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• Revision 3276 : Un bouton de déconnexion dans le menu du haut

  19 avril 2010, par kent1 — Log

  Un bouton de déconnexion dans le menu du haut

• Odd X server error with ffmpeg

  4 novembre 2013, par jhc

  I am building a weather data acquisition system. One of the things I would like to do would be to animate the satellite data that is arriving every 15 minutes. In fact, I have already devised a script (called animate) that successfully joins eight hours worth of PNG images into an AVI video file. This runs fine when run manually from the terminal.

  Unfortunately, the same cannot be said when run from my (as in my user, not root) crontab.

  Below is the cron job that I mentioned :

  1,16,31,46 * * * * /home/daniella/bin/anim_all > /home/daniella/logs/anim_all.log 2>&1

  anim_all simply calls animate for each distinct data product :

  #!/bin/bash
  
  set -x
  
  cd /home/daniella/data/imager
  
  
  
  rm -rf HRIT_MSG3_*.avi
  
  
  
  animate HRIT_MSG3_CTT
  
  animate HRIT_MSG3_IR108
  
  animate HRIT_MSG3_VIS006
  
  animate HRIT_MSG3_WV062

  And animate itself calls ffmpeg.

  #!/bin/bash
  
  
  
  set -x
  
  cd /home/daniella/data/imager
  
  product=$1
  
  hl="$product.8hl"
  
  
  
  declare -i i=0
  
  for file in $(cat $hl); do
  
      link=$(printf "images%02d.png" $i)
  
      ln -sf $file $link
  
      i=$((i+1))
  
      echo $i
  
  done
  
  
  
  ffmpeg -sameq -r 15 -i images%02d.png $product.avi
  
  rm -rf images*.png

  Just to be clear, the .8hl file is simply a list of PNG file paths that refer to that last 8 hours of data. Since there is new data every 15 minutes, that is a text file with 32 lines. Finally, this is the error that is returned when examining anim_all.log (referred in the crontab) file.

  + animate HRIT_MSG3_CTT
  
  animate: unable to open X server `' @ animate.c/AnimateImageCommand/365.
  
  + animate HRIT_MSG3_IR108
  
  animate: unable to open X server `' @ animate.c/AnimateImageCommand/365.
  
  + animate HRIT_MSG3_VIS006
  
  animate: unable to open X server `' @ animate.c/AnimateImageCommand/365.
  
  + animate HRIT_MSG3_WV062
  
  animate: unable to open X server `' @ animate.c/AnimateImageCommand/365.

  Please note that anim_all works fine, when called manually from the terminal. This error exists only when called by cron. I would imagine that this has to do with environment variables, but I have sourced my .bashrc inside the script to no prevail.

  EDIT -
  Investigating the animate.c file itself (see the full code here), at lines 365-368, there is this :

  if (display == (Display *) NULL)
  
      ThrowAnimateException(XServerError,"UnableToOpenXServer",
  
      XDisplayName(server_name));
  
  (void) XSetErrorHandler(XError);

  In response, I have attempted to export the $DISPLAY variable to 127.0.0.0:0 in the animate script, but this has not worked.

• Recapping WebM’s First Week

  25 mai 2010, par noreply@blogger.com (John Luther) — webm, vp8, vorbis

  The WebM project launched last Wednesday with broad industry backing (watch video of the announcement). The list of supporters keeps growing with new additions such as the popular VLC media player, Miro Video Converter, HeyWatch cloud encoding platform, and videantis programmable processor platform. We’re also happy to see that future versions of IE will support playback of VP8 when the user has installed the codec.

  Our announcement sparked discussions in the community around the design and quality of our developer release. We’ve done extensive testing of VP8 and know that the codec can match or exceed the quality of other leading codecs. Starting this week, the engineers behind WebM will post frequently to this blog with details on how to make optimal use of its VP8 video codec and Vorbis audio codec. We are confident that the open development model will bring additional improvements that will further optimize WebM. In fact, the power of open development is already visible, with developers submitting patches and the folks at Flumotion enabling live streaming support in their product just three days after the project was launched.

  Keep an eye on this blog for regular updates on the adoption and development of WebM. To participate in the conversation or to ask questions of the WebM team, please join our discussion group.

  John Luther
  Product Manager, Google