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• Apply sound effects on a video file

  31 mars 2013, par talhamalik22

  I am a little miss guided here and it seems i am totally lost. I am developing an android app and its core idea is to develop a video recorder and video player that applies some sound effects on the voice of the people or any sound that it records. Sound effect means that if i make a video of a person who is giving some speech then there should be no effect on video but his/her voice should appear like voice in talking tom cat app. I hope you understand the idea. Similar app is Helium Booth you can check it here. I am trying to use libraries like libSonic, libpd and tried to use XUGGLE too.
  Read somewhere that Xuggle is not really developed for mobile devices so left it. Now what i want is that it should apply this effect on voice on the run time i.e while recording the pitch of the sound should be alterd and saved immediately. And what i am getting with these libraries is that i can apply sound effect after video is recorded. So it means i need to rip the audio from the video and then apply the change in pitch and frequency and again concatenate this audio file with the old video file. And i have no idea how to do it.
  Please show me the right approach and tools if possible.

  Regards

• Using ffmpeg, the function av_find_input_format("avfoundation") return null

  28 avril 2019, par guojing

  I run this code in iPad mini 4 (Model A1538), iOS 11.2.6

  Try to record audio by FFmpeg.

  av_register_all();
  
  avcodec_register_all();
  
  avdevice_register_all();
  
  
  
  AVFormatContext *pFormatCtx = avformat_alloc_context();
  
  AVDictionary* options = NULL;
  
  av_dict_set(&options,"list_devices","true",0);
  
  AVInputFormat *iformat = av_find_input_format("avfoundation");
  
  printf("==AVFoundation Device Info===\n");
  
  avformat_open_input(&pFormatCtx,"",iformat,&options);
  
  printf("=============================\n");
  
  
  
  if(avformat_open_input(&pFormatCtx,"0",iformat,NULL)!=0){
  
      printf("Couldn't open input stream.\n");
  
      return;
  
  }

  pFormatCtx = NULL, and iformat = NULL.

  Why should this happen, did I missed anything to set ?

• RTSP Streaming on Jetson Xavier NX, Ubuntu 20.04 [closed]

  12 décembre 2023, par Jan

  i am working on a project, where i want to create a rtsp live server from a USB Camera.
To do that i downloaded the mediamtx rtsp server.

  


  Then i am pushing the stream from the camera to the rtsp server, and display it using ffplay, or OpenCV in C++.

  


  This is working, however i get a very low quality, and a delay of up to 1 second.

  


  Is there any way to improve the delay ? If possible i would like to have the same quality and delay as if i read it with gst-launch-1.0.

  


  The command for ffmpeg was

  


  ffmpeg -i /dev/video0 -s 1280x720 -vsync 0 - f rtsp rtsp://localhost:8554/mystream


  


  I also tried to utilize the hardware acceleration with cuda

  


  ffmpeg -i /dev/video0 -s 1280x720 -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -f x11grab -fflags nobuffer -i :0.0+0.0 -preset ultrafast -vcodec libx264 - tune zerolatency -g 1 -omit_video_pes_length 0 - f rtsp rtsp://localhost:8554/mystream


  


  With this I get a better quality, but the delay is still very bad.

  


  Any ideas on how to get a live stream with < 100ms ?&#xA;Did I maybe miss out some additional parameters for ffmpeg that resolve that problem ?

  &#xA;