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• Undefined references to swscale functions

  22 novembre 2015, par rightaway717

  My app fails to link to swscale library at all. I mean that any swscale method I’m trying to use in my code becomes an undefined reference.
  I know what this error means - a linker couldn’t find any definition of used functions.

  But the problem is that I made sure that :

  1. -L/usr/local/Cellar/ffmpeg/2.8.2/lib -lswscale is in linker output, and the linker actually finds the lib, otherwise it would complain about missing swscale

  2. The library is really there :

     $ll /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale*

  output :

  -r--r--r--  1 myuser  admin   519K Nov 20 19:33 /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.3.1.101.dylib
  
  lrwxr-xr-x  1 myuser  admin    24B Nov 20 19:32 /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.3.dylib -> libswscale.3.1.101.dylib
  
  -r--r--r--  1 myuser  admin   607K Nov 20 19:32 /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.a
  
  lrwxr-xr-x  1 myuser  admin    24B Nov 20 19:32 /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.dylib -> libswscale.3.1.101.dylib

  3. The library is of the correct architecture :

     $lipo -info /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.3.dylib

  output :

   Non-fat file: /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.3.dylib is architecture: x86_64

  My machine architecture :

  $uname -m

  output :

  x86_64

  4. The symbols exist in the binary, for example :

     $nm /usr/local/Cellar/ffmpeg/2.8.2/lib/libswscale.3.1.101.dylib | grep sws_alloc_context

  output :

  000000000004e3b4 T _sws_alloc_context

  5. I also tried a couple of different swscale binaries, not only the "brew" ones, but nothing changed. I also tried to do the same on my Ubuntu laptop, but it is still the same.

  This is actually a QT app I’m trying to build. I should mention, that I don’t have issues with linking other libraries the same way.
  I also compiled successfully swscale-test.c (which is in libwscale sources) using :

  clang swscale-test.c -lswscale -lavutil

  Do you have any ideas what is wrong or what else can I try to find out the reason ?

• Video Codec For Commercial Use [on hold]

  17 décembre 2015, par mFeinstein

  I am new in video programming and I need to make a commercial application that needs to export some video. I was going to use OpenCV, but the documentation says it can’t write a video larger than 2Gb and that’s not something that my project can tolerate.

  I have an industrial camera and I will receive each frame of the camera in my C++ code and I want to transform the frames in a video. So far I am thinking about using FFmpeg for the video generation, but I am afraid of all these patented codecs.

  Are there any codecs that are free for commercial use ?

  Edit :

  Some are flaging this post as not related to programing or opinion based.

  1. I am not asking for an opinion, but a list of commercial free codecs. I am not asking which are good or bad (which is opinion based) I just can’t find a list online.

  2. This is about programing, there are lots of posts here in SO about legal issues on software like licensing, there is even one with a "legal" tag. I found many posts related to codecs licenses but none with a list of free ones. Of course this is programing related, I will develop and architecture my code around my options.

• We are hiring engineers to build an awesome product and platform used by millions of people

  16 février 2016, par Piwik Core Team — Uncategorized

  Are you ready for a new challenge ? Or maybe you know someone who is looking for a change ? We have some exciting problems to solve and are looking for senior developers to work with us and our community on our open source Piwik Analytics platform. Piwik is used by more than one million websites all over the world. It is deployed on more than 300.000 servers and some users track more than 1 billion actions per month.

  What is it like to work on Piwik ?

  We develop this software using modern PHP, MySQL, Redis, AngularJS and more. We provide several kind of APIs and a plugin architecture to allow developers to extend and change Piwik to their needs. However, we would not be Piwik if we stopped at this point ! We want to turn Piwik into an even more awesome product and platform.
  You can imagine there is a lot to do and many challenges to face !

  While one part is to always make Piwik scale better and to improve UI and UX, we also want to provide simple APIs to make the life of developers as pleasant as possible. We aim to solve things the right way and our thousands of unit, integration, system, JavaScript and screenshot tests help us to innovate and to not be afraid of change. We like clean code and constant improvements.

  The Piwik team lives in New Zealand and Europe (Germany). We do the vast majority of our collaboration online. Our values include being open, transparent and sharing knowledge. For this we use tools like GitHub and Slack to communicate and Quake servers to take our minds off complex challenges. We are a small, flexible team, so when you come aboard, you will play an integral part in engineering and have a big impact on the product loved by so many people. You’ll help to create a welcoming environment for new contributors and set an example with your development practices and communications skills.

  Apply now, or spread the word !

  If you have strong skills in PHP send us an email with your CV and tell us a little about yourself and your experience in engineering complex applications.

  Apply for a job here http://piwik.org/jobs/ and if you’re maybe not the right candidate, contribute to the project by sharing this blog post and by sending it to your friends !