Recherche avancée

Sur d’autres sites (3994)

• A video player based on QtAV with Direct2D / OpenGL rendering

  22 juin 2015, par ashikthomas

  I’m developing a video player in Qt C++ using QtAV. QtAV uses ffmpeg internally. I need to show semi transparent overlays both my watermark logo and subtitles. I’m writing the application for windows. I use OpenAL library. OpenGL and Direct2D are the choice for renderers.

  If I use OpenGL renderer, it works fine in some systems. The overlay works fine. But in some other systems the whole application will be just a black window. Nothing else I can see.

  If I use Direct2D, the overlay wont work. And the renderer is a bit slow. But it works on all systems, without this overlays.

  I have no code to show here because its not the coding issue. Even the examples in QtAV are not working. I need to find a way to show the overlays using Direct2D renderer OR find a solid way to use OpenGL rendering on all systems without fail.

• make fifo pipe in java(windows), write some data into it, let other process read the pipe

  9 novembre 2017, par vs93

  My objective is to create a named pipe(fifo) in windows(java), write some data(coming from camera) into that and invoke ffmpeg command to make mp4 from that data. But I suspect that it is not opening a fifo pipe, rather it is opening a file. How can I make it open a fifo pipe ?
  Here is the code :

  public void run () {
  
  String mp4Folder = "C://Users/user_2/Desktop/streamDestination";            // Where the MP4 is to be kept
  
  VFrame frame = null;
  
  int actualPipeValLen = 0;
  
  FileOutputStream requestStream = null;
  
  long lastProcessedTS = 0;
  
  final String FIFOPATH = "D://FIFO//";
  
  final String PIPE_NAME = FIFOPATH + "myfifo";
  
  final String MKFIFOCOMMAND = "mkfifo -m=rw " + PIPE_NAME;
  
  final String DELFIFOCOMMAND = "rm -r " + PIPE_NAME;
  
  String mp4FileName = mp4Folder + File.separator + "1.mp4";
  
  mp4FileName = mp4FileName.replace("\\", "/");
  
  long firstTimeStamp = 0;
  
  try {
  
      Runtime.getRuntime().exec(MKFIFOCOMMAND);
  
  } catch (IOException e1) {
  
      e1.printStackTrace();
  
  }
  
  if(firstTimeStamp == 0) {
  
      firstTimeStamp = frame.getTimestamp();
  
  }
  
  if((frame.getTimestamp() - firstTimeStamp) > (15 * 1000)) {
  
      if(requestStream != null) {
  
          requestStream.close();
  
          requestStream = null;
  
      }
  
      if(actualPipeValLen > 0) {
  
          String[] ffmpeg = new String[] {"ffmpeg", "-i", PIPE_NAME , "-vcodec", "copy", mp4FileName };
  
          Process ffmpegProcess = Runtime.getRuntime().exec(ffmpeg);
  
          actualPipeValLen = 0;
  
          firstTimeStamp = lastProcessedTS;
  
          Thread.sleep(2 * 1000);
  
          try {
  
              Runtime.getRuntime().exec(DELFIFOCOMMAND);
  
          } catch (IOException e1) {
  
              e1.printStackTrace();
  
          }
  
          System.exit(0);
  
      }
  
  } else {
  
      System.out.println("Writing into pipe : " + actualPipeValLen);
  
      if(requestStream == null) {
  
          requestStream = new  FileOutputStream(PIPE_NAME);
  
      }
  
      requestStream.write(frame.getFrame());
  
      actualPipeValLen += frame.getFrame().length;
  
      lastProcessedTS = frame.getTimestamp();
  
  }

  }

• Overlay a video with rounded corners - FFMPEG React Native (Like Facetime or other Video Chats)

  25 février 2024, par Christopher Gabba

  I'm trying to overlay one video on top of another using FFMPEG, in the exact same format as FaceTime, but the video would have rounded corners. I've tried the commands on other posts but they all generate unexpected results or errors.

  


  Here is the command that overlays the videos decently :

  


  -i main_video.mp4 -i small_overlaid_video_in_lower_left_corner.mp4 -filter_complex \
        "[0:v]scale=iw:ih[main_scaled]; \
        [1:v]scale=iw/2:ih/2:force_original_aspect_ratio=decrease,format=yuva420p[reaction_resized]; \
        [main_scaled][reaction_resized]overlay=x=40:y=H-h-40:format=auto[final]" \
        -map "[final]" -map 1:a? -c:a copy -c:v libx264 -crf 18 -preset ultrafast -t -y output.mp4


  


  The problems this has is that the main videos resolution varies from video to video, so sometimes the overlaid video is super small and sometimes its too big. Three questions :

  


  

  1. How do I make the overlaid video the same size in comparison to the main video every time ?

  


  2. How can I apply rounded corners on the rectangle ?

  


  3. How can I modify it to include both video's audio ?