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• Multimedia Exploration Journal : The Past Doesn’t Die

  12 juillet 2011, par Multimedia Mike — Game Hacking

  New haul of games, new (old) multimedia formats.

  Lords of Midnight
  Check out the box copy scan for Lords of Midnight in MobyGames. In particular, I’d like to call your attention to this little blurb :

  
  
  

  Ahem, "Journey through an immense world — the equivalent of 8 CD-ROMs." Yet, when I procured the game, it only came on a single CD-ROM. It’s definitely a CD-ROM (says so on the disc) and, coming from 1995, certainly predates the earliest DVD-ROMs (which can easily store 8 CD-ROMs on a disc). Thus, I wanted to jump in a see if they were using some phenomenal compression in order to squeeze so much info into 600 or so megabytes.

  I was surprised to see the contents of the disc clocking in at just under 40 megabytes. An intro movie and an outro movie account for 75% of that. Format ? None other than that curious ASCII anomaly, ARMovie/RPL with Escape 122 codec data.

  Cyclemania

  
  
  

  Cyclemania is one of those FMV backdrop action games, but with a motorcycle theme. I had a good feeling I would find some odd multimedia artifacts here and the game didn’t disappoint. The videos are apparently handled using 3-4 discrete files per animation. I’ve documented my cursory guesses and linked some samples at the new MultimediaWiki page.

  Interplay ACMP
  This is unrelated to this particular acquistion, but I was contacted today about audio files harvested from the 1993 DOS game Star Trek : Judgment Rites. The files begin with the ASCII signature "Interplay ACMP Data". This reminds me of Interplay MVE files which begin with the similar string "Interplay MVE File". My theory is that these files use the ACOMP compression format, though I’m still trying to make it fit.

  Wiki and samples are available as usual if you’d like to add your own research.

• Compiling FFMPEG on CentOS DigitalOcean

  29 juillet 2015, par coder_uk

  I set up a DigitalOcean instance running CentOS 6.5 and successfully followed the guide to compile FFMPEG (https://trac.ffmpeg.org/wiki/CompilationGuide/Centos). Hurrah !

  But of course I realised that by default, DigitalOcean creates a root user and so ffmpeg now lives in /root/bin/ffmpeg. Which isn’t ideal because when I want to exec the ffmpeg bin from nginx, I would have to run nginx as root for it to have permission.

  Questions ...

  1) Long-shot, but presumably if I change the owner of the ffmpeg binary to nginx, it still won’t work, because nginx won’t be able to access the /root folder it is in. Correct ?

  2) I could run nginx as root (’user root’). But this seems like a very bad idea. Correct ?

  3) Which leaves me with the option of creating a new user, and then compiling ffmpeg into its home folder. But : which user ? EC2 creates ’ec2-user’, so should I make my own equivalent for DO ? But then won’t I have to run nginx as that user, else I’ll run into the same problem ?

  Or should I compile ffmpeg into the ’nginx’ home folder, if indeed it has one ? Is that how it is supposed to be done ?

  Since compiling ffmpeg takes ages, I don’t want to keep doing it, and the static files all seem very out of date. Thanks

• How to track single-page websites and web applications using Piwik Analytics

  21 février 2017, par InnoCraft — Community, Development

  Single-page websites and web applications have become a standard over the last years. Getting the tracking of such websites and apps right is crucial to your success as you need to ensure the measured data is meaningful and correct. That’s why we, at InnoCraft, help our clients setting up their web tracking and measurement strategy. Some challenges our clients face are the tracking of single-page websites and web applications. We will cover this challenge in this post with a complete example at the bottom.

  Embedding the Tracking Code

  First you need to embed your JavaScript tracking code into your single-page website or web application as usual. To do this go to “Administration” in the top right in your Piwik, click on “Tracking Code” and adjust the tracking code to your needs.

  Tracking a New Page View

  The challenge begins when you need to track a new page view. A single-page app is different from a usual website as there is no regular new page load and Piwik cannot detect automatically when a new page is viewed. This means you need to let Piwik know whenever the URL and the page title changes. You can do this using the methods setCustomUrl and setDocumentTitle like this :

  window.addEventListener('hashchange', function() {
  
          _paq.push(['setCustomUrl', '/' + window.location.hash.substr(1)']);
  
          _paq.push(['setDocumentTitle', 'My New Title']);
  
          _paq.push(['trackPageView']);
  
  }

  Resetting previously set custom variables

  If you have set any Custom Variables in scope “page”, you need to make sure to delete these custom variables again as they would be attributed to the new page view as well otherwise. The following code requires Piwik 3.0.2 :

  _paq.push(['deleteCustomVariables', 'page']);      
  
  _paq.push(['trackPageView']);

  Updating the generation time

  Next you need to update the generation time before tracking a new page view. Otherwise, the initial page generation time will be attributed to all of your subsequent pageviews.

  If you don’t load new content from the server when the page changes, simply set the value to zero :

  _paq.push(['setGenerationTimeMs', 0]);
  
  _paq.push(['trackPageView']);

  In case you load new content from the server, we recommend to measure the time it took to load this content (in milliseconds) and set the needed time :

  _paq.push(['setGenerationTimeMs', timeItTookToLoadPage]);
  
  _paq.push(['trackPageView']);

  Updating the referrer

  Depending on whether you want to track the previous page as a referrer for the new page view, you should update the referrer URL by setting it to the previous page URL :

  _paq.push(['setReferrerUrl', previousPageUrl]);
  
  _paq.push(['trackPageView']);

  Making Piwik Aware of New Content

  When you show a new page, your single-page DOM might change as well. For example, you might replace parts of your page with new content that you loaded from your server via Ajax. This means you need to instruct Piwik to scan the DOM for new content. We’ll now go over various content types (Videos & Audio, Forms, Links and Downloads, Content tracking).

  Video and Audio tracking

  If you use the Media Analytics feature to track your videos and audios, whenever a new page is displayed you need to call the following method :

  _paq.push(['MediaAnalytics::scanForMedia', documentOrElement]);

  When you don’t pass any parameter, it will scan the entire DOM for new media. Alternatively, you can pass an element to scan only a certain area of your website or app for new media.

  Form tracking

  If you use the Form Analytics feature to measure the performance of your online forms, whenever a new page is displayed you need to call the following method :

  _paq.push(['FormAnalytics::scanForForms', docuemntOrElement]);

  Where documentOrElement points either to document to re-scan the entire DOM (the default when no parameter is set) or you can pass an element to restrict the re-scan to a specific area.

  Link tracking

  Supposing that you use the link tracking feature to measure outlinks and downloads, Piwik needs to re-scan the entire DOM for newly added links whenever your DOM changes. To make sure Piwik will track such links, call this method :

  _paq.push(['enableLinkTracking']);

  Content tracking

  If you use the Content Tracking feature, whenever a new page is displayed and some parts of your DOM changes, you need to call this method :

  _paq.push(['trackContentImpressionsWithinNode', documentOrElement]);

  Where documentOrElement points either to document or an element similar to the other methods. Piwik will then scan the page for newly added content blocks.

  Measuring Single-Page Apps : Complete Example

  In this example we show how everything works together assuming you want to track a new page whenever a hash changes :

  var currentUrl = location.href;
  
  window.addEventListener('hashchange', function() {
  
      _paq.push(['setReferrerUrl', currentUrl]);
  
       currentUrl = '' + window.location.hash.substr(1);
  
      _paq.push(['setCustomUrl', currentUrl]);
  
      _paq.push(['setDocumentTitle', 'My New Title']);
  
  
  
      // remove all previously assigned custom variables, requires Piwik 3.0.2
  
      _paq.push(['deleteCustomVariables', 'page']); 
  
      _paq.push(['setGenerationTimeMs', 0]);
  
      _paq.push(['trackPageView']);
  
      
  
      // make Piwik aware of newly added content
  
      var content = document.getElementById('content');
  
      _paq.push(['MediaAnalytics::scanForMedia', content]);
  
      _paq.push(['FormAnalytics::scanForForms', content]);
  
      _paq.push(['trackContentImpressionsWithinNode', content]);
  
      _paq.push(['enableLinkTracking']);
  
  });

  Questions ?

  If you have any questions or need help, please get in touch with us. You can find more information about the Piwik JavaScript tracker on the Piwik Developer Zone.