Sur d’autres sites (11468)

• The First Problem

  19 janvier 2011, par Multimedia Mike — HTML5

  A few years ago, The Linux Hater made the following poignant observation regarding Linux driver support :

  Drivers are only just the beginning... But for some reason y’all like to focus on the drivers. You know why lusers do that ? Because it just happens to be the problem that people notice first.

  And so it is with the HTML5 video codec debate, re-invigorated in the past week by Google’s announcement of dropping native H.264 support in their own HTML5 video tag implementation. As I read up on the fiery debate, I kept wondering why people are so obsessed with this issue. Then I remembered the Linux Hater’s post and realized that the video codec issue is simply the first problem that most people notice regarding HTML5 video.

  I appreciate that the video codec debate has prompted Niedermayer to post on his blog once more. Otherwise, I’m just munching popcorn on the sidelines, amused and mildly relieved that the various factions are vociferously attacking each other rather than that little project I help with at work.

  Getting back to the "first problem" aspect— there’s so much emphasis on the video codec ; I wonder why no one ever, ever mentions word one about an audio codec. AAC is typically the codec that pairs with H.264 in the MPEG stack. Dark Shikari once mentioned that "AAC’s licensing terms are exponentially more onerous than H.264′s. If Google didn’t want to use H.264, they would sure as hell not want to use AAC." Most people are probably using "H.264" to refer to the entire MPEG/H.264/AAC stack, even if they probably don’t understand what all of those pieces mean.

  Anyway, The Linux Hater’s driver piece continues :

  Once y’all have drivers, the fight will move to the next layer up. And like I said, it’s a lot harder at that layer.

  A few months ago, when I wanted to post the WebM output of my new VP8 encoder and thought it would be a nice touch to deliver it via a video tag, I ignored the video codec problem (just encoded a VP8/WebM file) only to immediately discover a problem at a different layer— specifically, embedding a file using a video tag triggers a full file download when the page is loaded, which is unacceptable from end user and web hosting perspectives. This is a known issue but doesn’t get as much attention, I guess because there are bigger problems to solve first (c.f. video codec issue).

  For other issues, check out the YouTube blog’s HTML5 post or Hulu’s post that also commented on HTML5. Issues such as video streaming flexibility, content protection, fullscreen video, webcam/microphone input, and numerous others are rarely mentioned in the debates. Only "video codec" is of paramount importance.

  But I’m lending too much weight to the cacophony of a largely uninformed internet debate. Realistically, I know there are many talented engineers down in the trenches working to solve at least some of these problems. To tie this in with the Linux driver example, I’m consistently stunned these days regarding how simple it is to get Linux working on a new computer— most commodity consumer hardware really does just work right out of the box. Maybe one day, we’ll wake up and find that HTML5 video has advanced to the point that it solves all of the relevant problems to make it the simple and obvious choice for delivering web video in nearly all situations.

  It won’t be this year.

• 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

  


  


• 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 ?