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• Call FFmpeg via JavaCPP：Caused by : java.lang.NoClassDefFoundError : Could not initialize class org.bytedeco.javacpp.avformat$AVFormatContext

  8 décembre 2017, par Xuan

  In CentOS, use javacpp call FFmpeg to do video cropping a frame, in my own development machine using this code is no problem, but in centos6 reported NoClassDefFound : Could not initialize class org.bytedeco.javacpp.avutil

  Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.bytedeco.javacpp.avformat$AVFormatContext
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:383) ~[javacv-1.0.jar:1.0]
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:377) ~[javacv-1.0.jar:1.0]
  
      at cn.xxtui.support.upload.BasicUpload.convertImage(BasicUpload.java:211) ~[classes/:?]
  
      at cn.xxtui.support.upload.BasicUpload.upload(BasicUpload.java:197) ~[classes/:?]
  
      at cn.com.ql.wiseBeijing.upload.UploadImage.upload(UploadImage.java:144) ~[classes/:?]
  
      at cn.com.ql.wiseBeijing.upload.UploadImage.imageCategory(UploadImage.java:51) ~[classes/:?]
  
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_25]
  
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_25]
  
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_25]
  
      at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_25]
  
      at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:180) ~[cxf-core-3.1.12.jar:3.1.12]
  
      at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96) ~[cxf-core-3.1.12.jar:3.1.12]
  
      ... 37 more

  This is my pom configuration：

  <dependency>
  
      <groupid>org.bytedeco</groupid>
  
      <artifactid>javacv</artifactid>
  
      <version>1.0</version>
  
  </dependency>
  
  <dependency>
  
      <groupid>org.bytedeco</groupid>
  
      <artifactid>javacpp</artifactid>
  
      <version>1.0</version>
  
  </dependency>
  
  <dependency>
  
      <groupid>com.github.hoary.ffmpeg</groupid>
  
      <artifactid>FFmpeg-linux-x86_64</artifactid>
  
      <version>2.0.1.1
  
      </version>
  
  </dependency>
  
  <dependency>
  
      <groupid>org.bytedeco.javacpp-presets</groupid>
  
      <artifactid>ffmpeg</artifactid>
  
      <version>2.7.1-1.0</version>
  
  </dependency>

  This is my code：

  public String convertImage(String filePath, String imagePath) throws IOException, FrameGrabber.Exception {
  
      FFmpegFrameGrabber g = new FFmpegFrameGrabber(filePath);
  
      g.start();
  
      Java2DFrameConverter java2DFrameConverter = new Java2DFrameConverter();
  
      BufferedImage bufferedImage = java2DFrameConverter.convert(g.grabImage());
  
      String path = imagePath + System.currentTimeMillis() + ".png";
  
      ImageIO.write(bufferedImage, "png", new File(path));
  
      g.stop();
  
      return path;
  
  }

• FFmpeg max audio overhead

  15 août 2020, par Alsors

  So I'm encoding videos with FFmpeg. I've set the video stream to have a maximum rate of 6840 kbps and the audio stream to have a constant rate of 160 kbps (AAC) so once they're added together it's a maximum combined rate of 7000 kbps (the maximum rate before my video sharing service re-encodes the video and audio). The problem is sometimes the audio stream likes to go above it's designated constant rate (not by much however enough to take it over 7000 kbps), even with the exact same command it'll sometimes go above and sometime stay the same.

  


  My question : is there a way to calculate the maximum overhead of the audio stream ? I'm assuming FFmpeg has a point where it will not allow the audio rate to go any higher ? What is that exact rate ?

  


• Dash JS Player Cross Browser Compatibility

  21 mai 2015, par JJ The Second

  I am conducting a research for my company streaming service. I found dash.js for adaptive streaming which is a perfect solution along with ffMpeg for transcoding.

  So how this solution works is to create bunch of files served in .mpd format. Now the questions I have :

  1. Do you think this a early stage and I should wait before start using DASH.JS ? Do you think there is a better solution for safe and fast streaming ?

  2. Player options : So far the only player I found was this http://dashif.org/reference/players/javascript/1.0.0/

     I have no idea how compatible it is with browsers and what limits I’ll be facing if I chose it. Is there any other solid solution for this ?

  3. Do you guys think I’m going wrong direction for this ?

  4. What are my server requirements to run these technologies ? I have a 500MBs, 64GB Ram, 24 Core, 2TB beast, does this do the job ?