title: CvCaptureFromAVI problems - OpenCV Android
body: <p>I need to capture frame by frame from a video stored in my sd card of the Android device (in this case my emulator). I am using Android and OpenCV through NDK. I pushed manually the file "SinglePerson.avi" inside the sdcard through file explorer of DDBS (eclipse) and I used the code below to read the file:</p>
  
  <pre><code>    JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial4_Sample4Mixed_VideoProcessing(JNIEnv*, jobject)
  {
      LOGI("INSIDE VideoProcessing ");
  
      CvCapture* capture = cvCaptureFromAVI("/mnt/sdcard/SinglePerson.avi");
  
      IplImage* img = 0;
  
      if(!cvGrabFrame(capture)){              // capture a frame
          LOGI("Inside the if");
          printf("Could not grab a frame\n\7");
          exit(0);
      }
      img=cvRetrieveFrame(capture);// retrieve the captured frame
      cvReleaseCapture(&amp;capture);
  
  }
  </code></pre>
  
  <p>The problem is that cvGrabFrame(capture) results always false.
  Any suggestion to correctly open the video and grab the frames?
  Thanks in advance</p>