Sur d’autres sites (6802)

• JAVE (Java Audio Video Encoder) library exception only on Linux (CentOS 7)

  13 octobre 2017, par Linu Radu

  I’m using JAVE (Java Audio Video Encoder) library and the developed application is on windows.
  On windows the conversion of an .mp3 file is working fine but when I deployed on linux (CentOS 7) an exception is thrown.

  As I understand JAVE has also a wrapper around an ffmpeg executable.

  Here is my code :

  try {
  
          File source = new File(sourceFile);
  
          File target = new File(targetFile);
  
  
  
          final AudioAttributes audio = new AudioAttributes();
  
          audio.setCodec("libmp3lame");
  
          audio.setBitRate(88000);
  
          audio.setChannels(2);
  
          audio.setSamplingRate(44100);   
  
  
  
          EncodingAttributes attrs = new EncodingAttributes();
  
          attrs.setFormat("mp3");
  
          attrs.setAudioAttributes(audio);
  
  
  
          Encoder encoder = new Encoder();
  
          encoder.encode(source, target, attrs);
  
  } catch (EncoderException ex) {
  
      throw ex;
  
  }

  Exception :

  ...
  
  
  
  Caused by: it.sauronsoftware.jave.EncoderException: Error while opening codec for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height
  
      at it.sauronsoftware.jave.Encoder.encode(Encoder.java:926)
  
      at it.sauronsoftware.jave.Encoder.encode(Encoder.java:713)
  
      at com.hft2.ejb.util.Mp3JaveEncoder.encode(Mp3JaveEncoder.java:36)
  
      ... 206 more

  Update

  Here is the official page : http://www.sauronsoftware.it/projects/jave/

  Full exception log : https://jpst.it/1678l

  Does anyone have any idea ?

• Cannot get MediaStream from Electron app to browser via Openvidu media server

  11 juin 2021, par foxy.bunny

  I'm currently having an issue with openvidu-browser-2.17.0.js

  


  I'm trying to transfer a camera stream from RTSP to an Openvidu media server deployed on cloud and get the stream back on the browser.

  


  The RTSP stream was converted into an HLS stream using FFmpeg and played using hls.js. It was captured in an video tag in HTML and I used the HTMLMediaElement.captureStream().getVideoTrack() to generate MediaStreamTrack and passed it into the videoSource property in initPublisher. This publisher part was wrapped in electron. Then, the stream was connected to our cloud Openvidu server deployed on-premises exactly like in the Docs (https://docs.openvidu.io/en/2.18.0/deployment/deploying-on-premises/). The subscriber part is a simple HTML page displayed on the browser to get the stream from the cloud server. The subscriber is responsible for creating session and generating stream from the media server when streamCreated event occurs.

  


  The whole workflow worked nicely when we tested it with our webcam, however, when we use MediaStreamTrack of our stream video instead of webcam, the subscriber part only showed the blank video.

  


  My question is :

  


  1 : Is it possible to stream an MediaStream to Openvidu media server like that ?

  


  2 : If yes, then what am I doing wrong here ?

  


  Describe the bug

  


  Cannot get MediaStream from Electron app to browser via Openvidu media server.

  


  Expected behavior

  


  Receive the stream from the Electron app to browser via Openvidu media server.

  


  Wrong current behavior

  


  Only get blank video

  


  Client device info

  


  

  • Chrome Version 91.0.4472.77 (Official Build) (64-bit) on Windows 10 Version 10.0.19042 Build 19042

  


  


• Right way to use vmaf with ffmpeg

  14 juin, par dravit

  I am trying to calculate the VMAF score of a processed video wrt the original file.

  


  Command I have used :

  


  ffmpeg -y -loglevel info -stats -i original.mp4 -i processed.mp4 -lavfi "[0]null[refdeint];[refdeint]scale=1920:1080:flags=neighbor[ref];[1]setpts=PTS+0.0/TB[b];[b]scale=1920:1080:flags=neighbor[c];[c][ref]libvmaf=log_fmt=json:phone_model=1:model_path={model_path_here}/vmaf_v0.6.1.json:n_subsample=1:log_path=log.json" -f null -


  


  Now as per the official documentation of vmaf with ffmpeg found here, it says source/reference file followed by the encoded/distorted/processed file.

  


  But almost all of the blogs I came across, they are using the other way round order of the args, i.e. processed file followed by the original file.

  


  Few examples :

  


  


  1. https://medium.com/@eyevinntechnology/keep-an-eye-on-the-video-quality-b9bcb58dd5a1 : search for "Using VMAF within FFMPEG" in it.

     


  


  2. https://websites.fraunhofer.de/video-dev/calculating-vmaf-and-psnr-with-ffmpeg/ : search for "Metric Calculation with FFmpeg" in it.

     


  


  


  EDIT

  


  NOTE : Changing the order does change the VMAF score.