Recherche avancée

Sur d’autres sites (14233)

• Android Camera App Performance Increases [closed]

  5 novembre 2012, par Spentak

  I am writing a video recording app but am finding it quite impossible to match the frames per second that are on the native Android device video camera app (on Samsung Galaxy sIII). On the native app I can record at 1920x1080 with effects on at an amazing FPS (not sure exactly what it is but it looks like 25+ fps).

  In my app on the sIII my video recording is incredibly unstable and choppy even at 640x480. My FPS drops to 7 when recording at 640x480. When I add effects the FPS drops to 3-5.

  Can someone help me figure out how to get an FPS that is equal to the native Android camera app (specifically on the sIII) ?

  At this point I'm not sure where to optimize.

  And for reference, I am just doing the standard video recording stuff as in :
  How can I capture a video recording on Android ?

  Thanks !

• OpenCV Multi-camera handling issue

  19 janvier 2013, par user1797582

  1) I get this errors while handling two logitech c310 cameras with OpenCV(updated Kubuntu Linux)

  VIDIOC_STREAMON : No space left on device

  Whole error log is as below

  **IDIOC_QUERYMENU: Invalid argument
  
  VIDIOC_QUERYMENU: Invalid argument**
  
  VIDIOC_QUERYMENU: Invalid argument
  
  VIDIOC_QUERYMENU: Invalid argument
  
  VIDIOC_QUERYMENU: Invalid argument
  
  VIDIOC_QUERYMENU: Invalid argument
  
  VIDIOC_QUERYMENU: Invalid argument
  
  **libv4l2: error turning on stream: No space left on device**
  
  **VIDIOC_STREAMON: No space left on device**
  
  OpenCV Error: Bad flag (parameter or structure field) (Unrecognized or unsupported array type) in cvGetMat, file /home/rjdp/Computer_Vision/0_Installers/OpenCV-2.4.2/modules/core/src/array.cpp, line 2482
  
  terminate called after throwing an instance of 'cv::Exception'
  
    what():  /home/rjdp/Computer_Vision/0_Installers/OpenCV-2.4.2/modules/core/src/array.cpp:2482: error: (-206) Unrecognized or unsupported array type in function cvGetMat

  2) It happens only when Handling two cameras, Even at default low res 640x480. I still tried to lower resolution in code to 320x240 which also did not work.

  3) I searched in lot of other posts here & on other sites. Which told me there is not enough USB cam bandwidth available. So I tried to plug one cam in front USB & one in the back side which also failed :(

  My Question is :

  Is it possible to solve this issue of bandwith/memory & run two or
  more cameras together on opencv 2.4.2 ?? OpenCV uses ffmpeg to handle I/O so can i tell my camera hardware with some ffmpeg command to take input stream with compressed MPEG mode instead of bandwidth consuming normal mode.

  CODE IS AS BELOW :

  #include "opencv2/opencv.hpp"
  
  #include 
  
  using namespace cv;
  
  
  
  int main(int, char**)
  
  {
  
      VideoCapture cap01(0); // open the default camera
  
      cap01.set(CV_CAP_PROP_FRAME_WIDTH,320);
  
      cap01.set(CV_CAP_PROP_FRAME_HEIGHT,240);
  
      //sleep(1);
  
      if(!cap01.isOpened())  // check if we succeeded
  
          return -1;
  
      namedWindow("Camera01",1);
  
  
  
      VideoCapture cap02(1); // open the default camera
  
      cap02.set(CV_CAP_PROP_FRAME_WIDTH,320);
  
      cap02.set(CV_CAP_PROP_FRAME_HEIGHT,240);
  
     if(!cap02.isOpened())  // check if we succeeded
  
          return -1;
  
      namedWindow("Camera02",1);
  
  
  
      for(;;)
  
      {
  
          Mat frame, frame_1;
  
          //Mat frame02;
  
          cap02 >> frame;
  
          imshow("Camera01", frame);
  
          if(waitKey(30) >= 0) break;
  
          Mat frame_1;
  
          cap02 >> frame_1; 
  
          imshow("Camera02", frame_1);
  
          if(waitKey(30) >= 0) break;
  
      }
  
  
  
      return 0;
  
  }

• How to connect DSLR Camera with Android phone using OTG Cable

  16 juillet 2014, par Nitesh Kr Sharma

  I want to connect DSLR camera with Android phone using OTG cable please Help Help and then I want to show live video in Android device screen.