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• ffmpeg drawtext surrounded by rounded rectangle

  7 juillet 2021, par andykais

  I want to use ffmpeg to recreate the text bubbles that appear in apps like tiktok. I created this example using imagemagick to illustrate what I mean :

  


  

  


  So far with ffmpeg, all I am able to create is text backgrounds with sharp corners :

  


  

  


  This was done with the following command :

  


  ffmpeg -i 'live-wallpaper.mp4' -vf "drawtext=text='Hello World':x=(w-text_w)/2:y=(h-text_h)/2:fontsize=100:fontcolor=black:box=1:boxcolor=white: boxborderw=8:fontfile='fonts/proximanova-semibold.otf'" output.mp4


  


  How can I get the output of ffmpeg to look more similar to the first image ? The text isn't always going to be "Hello World" either, so I need a solution that works for text that is shorter, longer, wraps, etc.

  


• How to synchronize audio and video in FFMPEG/C++

  4 juillet 2016, par rlnunes

  I’m receiving 2 streams (an audio and a video) with timestamps from other PCs in my network.
  I’m able to record the video and the audio to separated files (mp4 and aac) with no problems.
  Now I’m trying to put the 2 streams together into a mp4 file, I’ve created 2 queues, one for audio packets and another for video packets and trying to sync them like this :

  void * muxer(void * param) {
  
      QPair completePacketAudio;
  
      QPair completePacketVideo;
  
      AVPacket pkt;
  
      int vts = 0;
  
      int ats = 0;
  
      while(threadMuxRun) {
  
          contextMutex.lock(); 
  
          if(audioPacketQueue.isEmpty() && videoPacketQueue.isEmpty()) {
  
              contextMutex.unlock();
  
              Sleep(0);
  
              continue;
  
          } else if(audioPacketQueue.isEmpty()) {
  
              completePacketVideo = videoPacketQueue.head();
  
              pkt = videoPacketQueue.dequeue().first;
  
              pkt.pts = vts;
  
              vts++;
  
              std::cout << "video ts:" << pkt.pts << std::endl;
  
              av_packet_rescale_ts(&pkt, video_st.st->time_base, video_st.enc->time_base);            
  
          } else if(videoPacketQueue.isEmpty()) {
  
              completePacketAudio = audioPacketQueue.head();
  
              pkt = audioPacketQueue.dequeue().first;
  
              pkt.pts = ats;
  
              ats++;
  
              std::cout << "audio ts:" << pkt.pts << std::endl;
  
              av_packet_rescale_ts(&pkt, audio_st.st->time_base, audio_st.enc->time_base);
  
          } else {
  
              completePacketAudio = audioPacketQueue.head();
  
              completePacketVideo = videoPacketQueue.head();
  
              if(completePacketVideo.second < completePacketAudio.second) 
  
              {
  
                  pkt = completePacketVideo.first;
  
                  pkt.pts = vts;
  
                  vts++;
  
                  videoPacketQueue.dequeue();
  
                  std::cout << "video ts:" << pkt.pts << std::endl;
  
                  av_packet_rescale_ts(&pkt, video_st.st->time_base, video_st.enc->time_base);
  
              } else {
  
                  audioPacketQueue.dequeue();
  
                  pkt = completePacketAudio.first;
  
                  pkt.pts = ats;
  
                  ats++;
  
                  std::cout << "audio ts:" << pkt.pts << std::endl;
  
                  av_packet_rescale_ts(&pkt, audio_st.st->time_base, audio_st.enc->time_base);
  
              }
  
          }
  
          av_interleaved_write_frame(outputContext, &pkt);
  
          av_free_packet(&pkt);
  
          contextMutex.unlock();
  
  
  
      }
  
  
  
      return NULL;
  
  }

  my videos is about 10% faster than the audio, and the audio timing is correct (it has 2 minutes when I record for 2 minutes, but the video has just 1:48).

  If someone can give a tip, thanks in advance.

• Revision 32453 : on renomme xcache en memoization, puisque c’est de ca qu’il s’agit ...

  29 octobre 2009, par fil@… — Log

  on renomme xcache en memoization, puisque c’est de ca qu’il s’agit  http://fr.wikipedia.org/wiki/Memoization (merci a Thomas Sutton)
  le memo filecache.inc se limite a 16^{4 fichiers, ce qui fait qu’il n’y a plus besoin de garbage collector}