void onResult(byte[] videoBuffer, int size) {
  
              //Here, I call a method from a class I created, that sends the buffer through UDP
  
              if (gravar_trigger) controleVideo.enviarFrame(videoBuffer, size);
  
  
  
              if (mCodecManager != null)  mCodecManager.sendDataToDecoder(videoBuffer, size);
  
  
  
          }
  
  
  
      };

  That communication above works well. However, I haven’t been able to decode that UDP H264 data in my C++ desktop application. I have tested with FFmpeg lib, but couldn’t get to alocate an AVPacketwith my UDP data, in order to decode using avcodec_send_packet and avcodec_receive_frame. I also had problems with AVCodecContext, since my UDP communication wasn’t a stream like RTSP, where it could get information about its source. Therefore, I had to change how I was trying to solve the problem.

  Then, I found libstreaming, in which can be associate to stream the android video camera to a Wowza Server, creating something like a RTSP stream connection, where the data could be obtained in my final C++ application easily using OpenCV videoCapture. However, libstreaming uses its own surfaceView. In other words, I would have to link the libstreaming surfaceView with the DJI Drone’s videoSurface. I’m really new to Android, so don’t have any clue of how to do that.

  To sum up, is that the correct approach ? Someone has a better idea ? Thanks in advance

• ffmpeg install on windows server 2003. for use in rails app

  15 septembre 2011, par sdk

  I have a rails application which uses ffmpeg for thumbnailing/duration/file format conversion of videos.
  Currently my rails app runs in ubuntu - where ffmpeg works great. But due to some client constraints , need to run rails app on windows.
  I tried looking out for some writeups, googling around some forums but could not get a comprehensive list of steps to run ffmpeg on windows.

  Any help/alternatives/links to ge it running would be of great help.

  Thanks in advance.

• Merge individual frame to video file using Opencv

  18 août 2022, par Rohit

  I am trying to stack a individual frame to a video file using Opencv. I want to combine two different code together to make the individual frame.
Following code help me extract the individual frame,

  


  fourcc = cv2.VideoWriter_fourcc(*'mp4v')
out = cv2.VideoWriter('file_data.mp4',fourcc,20 (1920,1080),False)
while True:
    ret, frame=cap.read()
    mask = object_detector.apply(frame)
    _, mask  = cv2.threshold(mask,254,255,cv2.THRESH_BINARY)       
    contours,_ = cv2.findContours(mask, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    res = cv2.bitwise_and(frame,frame,mask=mask)
    for cnt in contours:
        area = cv2.contourArea(cnt)
        if area>1000:   
            #print("Area of contour:", area)
            cv2.drawContours(frame, [cnt], -1, (0,255,0),2)
            cv2.imwrite("file%d.jpg"%count, frame)
            out.write(frame)
    if cv2.waitKey(1) and 0xFF == ord('q'):
        break


  


  I tried storing the individual frame in array, but it didn't work. It doesn't show any error, but pc crash.

  


  


  fps = 20,
,width = 1920
,height = 1080