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• FFmpeg linker error : Error due to text relocations in libavcodec shared object

  19 janvier 2016, par Balaraman L

  I am trying to build an Android app which uses FFmpeg native code for video decoding and encoding. I have a 64-bit machine running 32-bit Ubuntu 14.04, ADT version 23. I downloaded FFmpeg-2.4.4 (32-bit) and built it for Android following the steps mentioned here - http://www.roman10.net/how-to-build-ffmpeg-with-ndk-r9/

  I used latest Android NDK, that is NDK r10c. For testing, I used FFmpeg’s API example code given in this link - http://ffmpeg.org/doxygen/trunk/decoding__encoding_8c-source.html

  I was able to build all the shared objects successfully and Android project gets compiled successfully without any errors.

  Following code is Android code to load all shared objects

  public class CallNative {
  
  public static String libName = "decode_encode" ;
  
  public CallNative(){
  
      System.loadLibrary("avutil-54");
  
      System.loadLibrary("swresample-1");
  
      System.loadLibrary("avcodec-56");
  
      System.loadLibrary("avformat-56");
  
      System.loadLibrary("swscale-3");
  
      System.loadLibrary("avfilter-5");
  
      System.loadLibrary(libName);
  
  }
  
  
  
  public native int decode(String Filename, int length);

  }

  And, this is how, decode function is called from Android.

  Uri videoURI = Uri.parse(fileUri.toString());
  
                     String videoFilePath = getFilePathFromURI(getApplicationContext(), videoURI);
  
                     Log.d("SPLASH","Entering native decode call");
  
                     CallNative n = new CallNative();
  
                     n.decode(videoFilePath, videoFilePath.length());
  
                     Log.d("SPLASH","successfully returned from decode call");

  When I debugged, App crashes when it enters native function call. I get following linker error.

  W/linker(32244): libavcodec-56.so has text relocations. This is wasting memory and prevents security hardening. Please fix.

  I tried the same with FFmpeg 2.4.3 and 2.0.6 packages as well. I am getting the same error.

  How to resolve this ?

• Paid Advertising Performance – target the right customers and invest confidently

  21 avril 2020, par Joselyn Khor — Development, Marketing, Plugins
  You can now analyse the success of your Google Ads campaigns and accounts directly in your Matomo with ease. See what keywords and search queries are leading to clicks for your paid ads and bringing your business the highest ROI, right down to devices and networks – for more effective targeting.

  For many Matomo users, Google Ads is the lifeline for their business. If people are looking for products you sell, you’ll want them to find you first.

  Invest confidently in the right keywords and target the right customers for higher ROI

  You can accurately measure the success of your impressions, clicks, costs, CPC and CPAs and see how they directly relate to the goals you’ve created in your Matomo.

  -> Read the rest of the story on the Form Analytics Marketplace page.

  What does the new Paid Advertising Performance feature look like ?

  The PPC Advertising Performance plugin integrates seamlessly with Matomo’s Row Evolution feature to show you how the performance of your campaigns change over time. This way you can see if the changes you’ve made have a positive or negative effect on sales over time.

  

  The Visitor Profiles feature is also integrated within the plugin so you can get a detailed overview of everyone who clicks on your ads. This will tell you if they have visited your website in the past and to what extent, so you can identify and target more like-minded customers for more sales when setting up your next campaign.

  

  Where do I get the Paid Advertising Performance feature ?

  Paid Advertising Performance is available on the Matomo Marketplace :

  Get the Paid Advertising Performance feature here

  Learn more from the PaidAdvertisingPerformance user guide and FAQs.

• What Every Programmer Should Know

  24 décembre 2012, par Multimedia Mike — General

  During my recent effort to force myself to understand Unicode and modern text encoding/processing, I was reminded that this is something that “every programmer should just know”, an idea that comes up every so often, usually in relation to a subject in which the speaker is already an expert. One of the most absurd examples I ever witnessed was a blog post along the lines of “What every working programmer ought to know about [some very specific niche of enterprise-level Java programming]“. I remember reading through the article and recognizing that I had almost no knowledge of the material. Disturbing, since I am demonstrably a “working programmer”.

  For fun, I queried the googles on the matter of what ever programmer ought to know.

  Specific Topics
  Here is what every programmer should know about : Unicode, time, memory (simple), memory (extremely in-depth), regular expressions, search engine optimization, floating point, security, basic number theory, race conditions, managed C++, VIM commands, distributed systems, object-oriented design, latency numbers, rate monotonic algorithm, merging branches in Mercurial, classes of algorithms, and human names.

  Broader Topics
  20 subjects every programmer should know, 97 things every programmer should know, 12 things every programmer should know, things every programmer should know (27 items), 10 papers every programmer should read at least twice, 10 things every programmer should know for their first job.

  Meanwhile, I remain fond of this xkcd comic whose mouseover text describes all that a person genuinely needs to know. Still, the new year is upon us, a time when people often make commitments to bettering themselves, and it couldn’t hurt (much) to at least skim some of the lists and find out what you never knew that you never knew.

  What About Multimedia ?
  Reading the foregoing (or the titles of the foregoing pieces), I naturally wonder if I should write something about what every programmer should know about multimedia. I think it would look something like a multimedia programming FAQ. These are some items that I can think of :

  1. YUV : The other colorspace (since most programmers are only familiar with RGB and have no idea what to make of the YUV that comes out of most video decoding APIs)
  2. Why you can’t easily seek randomly to any specific frame in a video file (keyframe/interframe discussion and their implications)
  3. Understand your platform before endeavoring to implement multimedia software (modern platforms, particularly mobile platforms, probably provide everything you need in the native APIs and there is likely little reason to compile libavcodec for the platform)
  4. Difference between containers and codecs (longstanding item, but I would argue it’s less relevant these days due to standardization on the MPEG — MP4/H.264/AAC — stack)
  5. What counts as a multimedia standard in this day and age (comparing the foregoing MPEG stack with the WebM/VP8/Vorbis stack)
  6. Trade-offs to consider when engineering a multimedia solution
  7. Optimization doesn’t always work the way you think it does (not everything touted as a massive speed-up in the world of computing — whether it be multithreaded CPUs, GPGPUs, new SIMD instruction sets — will necessarily be applicable to multimedia processing)
  8. A practical guide to legal issues would not be amiss
  9.  ???

  What other items count as “something multimedia-related that every programmer should know” ?