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• Maven dependency works on machine but not when packaged in a .war - org.bytedeco.javacpp.avutil

  26 décembre 2016, par Jake Miller

  I have a web app where you can upload a video and a thumbnail is created for this video. It works completely fine on my machine, but as soon as I deploy to AWS (Amazon Web Services) as a .war file, I experience dependency issues with maven.

  Here’s the exception from the logs :

  Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.bytedeco.javacpp.avutil
  
      at java.lang.Class.forName0(Native Method) ~[na:1.8.0_101]
  
      at java.lang.Class.forName(Class.java:348) ~[na:1.8.0_101]
  
      at org.bytedeco.javacpp.Loader.load(Loader.java:472) ~[javacpp-1.2.1.jar!/:1.2.1]
  
      at org.bytedeco.javacpp.Loader.load(Loader.java:417) ~[javacpp-1.2.1.jar!/:1.2.1]
  
      at org.bytedeco.javacpp.avformat$AVFormatContext.<clinit>(avformat.java:2597) ~[ffmpeg-2.8.1-1.1.jar!/:1.2.1]
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:391) ~[javacv-1.2.jar!/:1.2]
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:385) ~[javacv-1.2.jar!/:1.2]
  
      at com.myapp.app.service.ICampaignService.createThumbnail(ICampaignService.java:425) ~[classes!/:0.0.44T-SNAPSHOT]
  
      at com.myapp.app.service.ICampaignService$$FastClassBySpringCGLIB$$47736265.invoke(<generated>) ~[classes!/:0.0.44T-SNAPSHOT]
  
      at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:720) ~[spring-aop-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:280) ~[spring-tx-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655) ~[spring-aop-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at com.myapp.app.service.ICampaignService$$EnhancerBySpringCGLIB$$67e59894.createThumbnail(<generated>) ~[classes!/:0.0.44T-SNAPSHOT]
  
      at com.myapp.app.controllers.CampaignController.uploadCampaign(CampaignController.java:237) ~[classes!/:0.0.44T-SNAPSHOT]
  
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
  
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
  
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
  
      at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
  
      at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221) ~[spring-web-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114) ~[spring-webmvc-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.2.RELEASE.jar!/:4.3.2.RELEASE]
  
      ... 85 common frames omitted
  
  </generated></generated></clinit>

  Here are my maven dependencies for the ffmpeg wrapper I’m using :

  <dependency>
  
      <groupid>org.bytedeco</groupid>
  
      <artifactid>javacv</artifactid>
  
      <version>1.3</version>
  
  </dependency>
  
  <dependency>
  
      <groupid>org.bytedeco</groupid>
  
      <artifactid>javacpp</artifactid>
  
      <version>1.3</version>
  
  </dependency>

  I’ve tried various different versions but nothing has worked so far. What’s strange is the error says org.bytedeco.javacpp.avutil but I have access to the avutil class in my IDE.

  EDIT

  I’ve also tried everything at this github post : https://github.com/bytedeco/javacpp-presets/issues/225

  No solution I’ve found has worked. I’ve tried various different versions and various different org.bytedeco dependencies but they all yield the same error.

• ffmpeg stream chrome kiosk mode ubuntu 16.04 server

  21 décembre 2016, par Raul

  I have a weird out-of-sync issue while using ffmpeg to stream to youtube live a chrome browser from an ub untu 16.04 server.

  Issue : output video streamed to youtube has audio/video out of sync, sometimes with as much as 3s

  Current flow :

  1) start pulseaudio - we using something like this to start it :

  pulseaudio --start -vvv --disallow-exit --log-target=syslog --high-priority --exit-idle-time=-1 --daemonize

  2) start Xvfb

  Xvfb :0 -ac -screen 0 1920x1080x24

  3) start chrome linux in kiosk mode

  google-chrome --kiosk --disable-gpu --incognito --no-first-run --disable-java --disable-plugins --disable-translate --disk-cache-size=$((1024 * 1024)) --disk-cache-dir=/tmp/chrome/ --user-data-dir=/tmp/chrome/ --force-device-scale-factor=1 --window-size=1920,1080 --window-position=0,0 LOCATION_URL

  4) start ffmpeg

  ffmpeg -y \
  
    -thread_queue_size 8192 -rtbufsize 250M -f x11grab -video_size 1920x1080 -framerate 24 -i :0 \
  
    -thread_queue_size 8192 -channel_layout stereo -f alsa -i pulse \
  
    -c:v libx264 -pix_fmt yuv420p -c:v libx264 -g 48 -crf 24 -filter:v fps=24 -preset ultrafast -tune zerolatency \
  
    -c:a aac -strict -2 -channel_layout stereo -ab 96k -ac 2 -flags +global_header \
  
    -f flv YOUTUBE_LIVE_STREAMING_RTMP

  Note : this is running on an amazon ec2 instance, meaning there is no soundcard, so alsa and pulseaudio are creating a dummy audio card. However, the latency does not come from there. Logs :

  Nov 25 06:14:22 ip-172-31-29-8 pulseaudio[26602]: [pulseaudio] protocol-native.c: Adjust latency mode enabled, configuring sink latency to half of overall latency.
  
  Nov 25 06:14:22 ip-172-31-29-8 pulseaudio[26602]: [pulseaudio] protocol-native.c: Requested latency=23.22 ms, Received latency=23.22 ms
  
  Nov 25 06:14:22 ip-172-31-29-8 pulseaudio[26602]: [pulseaudio] protocol-native.c: Final latency 69.66 ms = 23.22 ms + 2*11.61 ms + 23.22 ms

  At this point, here’s what we observed :

  1. if we start ffmpeg exactly after issuing the command to start chrome, we see the DTS errors from ffmpeg. Audio is out of sync with the video and has delay of 3-5seconds AHEAD. We also noticed the out of sync remains the same for the full duration of the stream

  2. if we start ffmpeg after around 10seconds, audio and video are almost in sync. We then manually added a -itsoffset -0.125 to the ffmpeg command and everything is perfect.

  Questions :

  1. Why would ffmpeg have so much lag if it’s started right after chrome ?
  2. Is starting the ffmpeg after 10s or X seconds the expected behavior ? That is, is this because the system needs to wait for audio/video signals to be "ready" or something ?
  3. Is there a way to 100% calculate or know when Chrome is fully ready and start ffmpeg ? We found sometimes it takes 5s, sometimes 10. Depends on the URL we load.
  4. Besides the DTS error that ffmpeg throws, is there any other way to know if audio/video is out-of-sync ? as sometimes we have a delay of between 0.5 to 1s, but ffmpeg does not report anything. And a restart is required to "re-balance" the audio/video inputs and get them back in sync.
  5. Can pulseaudio be the problem in this scenario ?

  Thank you

  UPDATE Dec 20

  We were able to do some tricks to force chrome to start the audio on page load, and that will force connect to pulseaudio. Doing that, plus adding a 3s delay for ffmpeg to start, there is no more delay when ffmpeg starts.
  However, our app is a webRTC app, and we have a STRANGER thing happening : if we start the page with no webcam/audio, once the webcam/audio is enabled, ffmpeg (while showing no errors) has a delay of 2s or so. While keep talking, in about max 30s, that delay is GONE.

  So the new questions are :

  1. Besides the DTS error that ffmpeg throws, is there any other way to know if audio/video is out-of-sync ? as sometimes we have a delay of between 0.5 to 1s, but ffmpeg does not report anything.
  2. What could cause the initial audio/video out of sync issue and then catching up ?

• java.lang.NoClassDefFoundError : Could not initialize class on Linux (Works fine on Windows)

  26 décembre 2016, par Jake Miller

  I’m using a C++ FFmpeg wrapper for Java (org.bytedeco.javacpp). This works perfectly on a Windows machine (my development machine) but throws this error when ran on Linux (Amazon Web Services Elastic Beanstalk) :

  java.lang.NoClassDefFoundError: Could not initialize class org.bytedeco.javacpp.avutil
  
      at java.lang.Class.forName0(Native Method) ~[na:1.8.0_111]
  
      at java.lang.Class.forName(Class.java:348) ~[na:1.8.0_111]
  
      at org.bytedeco.javacpp.Loader.load(Loader.java:472) ~[javacpp-1.2.1.jar!/:1.2.1]
  
      at org.bytedeco.javacpp.Loader.load(Loader.java:417) ~[javacpp-1.2.1.jar!/:1.2.1]
  
      at org.bytedeco.javacpp.avformat$AVFormatContext.<clinit>(avformat.java:2819) ~[ffmpeg-3.2.1-1.3.jar!/:1.2.1]
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:391) ~[javacv-1.3.jar!/:1.3]
  
      at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:385) ~[javacv-1.3.jar!/:1.3]
  
  </clinit>

  I’ve been troubleshooting for the past 2 days and have tried the following to fix the issue :

  • upgrade to Linux to 2.4
  • downgrading javacpp to 1.2.1
  • running mvn clean
  • running mvn -U
  • deleting contents of /.m2/ and redownloading dependencies
  • various combinations of dependency versions
  • git clone on a Linux VM & running mvn install there

  When looking further into the issue, I stumbled upon documentation for avformat$AVFormatContext as it’s in the stack trace posted above (6th line). The documentation for a C++ class named AVFormatContext. Whenever I attempt to view the class in Eclipse, it says Source Not Found.

  My question : could this problem possibly be caused by the C++ libraries on my Linux VM ? None of the above solutions fixed it so this is my only hypothesis as of now.

  Here’s my other Stack Overflow question regarding this subject : Java.lang.NoClassDefFoundError caused by FFmpeg when deployed on Linux as a packaged .war (Works on development machine)