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• NoClassDefFoundError at FFmpegFrameRecorder

  30 janvier 2015, par Sanjay Rapolu

  I am developing a android application and converting set of images into videos is one of its functionality. whenever I am trying to create an object of FFmpegFrameRecorder, NoClassDefFoundError java lang.ClassNotFoundException org.bytedeco.javacv.FFmpegFraerecorder exception is getting throwed. Here is the code on which I’m working. can anyone please suggest the reason for this error and the solution ?

  package com.example.makevideo;
  
  
  
  import java.io.File;
  
  
  
  import org.bytedeco.javacpp.opencv_core;
  
  import org.bytedeco.javacpp.opencv_core.IplImage;
  
  import org.bytedeco.javacv.FFmpegFrameRecorder;
  
  
  
  import android.app.Activity;
  
  import android.os.Bundle;
  
  import android.os.Environment;
  
  import android.util.Log;
  
  import android.view.View;
  
  import android.widget.Button;
  
  import android.widget.Toast;
  
  import static org.bytedeco.javacpp.opencv_highgui.cvLoadImage;
  
  
  
  
  
  public class MainActivity extends Activity {
  
  
  
          private static final String EXTR_DIR = "Screenshot";
  
  
  
          String path = Environment.getExternalStorageDirectory() + File.separator
  
                          + EXTR_DIR;
  
          Button Record;
  
  
  
          @Override
  
          protected void onCreate(Bundle savedInstanceState) {
  
                  super.onCreate(savedInstanceState);
  
                  setContentView(R.layout.activity_main);
  
  
  
                  System.out.println("Application Runs");
  
  
  
                  Toast.makeText(getApplicationContext(), path, Toast.LENGTH_SHORT)
  
                                  .show();
  
                  ;
  
                  recording();
  
  
  
          }
  
  
  
          private void recording() {
  
                  // TODO Auto-generated method stub
  
  
  
                  Record = (Button) findViewById(R.id.Record);
  
  
  
                  Record.setOnClickListener(new View.OnClickListener() {
  
  
  
                          @Override
  
                          public void onClick(View v) {
  
                                  // TODO Auto-generated method stub
  
                                  System.out.println(path);
  
                                  Toast.makeText(getApplicationContext(), path, Toast.LENGTH_LONG)
  
                                                  .show();
  
                                  Log.d("Record",
  
                                                  "Environment.getExternalStorageDirectory().getPath()  : "
  
                                                                  + path);
  
                                  record();
  
                          }
  
                  });
  
          }
  
  
  
          private void record() {
  
  
  
                  File folder = new File(path);
  
  
  
                  File[] listOfFiles = folder.listFiles();
  
                  opencv_core.IplImage[] iplimage = null;
  
                  if (listOfFiles.length > 0) {
  
  
  
                          System.out.println("in IFFF...");
  
  
  
                          // Toast.makeText(getApplicationContext(), listOfFiles.length,
  
                          // Toast.LENGTH_SHORT).show();
  
                          iplimage = new opencv_core.IplImage[listOfFiles.length];
  
  
  
                          for (int j = 0; j < listOfFiles.length; j++) {
  
  
  
                                  String files = "";
  
  
  
                                  if (listOfFiles[j].isFile()) {
  
                                          files = listOfFiles[j].getName();
  
                                          System.out.println(" j " + j + listOfFiles[j]);
  
                                  }
  
  
  
                                  String[] tokens = files.split("\\.(?=[^\\.]+$)");
  
                                  String name = tokens[0];
  
  
  
                                  Toast.makeText(getApplicationContext(),
  
                                                  "size=" + listOfFiles.length, Toast.LENGTH_SHORT)
  
                                                  .show();
  
  
  
                                  iplimage[j] = cvLoadImage(path + File.separator + name + ".jpg");
  
  
  
                          }
  
  
  
                  }
  
  
  
                  FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(path
  
                                  + File.separator + "OUTPUT" + System.currentTimeMillis()
  
                                  + ".mp4", 200, 150);
  
  
  
                  try {
  
                          recorder.setVideoCodec(13); // CODEC_ID_MPEG4 //CODEC_ID_MPEG1VIDEO
  
                          // //http://stackoverflow.com/questions/14125758/javacv-ffmpegframerecorder-properties-explanation-needed
  
  
  
                          recorder.setFrameRate(1); // This is the frame rate for video. If
  
                                                                                  // you really want to have good video
  
                                                                                  // quality you need to provide large set
  
                                                                                  // of images.
  
                          recorder.setPixelFormat(0); // PIX_FMT_YUV420P
  
  
  
                          recorder.start();
  
  
  
                          for (int i = 0; i < iplimage.length; i++) {
  
  
  
                                  recorder.record(iplimage[i]);
  
  
  
                          }
  
                          
  
                          recorder.stop();
  
                          Toast.makeText(MainActivity.this, "Record Completed",
  
                                          Toast.LENGTH_SHORT).show();
  
  
  
                  } catch (Exception e) {
  
                          e.printStackTrace();
  
                  }
  
          }
  
  
  
  }

• Converting cv::Mat image from BGR to YUV using ffmpeg

  10 mars 2016, par bot1131357

  I am trying to convert BGR image into YUV420P, but when I try to view each of the YUV planes separately, this is what I see.

  Shouldn’t cv::Mat::data and AVFrame::data[0] be packed in the same way ? I should be able to do a direct memcpy. Am I missing something ?

  Any ideas ?

  Mat frame;
  
  VideoCapture cap;
  
  if(!cap.open(0)){
  
      return 0;
  
  }
  
  
  
  // capture a frame
  
  cap >> frame;
  
  if( frame.empty() ) return 0;
  
  
  
  cv::Size s = frame.size();
  
  int height = s.height;
  
  int width = s.width;
  
  
  
  // Creating two frames for conversion
  
  AVFrame *pFrameYUV =av_frame_alloc();
  
  AVFrame *pFrameBGR =av_frame_alloc();
  
  
  
  // Determine required buffer size and allocate buffer for YUV frame 
  
  int numBytesYUV=av_image_get_buffer_size(AV_PIX_FMT_YUV420P, width,
  
                  height,1);          
  
  
  
  // Assign image buffers
  
  avpicture_fill((AVPicture *)pFrameBGR, frame.data,      AV_PIX_FMT_BGR24,
  
      width, height);
  
  
  
  uint8_t* bufferYUV=(uint8_t *)av_malloc(numBytesYUV*sizeof(uint8_t));
  
  avpicture_fill((AVPicture *)pFrameYUV, bufferYUV, AV_PIX_FMT_YUV420P,
  
          width, height);
  
  
  
  // Initialise Software scaling context
  
  struct SwsContext *sws_ctx = sws_getContext(width,
  
      height,
  
      AV_PIX_FMT_BGR24,
  
      width,
  
      height,
  
      AV_PIX_FMT_YUV420P,
  
      SWS_BILINEAR,
  
      NULL,
  
      NULL,
  
      NULL
  
      );
  
  
  
  // Convert the image from its BGR to YUV
  
  sws_scale(sws_ctx, (uint8_t const * const *)pFrameBGR->data,
  
        pFrameYUV->linesize, 0, height,
  
        pFrameYUV->data, pFrameYUV->linesize);
  
  
  
  
  
  
  
  // Trying to see the different planes of YUV
  
  Mat MY = Mat(height, width, CV_8UC1);
  
  memcpy(MY.data,pFrameYUV->data[0], height*width);
  
    imshow("Test1", MY); // fail
  
  Mat MU = Mat(height/2, width/2, CV_8UC1);
  
  memcpy(MU.data,pFrameYUV->data[1], height*width/4);
  
    imshow("Test2", MU); // fail
  
  Mat MV = Mat(height/2, width/2, CV_8UC1);
  
  memcpy(MV.data,pFrameYUV->data[2], height*width/4);
  
    imshow("Test3", MV); // fail  
  
  
  
  waitKey(0); // Wait for a keystroke in the window

• How to Save an Image (Current Frame) from an RTSP, using FFMPEG ?

  4 mars 2023, par spaceman

  I recently purchased a Security Camera,
  
and it provides an RTSP URL withwhich you can view the video.

  


  So If I run the command VLC rtsp://<ip>/etc</ip> for example,
  
then I am successfully able to watch the stream from the camera.

  


  My question is :
  
Does FFMPEG provide some command line operation for Saving one Image from an RTSP Stream to disk ?

  


  That way I can run this command, and have a .PNG or .JPG file created on disk.