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• Using openCV library with Java works well on Linux but not on Windows

  6 août 2016, par user3586330

  I have a method that takes screenshots on absolute intervals (25%, 50%, 75% and 100%) from a video-file and save each of them to a separate .png-file. I use openCV with the JavaCV-Wrapper library to do that. The class/method of interest is :

  package de.stal.videoreporter;
  
  
  
  import org.bytedeco.javacpp.opencv_core;
  
  import static org.bytedeco.javacpp.opencv_imgcodecs.cvSaveImage;
  
  import org.bytedeco.javacv.FFmpegFrameGrabber;
  
  import org.bytedeco.javacv.Frame;
  
  import org.bytedeco.javacv.FrameGrabber;
  
  import org.bytedeco.javacv.OpenCVFrameConverter;
  
  
  
  class VideoThumbnailer {
  
  public void createThumbnails(String videoname) throws FrameGrabber.Exception {
  
  
  
      FFmpegFrameGrabber g = new FFmpegFrameGrabber("videos/" + videoname);
  
      g.start();
  
      OpenCVFrameConverter.ToIplImage converterToIplImage = new OpenCVFrameConverter.ToIplImage();
  
      int length = g.getLengthInFrames();
  
      int fifty = length / 2;
  
      int twentyfive = fifty / 2;
  
      int seventyfive = fifty + twentyfive;
  
      int hundred = length - 1;
  
  
  
      //each frame of video
  
      for (int j = 0; j < length; j++) {
  
  
  
          if (j == twentyfive || j == fifty || j == seventyfive || j == hundred) {
  
              String ss = "";
  
              if (j == twentyfive) {
  
                  ss = "25";
  
              } else if (j == fifty) {
  
                  ss = "50";
  
              } else if (j == seventyfive) {
  
                  ss = "75";
  
              } else if (j == hundred) {
  
                  ss = "100";
  
              }
  
  
  
              g.setFrameNumber(j);
  
  
  
              Frame f = g.grabImage();
  
  
  
              opencv_core.IplImage image = converterToIplImage.convert(f);
  
              String img_path = "thumbnails/" + videoname + "." + ss + ".png";
  
              cvSaveImage(img_path, image);
  
          }
  
  
  
      }
  
      g.stop();
  
  }
  
  }

  That works fine on environment : Ubuntu 15.10 x64, Java v.1.7.0_101 and Netbeans 8.0.2 with Maven. So I exported the project to a runnable jar-file(with all dependencies included) and tried to start it on Windows 10 x64 via :

  java -jar VideoReporter-1.0-SNAPSHOT-jar-with-dependencies.jar

  On Windows an exception will be thrown when executing the .jar-file :

  Error putting member offsets for class org/bytedeco/javacpp/avutil$Pool_free_Pointer.
  
  Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class org.bytedeco.javacpp.avutil
  
      at java.lang.Class.forName0(Native Method)
  
      at java.lang.Class.forName(Unknown Source)
  
      at org.bytedeco.javacpp.Loader.load(Loader.java:472)
  
      at org.bytedeco.javacpp.Loader.load(Loader.java:417)
  
      at org.bytedeco.javacpp.avformat$AVFormatContext.<clinit>(avformat.java:2719)
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:391)
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:385)
  
      at de.stal.videoreporter.VideoThumbnailer.createThumbnails(VideoThumbnailer.java:15)
  
      at de.stal.videoreporter.MetaReader.slurpMetadata(MetaReader.java:67)
  
      at de.stal.videoreporter.VideoReporter.main(VideoReporter.java:19)
  
  </clinit>

  My pom.xml is :

  <?xml version="1.0" encoding="UTF-8"?>
  
  <project xmlns="http://maven.apache.org/POM/4.0.0">
  
  <modelversion>4.0.0</modelversion>
  
  <groupid>de.stal</groupid>
  
  <artifactid>VideoReporter</artifactid>
  
  <version>1.0-SNAPSHOT</version>
  
  <packaging>jar</packaging>
  
  <properties>
  
      UTF-8
  
      1.7
  
      1.7
  
  </properties>
  
  <build>
  
      <plugins>
  
          <plugin>
  
              <artifactid>maven-assembly-plugin</artifactid>
  
              <configuration>
  
                  <archive>
  
                      <manifest>
  
                          <mainclass>de.stal.videoreporter.VideoReporter</mainclass>
  
                      </manifest>
  
                  </archive>
  
                  <descriptorrefs>
  
                      <descriptorref>jar-with-dependencies</descriptorref>
  
                  </descriptorrefs>
  
              </configuration>
  
              <executions>
  
                  <execution>
  
                      <id>make-assembly</id>
  
                      <phase>package</phase> 
  
                      <goals>
  
                          <goal>single</goal>
  
                      </goals>
  
                  </execution>
  
              </executions>
  
          </plugin>
  
      </plugins>
  
  </build>
  
  <dependencies>
  
      <dependency>
  
          <groupid>org.apache.commons</groupid>
  
          <artifactid>commons-csv</artifactid>
  
          <version>1.1</version>
  
      </dependency>
  
      <dependency>
  
          <groupid>org.bytedeco</groupid>
  
          <artifactid>javacpp</artifactid>
  
          <version>1.2.1</version>
  
      </dependency>
  
      <dependency>
  
          <groupid>org.bytedeco</groupid>
  
          <artifactid>javacv</artifactid>
  
          <version>1.2</version>
  
      </dependency>
  
      <dependency>
  
          <groupid>com.fasterxml.jackson.dataformat</groupid>
  
          <artifactid>jackson-dataformat-csv</artifactid>
  
          <version>2.8.0.rc2</version>
  
      </dependency>
  
      <dependency>
  
          <groupid>javassist</groupid>
  
          <artifactid>javassist</artifactid>
  
          <version>3.12.1.GA</version>
  
      </dependency>
  
      <dependency>
  
          <groupid>commons-collections</groupid>
  
          <artifactid>commons-collections</artifactid>
  
          <version>3.2.1</version>
  
      </dependency>
  
      <dependency>
  
          <groupid>com.opencsv</groupid>
  
          <artifactid>opencsv</artifactid>
  
          <version>3.3</version>
  
      </dependency>
  
  </dependencies>
  
  </project>

  What might be the problem on Windows ? In my opinion there shouldn’t be a problem with access to openCV/FFMPEG-classes because they all have been included the .jar-file ? Is this a problem with the classpath ?

  Thanks, Peter

• dash.js : four channels audio streaming

  19 juillet 2016, par Carlos Chacon

  Does dash.js supports 4 channels in the audio stream ?

  I’m using mp4 container : video : h254 and audio : AAC.

  For the case that the AAC audio stream is 2 channels it works fine, both video and audio play correctly. But 4 channels does NOT work.

  I’m using FFMPEG to create the files and WOWZA to setup the DASH streaming.

  For the case that the AAC audio stream is 4 channels I get the following error :

   Video can't be played because the file is corrupt.

  Command line to generate the 2-channels file :

  ffmpeg -i video_in.mp4 -i audio_in_4ch.wav -c:v copy -c:a aac -ac 2 output_2channels.mp4

  Command line to generate the 4-channels file :

  ffmpeg -i video_in.mp4 -i audio_in_4ch.wav -c:v copy -c:a aac -ac 4 output_4channels.mp4

  This is the fmmpeg -i information printed for each file :

  2 Channels output file details :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output_2channels.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.37.101
  
    Duration: 00:00:17.59, start: 0.000000, bitrate: 901 kb/s
  
      Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1024x512 [SAR 1:1 DAR 2:1], 894 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 129 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

  4 Channels output file details :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output_4channels.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.37.101
  
    Duration: 00:00:17.59, start: 0.000000, bitrate: 1038 kb/s
  
      Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1024x512 [SAR 1:1 DAR 2:1], 894 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 4.0, fltp, 265 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

  4 Channels output file mdp file :

  <?xml version="1.0" encoding="UTF-8"?>
  
  <mpd xmlns="urn:mpeg:dash:schema:mpd:2011" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="static" publishtime="2016-07-19T05:56:28Z" mediapresentationduration="PT17.585S" minbuffertime="PT1.5S">
  
  <programinformation>
  
      
  
  </programinformation>
  
  <location>http://192.168.0.103:1935/vod/_definst_/mp4:output_4channels.mp4/manifest_w882219731.mpd</location>
  
  <period start="PT0.0S">
  
      <baseurl>http://192.168.0.103:1935/vod/_definst_/mp4:output_4channels.mp4/</baseurl>
  
      <adaptationset mimetype="video/mp4" width="1024" height="512" par="1024:512" framerate="30000/1001" segmentalignment="true" startwithsap="1" subsegmentalignment="true" subsegmentstartswithsap="1">
  
          <segmenttemplate presentationtimeoffset="0" timescale="90000" media="chunk_ctvideo_rid$RepresentationID$_cs$Time$_w882219731_mpd.m4s" initialization="chunk_ctvideo_rid$RepresentationID$_cinit_w882219731_mpd.m4s">
  
              <segmenttimeline>
  
                  <s t="0" d="1582650"></s>
  
              </segmenttimeline>
  
          </segmenttemplate>
  
          <representation codecs="avc1.42c01e" sar="1:1" bandwidth="894760"></representation>
  
      </adaptationset>
  
      <adaptationset mimetype="audio/mp4" lang="eng" segmentalignment="true" startwithsap="1" subsegmentalignment="true" subsegmentstartswithsap="1">
  
          <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"></audiochannelconfiguration>
  
          <segmenttemplate presentationtimeoffset="0" timescale="48000" media="chunk_ctaudio_rid$RepresentationID$_cs$Time$_w882219731_mpd.m4s" initialization="chunk_ctaudio_rid$RepresentationID$_cinit_w882219731_mpd.m4s">
  
              <segmenttimeline>
  
                  <s t="0" d="844080"></s>
  
              </segmenttimeline>
  
          </segmenttemplate>
  
          <representation codecs="mp4a.40.2" audiosamplingrate="48000" bandwidth="265851">
  
          </representation>
  
      </adaptationset>
  
  </period>
  
  </mpd>

  HTML Player Code :

  <code class="echappe-js">&lt;script src=&quot;http://cdn.dashjs.org/latest/dash.all.min.js&quot;&gt;&lt;/script&gt;
  
         
  
  

• dashjs can't find initialization segment on manifest.mpd

  30 avril 2016, par Abelardo Mendoza

  I am following this tutorial to stream a WebM. I have no issues running the ffmpeg commands to generate the videos/audio/manifest files but when I try to run it locally, there’s no video or audio at all and dashjs floods the console with :

  Searching for initialization.    
  
  Start searching for initialization.     
  
  Perform init search: http://localhost:8080/video_1280x720_500k.webm    
  
  Perform SIDX load: http://localhost:8080/video_640x360_750k.webm     
  
  Perform SIDX load: http://localhost:8080/video_1280x720_500k.webm 

  Writing that to console until I stop the server. I have tried using other mpd files such as this, which is used on the dashjs quickstart and it plays the video without any problems.

  I used this guide to install the latest version of ffmpeg on Ubuntu 14.04 LTS :

  ffmpeg version N-79688-g3cb3ddd Copyright (c) 2000-2016 the FFmpeg developers
  
  built with gcc 5.3.0 (Ubuntu 5.3.0-3ubuntu1~14.04) 20151204
  
  configuration: --prefix=/home/ab/cpp/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/ab/cpp/ffmpeg_build/include --extra-ldflags=-L/home/ab/cpp/ffmpeg/lib --bindir=/home/ab/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree
  
  libavutil      55. 23.100 / 55. 23.100
  
  libavcodec     57. 38.100 / 57. 38.100
  
  libavformat    57. 34.103 / 57. 34.103
  
  libavdevice    57.  0.101 / 57.  0.101
  
  libavfilter     6. 44.100 /  6. 44.100
  
  libswscale      4.  1.100 /  4.  1.100
  
  libswresample   2.  0.101 /  2.  0.101
  
  libpostproc    54.  0.100 / 54.  0.100

  When running on ffmpeg :

  ffmpeg \
  
   -f webm_dash_manifest -i video_160x90_250k.webm \
  
   -f webm_dash_manifest -i video_320x180_500k.webm \
  
   -f webm_dash_manifest -i video_640x360_750k.webm \
  
   -f webm_dash_manifest -i video_640x360_1000k.webm \
  
   -f webm_dash_manifest -i video_1280x720_500k.webm \
  
   -f webm_dash_manifest -i audio_128k.webm \
  
   -c copy -map 0 -map 1 -map 2 -map 3 -map 4 -map 5 \
  
   -f webm_dash_manifest \
  
   -adaptation_sets "id=0,streams=0,1,2,3,4 id=1,streams=5" \
  
   manifest.mpd

  It generates the following manifest.mpd :

  <?xml version="1.0" encoding="UTF-8"?>
  
  <mpd xmlns="urn:mpeg:DASH:schema:MPD:2011" type="static" mediapresentationduration="PT117.726S" minbuffertime="PT1S" profiles="urn:webm:dash:profile:webm-on-demand:2012">
  
    <period start="PT0S" duration="PT117.726S">
  
      <adaptationset mimetype="video/webm" codecs="vp9" lang="eng" bitstreamswitching="true" subsegmentalignment="true" subsegmentstartswithsap="1">
  
        <representation bandwidth="198155" width="160" height="90">
  
          <baseurl>video_160x90_250k.webm</baseurl>
  
          <segmentbase indexrange="2007834-2008211">
  
            <initialization range="0-437"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="459264" width="320" height="180">
  
          <baseurl>video_320x180_500k.webm</baseurl>
  
          <segmentbase indexrange="4459996-4460374">
  
            <initialization range="0-439"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="718495" width="640" height="360">
  
          <baseurl>video_640x360_750k.webm</baseurl>
  
          <segmentbase indexrange="6614036-6614414">
  
            <initialization range="0-441"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="931445" width="640" height="360">
  
          <baseurl>video_640x360_1000k.webm</baseurl>
  
          <segmentbase indexrange="8309082-8309460">
  
            <initialization range="0-441"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="821274" width="1280" height="720">
  
          <baseurl>video_1280x720_500k.webm</baseurl>
  
          <segmentbase indexrange="8728812-8729190">
  
            <initialization range="0-441"></initialization>
  
          </segmentbase>
  
        </representation>
  
      </adaptationset>
  
      <adaptationset mimetype="audio/webm" codecs="vorbis" lang="eng" audiosamplingrate="44100" bitstreamswitching="true" subsegmentalignment="true" subsegmentstartswithsap="1">
  
        <representation bandwidth="107104">
  
          <baseurl>audio_128k.webm</baseurl>
  
          <segmentbase indexrange="1538710-1539184">
  
            <initialization range="0-4112"></initialization>
  
          </segmentbase>
  
        </representation>
  
      </adaptationset>
  
    </period>
  
  </mpd>

  The index.html has a few changes because dash.js changed the way the player gets initialized.

      
  
          
  
          
  
          <code class="echappe-js">&lt;script src=&quot;http://cdn.dashjs.org/latest/dash.all.debug.js&quot;&gt;&lt;/script&gt;
  
              
          
  

  And here is Chromium’s log file. I’m converting this webm from this site.

  If I missed out any other relevant information or if anyone can guide me into the right direction, please let me know.

  Edit :

  Like Will Law mentioned, using the Shaka Player worked without any issues with my current manifest. Hope this helps anyone else.