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• Redux : how to add subtitles to mp4 using ffmpeg ?

  25 novembre 2015, par stachyra

  I have a tiny little example mp4 video (which unfortunately stack overflow won’t allow me to embed directly inside my question). Following the advice previously offered in this answer, I’d like to add a subtitle to the video, which will flash on the screen for 2 seconds, using an .srt file that looks like this :

  1
  
  00:00:02,000 --> 00:00:04,000
  
  Test subtitle

  As provided in the link above, I issue a command that looks like this :

  ffmpeg -i small.mp4 -f srt -i small.srt -c:v copy -c:a copy -c:s mov_text small_subtitles.mp4 >& err.log

  And the err.log file looks like this :

  ffmpeg version N-76950-g401c93d-tessus Copyright (c) 2000-2015 the FFmpeg developers
  
  built with Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn)
  
  configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --as=yasm --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzmq --enable-version3 --disable-ffplay --disable-indev=qtkit --disable-indev=x11grab_xcb
  
    libavutil      55.  7.100 / 55.  7.100
  
    libavcodec     57. 15.100 / 57. 15.100
  
    libavformat    57. 17.100 / 57. 17.100
  
    libavdevice    57.  0.100 / 57.  0.100
  
    libavfilter     6. 15.100 /  6. 15.100
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'small.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf56.40.101
  
    Duration: 00:00:10.02, start: 0.000000, bitrate: 23 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 188x112 [SAR 1:1 DAR 47:28], 17 kb/s, 60 fps, 60 tbr, 15360 tbn, 120 tbc (default)
  
  Metadata:
  
    handler_name    : VideoHandler
  
  Input #1, srt, from 'small.srt':
  
    Duration: N/A, bitrate: N/A
  
  Stream #1:0: Subtitle: subrip
  
  [mp4 @ 0x7f8492848000] Codec for stream 0 does not use global headers but container format requires global headers
  
  Output #0, mp4, to 'small_subtitles.mp4':
  
    Metadata:
  
  major_brand     : isom
  
  minor_version   : 512
  
  compatible_brands: isomiso2avc1mp41
  
  encoder         : Lavf57.17.100
  
  Stream #0:0(und): Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 188x112 [SAR 1:1 DAR 47:28], q=2-31, 17 kb/s, 60 fps, 60 tbr, 15360 tbn, 15360 tbc (default)
  
  Metadata:
  
    handler_name    : VideoHandler
  
  Stream #0:1: Subtitle: mov_text ([8][0][0][0] / 0x0008) (default)
  
  Metadata:
  
    encoder         : Lavc57.15.100 mov_text
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #1:0 -> #0:1 (subrip (srt) -> mov_text (native))
  
  Press [q] to stop, [?] for help
  
  frame=  601 fps=0.0 q=-1.0 Lsize=      29kB time=00:00:09.96 bitrate=  24.0kbits/s    
  
  video:21kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 39.561928%

  The resulting output, small_subtitles.mp4, does not seem to have the expected subtitle present.

  Furthermore, the error message,

  [mp4 @ 0x7f8492848000] Codec for stream 0 does not use global headers but container format requires global headers

  is highlighted in bold colors when I run this at the command line without capturing the err.log file (which makes me think it must be a significant message), although I am unable to reproduce that special print formatting easily here.

  I’ve also tried this method, but with the .avi replaced by .mp4, and it seems to just fail silently—no obvious error message, but also no subtitle in the resulting video either.

  Anybody have an idea how to fix this ? In particular, what does the business about global headers mean ?

  I’m working on OS X and am open to hearing answers that would use other open source tools as well.

• Your 6-step guide to increasing acquisition

  2 juillet 2019, par Matomo Core Team — Analytics Tips
  Your 6-step guide to increasing acquisition

  Want to save time and money, as well as increase conversions and acquisition ? Matomo Analytics is here to help with that !

  Let’s start by helping you create a website visitors’ acquisition strategy, without it you might be going in blind and missing opportunities that might’ve been easily found in your metrics.

  To help you craft a strategy for your site, check out the steps below !

  Step one : Get familiar with the Acquisition feature

  The easiest way is to start with Matomo’s Acquisition feature itself. Discover and take action on the marketing channels with the biggest ROI for your business. You’ll learn :

  How to get traffic from external websites : Find out who’s helping you succeed from external websites and convince them to do more of it. Get more traffic by proactively asking for : paid sponsorships ; guest blog posts ; or spending more advertising on the particular website.

  

  About Social Networks : Which social media channels are connecting with the audience you want ? Take the guesswork out by using only the ones you need. By finding out which social channels your ideal audience prefers, you can generate shareable, convincing and engaging content to drive shares and traffic through to your site.

  Campaigns : This helps you understand which marketing campaign is working and which isn’t. You can then shift your efforts to effectively gain more visitors with less costs. Keep track of every ad and content piece you show across internal and external channels to see which has the biggest impact on your business objectives.

  Enhanced SEO : Every acquisition plan needs a focus on maximising your Search Engine Optimization (SEO) efforts. When it comes to getting conclusive search engine referrer metrics, you need to be sure you’re getting ALL the insights to drive your SEO strategy. See keyword position rankings, integrate Google, Bing and Yahoo search consoles, and no longer be restricted with “keyword not defined” showing up in your keywords reports.

  >> Watch Acquisition introduction video (playtime : 2.54 minutes)

  Step two : Set your goals and monitor conversion funnels

  Let the Goals feature guide you

  Goals are essential for building your marketing strategy and getting new customers. The more goals you track, the more you learn about behavioural changes and modify pathways to impact acquisitions over time. 

  Are you checking :

  • Which channels are converting the best for your business ?
  • Which cities/countries are most popular ?
  • What devices will attract the most visitors ?
  • How engaged your visitors are before converting ?

  This way you can see if your campaigns (SEO, PPC, signups, blogs etc.) or optimising efforts (A/B Testing, Funnels) have made an impact with the time and investment you’ve put in.

  >> Watch Goals introduction video (playtime : 2.04 minutes)

  The Funnels feature leads you to success

  Conversion funnels give you the big picture on whether your acquisition plans are paying off and where they may be falling short. If the ultimate goal of your site is to drive conversions, then each funnel can tell you how effectively you’re driving traffic through to your desired outcome.

  >> Watch Funnels introduction video (playtime : 2.29 minutes)

  

  Step three : Measure the success of every touchpoint in your customer’s journey

  Multi Attribution feature

  Accurately identify channels where visitors first engage with your business, as well as the final channel they came from, before purchasing your product/service. This helps you make smarter decisions when determining acquisition spend to accurately calculate the Customer Acquisition Cost (CAC). Here you no longer falsely over-estimate investment in failing marketing channels.

  >> Watch Multi Attribution introduction video (playtime : 2.28 minutes)

  Step four : For ecommerce sites, understand who your customers are to increase sales

  Ecommerce feature to significantly increase $ potential

  If your website’s overall purpose is to generate revenue, the Ecommerce feature gives you comprehensive insights into your customer’s purchasing behaviours.

  This heavily reduces your risks when marketing products to potential customers as you’ll understand who to target, what to target them with and where further opportunities exist.

  >> Watch Ecommerce introduction video (playtime : 2.04 minutes)

  

  Step five : Make sure the forms on your website are easy to complete

  Form Analytics feature

  Once you get visitors through the funnel, the forms on your website are the final step to conversion and need special attention. If not done right, you could be missing out on converting a large portion of your visitors.

  Thankfully, you can now identify and fix pain points on the forms that are most important to your business’ success.

  >> Watch Form Analytics introduction video (playtime : 2.39 minutes)

  

  Step six : Discover what a customer journey looks like on a user-by-user basis and bring in key acquisition elements to your strategy

  Visitor Profiles tell you each visitors’ history

  The Profile feature summarises every visit, action and purchase made.

  Better understand :

  • Why your visitors viewed your website.
  • Why your returning visitors continue to view your website.
  • What specifically your visitors are looking for and whether they found it on your website.

  The benefit is being able to see how a combination of acquisition channels play a part in a single buyer’s journey.

  >> Watch Visitors introduction video (playtime : 1.46 minutes)

  

  To summarise

  This guide will set you on a path to creating a well-planned acquisition strategy. It’s the key to attracting and capturing the attention of potential visitors/leads, and successfully driving them through a funnel/buyer’s journey on your website.

  Because of Matomo’s reputation as a trusted analytics platform, the features above can be used to assist you in making smarter data-driven decisions. You can pursue different acquisition avenues with confidence and create a strategy that’s agile and ready for success, all while respecting user privacy.

• Different ways of embedding the Piwik tracking code for faster website performance

  18 avril 2017, par InnoCraft — Community, Development

  Many studies have shown that performance matters a lot. For each 100ms a websites takes longer to load, a business may lose about 0.1% to 1% in revenue. It also matters because Google judges page speed as a ranking factor for search results page. At InnoCraft, we help our clients optimizing their Piwik integration and recommend different ways of embedding the tracking code tailored to their needs. The best way to embed the tracking code depends on your website, what you want to achieve, and how important tracking is to you.

  This technical blog post mainly focuses on improving the time to load your website. This is an important metric as for example Google usually measures the time it took to load a page. Many businesses therefore want to get to the page load event as quickly as possible.

  The regular way of embedding the tracking code

  By default, Piwik is embedded in the header or footer of your website. This is a sensible default. While it is loaded asynchronously and deferred, it still does delay the onload event. Depending on the performance of your Piwik, how fast your website loads, how your website’s resources are embedded, and other factors you may want to consider alternatives. Three of them I will introduce below.

  Embedding the tracker after the load event

  To ensure that your website will always load even if the Piwik server is un-available, you may want to load the tracking code only after the website is loaded like this :

  var _paq = _paq || [];
  
  _paq.push(["trackPageView"]);
  
  _paq.push(["enableLinkTracking"]);
  
  
  
  function embedTrackingCode() {
  
     var u="https://your.piwik.domain/";
  
     _paq.push(["setTrackerUrl", u+"piwik.php"]);
  
     _paq.push(["setSiteId", "1"]);
  
  
  
     var d=document, g=d.createElement("script"), s=d.getElementsByTagName("script")[0]; g.type="text/javascript";
  
     g.defer=true; g.async=true; g.src=u+"piwik.js"; s.parentNode.insertBefore(g,s);    
  
  }
  
  
  
  if (window.addEventListener) { 
  
      window.addEventListener("load", embedTrackingCode, false); 
  
  } else if (window.attachEvent) { 
  
      window.attachEvent("onload",embedTrackingCode); 
  
  } else {
  
      embedTrackingCode();
  
  }

  The downside is you won’t track all of your visitors because some will have already left your website by the time your website is fully loaded. Especially when you have a JavaScript-heavy website or when your website takes longer to load in general. To detect the load event correctly cross browser, you may want to use a library like jQuery.

  Delaying the tracking

  Another technique is to load the tracking with a little delay at the end of your website like this :

  setTimeout(function () {
  
      embedTrackingCode();
  
  }, 5);

  This time the tracking script will still track most of your visitors but does not slow down loading the rest of your website as much as it would do by default (at least perceived). In some cases, you will notice a performance improvement when looking at the “time to load” but it depends on your website.

  Not loading the JavaScript Tracker at all

  With Piwik you also have the option to not embed the tracking code into your websites at all and instead generate reports from the webserver logs using Piwik Log Analytics. This works very well but some data might not be available like the device resolution which can be only captured using JavaScript. On the bright side this solution also captures users with ad blockers or tracking blockers.

  Questions ?

  We invite you to test different ways to see what makes sense for you and how it affects your website performance as well as the perceived performance. If you have any questions, feel free to get in touch with us.

  Read on

  The last post in this series is Performance optimizations you can apply today to load the Piwik JavaScript tracker faster.