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• Encryption of OpenCV VideoWriter output

  19 juin 2017, par Aryan

  In an embedded project I was using opencv cv::VideoWriter to store frames as video files, also utilising lossless compression codecs (e.g.Lagarith). Now I have the requirement to encrypt the video files before storing them.

  1. Is it possible to get the encoded output from cv::VideoWriter so that an encryption step can be applied before writing the frame to disk ?

  2. Alternatively, is it possible to make cv::VideoWriter output to a custom output stream ? That way encryption steps can be applied on the stream.

  3. If neither of above is possible then is there an alternative to cv::VideoWriter that I can use to get the video format encoding done ?

  The end requirement is to write encrypted files which, after only a decryption step, become video files compatible with standard video players.

• Trying to merge audio with video using ffmpeg

  9 juillet 2019, par vikram

  I am using ffmpeg for merging audio and video. I download a 4 second long MP3 file trying to merge but not successful. i am also trying to merge silent audio. It works but the video become half of its original length. The following command works for silent audio but cuts the video :

  String mergecmd1[]={"-i",output,"-f", "lavfi" ,"-i", "aevalsrc=0", " - 
  
  shortest", "-y", output};     

  This is the command I have used for MP3 audio but it does not work :

     String cmd1[]={"-i", output ,"- 
  
     i","/storage/emulated/0/FestiveApp/Assets/audio.mp3" ,"-codec", "copy", 
  
     "-shortest", output};
  
  
  
           ffmpeg = FFmpeg.getInstance(Donts_Activity.this);
  
      try {
  
  
  
          ffmpeg.execute(command, new ExecuteBinaryResponseHandler() {
  
  
  
              @Override
  
              public void onStart() {

  // Log.e("ffmpeg","Exaction Start") ;
  }

              @Override
  
              public void onProgress(String message) {}
  
  
  
              @Override
  
              public void onFailure(String message) {
  
                  progressDialog.dismiss();
  
                  Log.e("ok",message);
  
              }
  
  
  
              @Override
  
              public void onSuccess(String message) {
  
                  new Sessionmanager(Donts_Activity.this).SetImageToVideoPath(output);
  
  
  
                  Log.e("ok","success");
  
  
  
  
  
                  progressDialog.dismiss();
  
  
  
                  Intent intent=new Intent(Donts_Activity.this,MediaRecorderRecipe.class);
  
                  startActivity(intent);
  
                  finish();
  
              }
  
  
  
              @Override
  
              public void onFinish() {
  
  
  
              }
  
          });
  
      } catch (FFmpegCommandAlreadyRunningException e) {
  
          Log.e("ffmpeg",e.toString());
  
          progressDialog.dismiss();
  
      }

  My first goal generate video with audio but video length does not be reduce or cut if i am using mp3 or silent ffmpeg audio command

• Creating IContainer with WritableByteChannel.

  18 juillet 2014, par AnilJ

  I am trying to create and open a IContainer object which writes into a WritableByteChannel instead of a file. I am doing this as I want to control and process the data being written to the container. Also I want to avoid the file IO which is slower compared to the in memory buffer handler. I write the following piece of code, and its throwing an exception -

  409  [main] ERROR com.xuggle.xuggler - URL: xuggler:594bed48-b791-45f6-83e0-ea5420ca6df9-com.cona.videoclient.chunkgen.D
  
  ataChunkQueue-5c8edb94; Error: could not find output format (../../../../../../../csrc/com/xuggle/xuggler/Container.cpp:
  
  513)

  The code is as follows :

  package com.video.chunkgen;
  
  
  
  import java.io.IOException;
  
  import java.nio.ByteBuffer;
  
  import java.nio.channels.WritableByteChannel;
  
  import java.util.concurrent.ConcurrentLinkedQueue;
  
  
  
  import com.xuggle.xuggler.IContainer;
  
  import com.xuggle.xuggler.IContainerFormat;
  
  
  
  public class DataChunkQueue implements WritableByteChannel {
  
  
  
      private ConcurrentLinkedQueue<datachunk> mChunkQueue = null;
  
  
  
      // constructor
  
      public DataChunkQueue() {
  
          mChunkQueue = new ConcurrentLinkedQueue<datachunk>();
  
      }
  
  
  
      @Override
  
      public void close() throws IOException {
  
          return;
  
      }
  
  
  
      @Override
  
      public boolean isOpen() {
  
          return true;
  
      }
  
  
  
      @Override
  
      public int write(ByteBuffer buffer) throws IOException {
  
          DataChunk vChunk = new DataChunk(buffer);
  
          mChunkQueue.add(vChunk);
  
  
  
          return 0;
  
      }
  
  
  
  
  
      public int read(ByteBuffer buffer) throws IOException {
  
  
  
          int result = 0;
  
  
  
          buffer = mChunkQueue.poll().GetBuffer();
  
          if (buffer != null ) {
  
              result = 0;
  
          } else {
  
              result = 1;
  
          }
  
  
  
          return result;
  
      }
  
  
  
      public int getSize() {
  
          return mChunkQueue.size();
  
      }
  
  
  
      public static void main(String args[]) {
  
  
  
          DataChunkQueue chunkGen = new DataChunkQueue();
  
  
  
          IContainerFormat format = IContainerFormat.make();
  
          format.setInputFormat("mp4");
  
  
  
          IContainer mContainer = IContainer.make();
  
          int retval = mContainer.open(chunkGen, format);
  
      }
  
  }
  
  </datachunk></datachunk>

  Can you please help me correct this implementation and the resolve this exception ?