Recherche avancée

Sur d’autres sites (10982)

• Open avi file with OpenCV : ffmpeg ?

  28 juin 2012, par CTZStef

  This question is related to a previous question I asked here.

  I read on the Willow Garage website dedicated to OpenCV that we do not have to take care of ffmpeg while installing OpenCV since version 1.2.x. Here it is.

  However, some questions asked here on Stackoverflow suggest the contrary.

  So, what should I do ? Do I have to recompile OpenCV and do some special operation related to ffmpeg to get it to, finally, open avi file on my Linux system ?

• Size Discrepany in the ‘du’ Command

  22 juin 2012, par Multimedia Mike — General

  I had a problem today while using the common Unix command ’du’. As a refresher, ’du’ stands for disk usage and is a handy tool for understanding how much disk space is being occupied.

  I think ’du’ is probably doing the right thing. The problem might be that I’m getting strange (read : 1/2 the expected number) when running the tool against directories on vmhgfs, the VMware filesystem.

  Science Project
  On an Ubuntu Linux VMware session, my home directory is on the main file system, which is ext4. The directory /mnt/hgfs is reported by ’mount’ to be of type vmhgfs and is shared with the host machine.

  Create a directory in the home directory and generate a 10 MiB file :

  mkdir /home/melanson/dir
  dd if=/dev/urandom of=/home/melanson/dir/random-file bs=1048576 count=10
  

  Create a directory on the shared drive and copy the same file :

  mkdir /mnt/hgfs/vmshare/dir
  cp /home/melanson/dir/random-file /mnt/hgfs/vmshare/dir
  

  Run ’du’ on each directory using the -k and -h options :

  du -k /home/melanson/dir /mnt/hgfs/vmshare/dir
  10244   /home/melanson/dir
  5120    /mnt/hgfs/vmshare/dir
  du -h /home/melanson/dir /mnt/hgfs/vmshare/dir
  
  11M    /home/melanson/directory
  
  5.0M   /mnt/hgfs/vmshare/directory
  

  I noticed this discrepancy when I was trying to pack a set of files (akin to ’tar’-ing) living in a directory in the shared location. I was going mad trying to understand why the original directory was only 2 MB as reported by ’du’ but the final packed file was 4 MB.

  To be fair, the man page for ’du’ succinctly states that the tool’s purpose is merely to "estimate file space usage".

• Looking for method to combine images to make a video through phonegap platform for android and ios

  28 novembre 2012, par Pat

  I'm looking to write an application that could combine images and then to form a video. I'm working with Phonegap framework to be available for use on Android and IOS.

  My question is what sort of process is involved to achieve this ?

  At this stage I've tried to read about ffmpeg, most of the questions existing on stackoverflow talk of having to get the source, compiling to make a series of libraries for use. With those libraries it needs to be tied in with the Android/IOS libraries ? (I notice there is an 'android.jar' with the project file in eclipse. Would it exist in there ?) Afterwards my confusion lies with how is this implemented into Phonegap. Develop a plugin ?

  Just to add, libav according to wiki, has hardware accelerated H.264 decoding whilst using x.264 for encoding for Android. How does that work ? Is this something accessed from libav libraries and then have to compiled in within the android.jar ?

  I may have confused terms in trying to describe what I do not know.

  Any help would be appreciated.