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• Ip camera using ffmpeg drawing on screen

  6 mars 2014, par user3177342

  I'm using ffmpeg 1.2 to take video from ip camera.I make it draw on the screen, so I wonder if there is some event mechanism to to know if it is time to call av_read_frame ?
  If I read frame not so frequent as the camera gives frames i get segmentation fault = on some malloc functions inside ffmpeg routines(video_get_buffer)

  I also get segmentation fault just when drawing on screen.

  In Render function call every 0 miliseconds

  void BasicGLPane::DrawNextFrame()
  
  {
  
  int f=1;
  
  while(av_read_frame(pFormatCtx, &packet)>=0)
  
      {
  
          // Is this a packet from the video stream?
  
          if(packet.stream_index==videoStream)
  
          {
  
  
  
  
  
              // Decode video frame
  
              avcodec_decode_video2(pCodecCtx, pFrame, &FrameFinished,
  
                                    &packet);
  
  
  
              // Did we get a video frame?
  
              if(FrameFinished)
  
              {
  
                  f++;
  
                  this->fram->Clear();
  
                 // if (pFrame->pict_type == AV_PICTURE_TYPE_I) wxMessageBox("I cadr");
  
                  if (pFrame->pict_type != AV_PICTURE_TYPE_I)
  
                  printMVMatrix(f, pFrame, pCodecCtx);
  
                  pFrameRGB->linesize[0]= pCodecCtx->width*3; // in case of rgb4  one plane
  
  
  
                  sws_scale(swsContext, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
  
                  //glGenTextures(1, &VideoTexture);
  
                  if ((*current_Vtex)==VideoTexture) current_Vtex = &VideoTexture2;else current_Vtex = &VideoTexture;
  
                  glBindTexture(GL_TEXTURE_2D, (*current_Vtex));
  
                  glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
  
                  glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  
                  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  
                  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, pCodecCtx->width, pCodecCtx->height, GL_RGB, GL_UNSIGNED_BYTE, pFrameRGB->data[0]);
  
                  //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, pCodecCtx->width, pCodecCtx->height, 0, GL_RGB, GL_UNSIGNED_BYTE, pFrameRGB->data[0]);
  
                  //glDeleteTextures(1, &VideoTexture);
  
                  GLenum err;
  
                  while ((err = glGetError()) != GL_NO_ERROR)
  
                  {
  
                      cerr << "OpenGL error: " << err << endl;
  
                  }
  
                //  av_free(buffer);
  
              }
  
          }
  
  
  
          // Free the packet that was allocated by av_read_frame
  
          av_free_packet(&packet);
  
          if (f>1) break;
  
      }
  
  
  
  //av_free(pFrameRGB);
  
  }

  The picture I get on the screen is strange (green quads and red lines are motion vectors of those quads)

  http://i.stack.imgur.com/9HJ9t.png

• ffmpeg - reduce background audio noise when recording desktop screen with gdigrab

  17 juillet 2020, par Riz

  I have an application that records desktop screen using FFmpeg. Here is the command I use

  


  ffmpeg.exe -threads 4 -rtbufsize 2048m -f dshow -i audio="Microphone (Realtek Audio)"  -f gdigrab -offset_x 1 -offset_y 1 -video_size 768x432 -probesize 4096M -i desktop -pix_fmt yuv420p -c:v libx264 -crf 28 -preset ultrafast -tune zerolatency -movflags +faststart -r 15 recording.mp4


  


  It works fine. But I want to reduce the background noise from the audio. I have found some native filters for this

  


  

  • afftdn

  


  • anlmdn

  


  • arnndn

  


  


  But not sure how to use them while recording screen. Can you please help ?

  


• Can't use ffmpeg 3.2 in Android project

  21 novembre 2016, par world2ashish

  Tried almost everything, spent almost 4-5 days trying and still counting.

  The reason I want to compile recent version of ffmpeg is because https://github.com/WritingMinds/ffmpeg-android-java doesn’t work for video rotation. For this also I tried multiple answers, different versions of answer (transpose=1, transpose=dir=cclock, etc)

  Somewhere it was mentioned that rotate command wont work with previous versions of ffmpeg, so after a lot of trials, I started working on compilation of new ffmpeg. But all the tutorials for ffmpeg belong to earlier versions (of Android NDk, ffmpeg) which wont work with ffmpeg 3.2 and NDK r13b (I also tried with NDK downloaded by studio itself but no luck). In case it worked for you, please help.

  After a lot of frustrating experience I am writing this. Please help with a workflow or a clear direction. Thanks

  Wasnt able to tag ffmpeg3.2 because of reputation.