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• How to encode a video from several images generated in a C++ program without writing the separate frame images to disk ?

  29 janvier 2016, par ksb496

  I am writing a C++ code where a sequence of N different frames is generated after performing some operations implemented therein. After each frame is completed, I write it on the disk as IMG_%d.png, and finally I encode them to a video through ffmpeg using the x264 codec.

  The summarized pseudocode of the main part of the program is the following one :

  std::vector<int> B(width*height*3);
  
  for (i=0; i/ void generateframe(std::vector<int> &amp;, int)
  
    generateframe(B, i); // Returns different images for different i values.
  
    sprintf(s, "IMG_%d.png", i+1);
  
    WriteToDisk(B, s); // void WriteToDisk(std::vector<int>, char[])
  
  }
  
  </int></int></int>

  The problem of this implementation is that the number of desired frames, N, is usually high (N 100000) as well as the resolution of the pictures (1920x1080), resulting into an overload of the disk, producing write cycles of dozens of GB after each execution.

  In order to avoid this, I have been trying to find documentation about parsing directly each image stored in the vector B to an encoder such as x264 (without having to write the intermediate image files to the disk). Albeit some interesting topics were found, none of them solved specifically what I exactly want to, as many of them concern the execution of the encoder with existing images files on the disk, whilst others provide solutions for other programming languages such as Python (here you can find a fully satisfactory solution for that platform).

  The pseudocode of what I would like to obtain is something similar to this :

  std::vector<int> B(width*height*3);
  
  video_file=open_video("Generated_Video.mp4", ...[encoder options]...);
  
  for (i=0; icode></int>

  According to what I have read on related topics, the x264 C++ API might be able to do this, but, as stated above, I did not find a satisfactory answer for my specific question. I tried learning and using directly the ffmpeg source code, but both its low ease of use and compilation issues forced me to discard this possibility as a mere non-professional programmer I am (I take it as just as a hobby and unluckily I cannot waste that many time learning something so demanding).

  Another possible solution that came to my mind is to find a way to call the ffmpeg binary file in the C++ code, and somehow manage to transfer the image data of each iteration (stored in B) to the encoder, letting the addition of each frame (that is, not "closing" the video file to write) until the last frame, so that more frames can be added until reaching the N-th one, where the video file will be "closed". In other words, call ffmpeg.exe through the C++ program to write the first frame to a video, but make the encoder "wait" for more frames. Then call again ffmpeg to add the second frame and make the encoder "wait" again for more frames, and so on until reaching the last frame, where the video will be finished. However, I do not know how to proceed or if it is actually possible.

  Edit 1 :

  As suggested in the replies, I have been documenting about named pipes and tried to use them in my code. First of all, it should be remarked that I am working with Cygwin, so my named pipes are created as they would be created under Linux. The modified pseudocode I used (including the corresponding system libraries) is the following one :

  FILE *fd;
  
  mkfifo("myfifo", 0666);
  
  
  
  for (i=0; i/ void WriteToPipe(std::vector<int>, FILE *&amp;fd)
  
    fflush(fd);
  
    fd=fclose("myfifo");
  
  }
  
  unlink("myfifo");
  
  </int>

  WriteToPipe is a slight modification of the previous WriteToFile function, where I made sure that the write buffer to send the image data is small enough to fit the pipe buffering limitations.

  Then I compile and write the following command in the Cygwin terminal :

  ./myprogram | ffmpeg -i pipe:myfifo -c:v libx264 -preset slow -crf 20 Video.mp4

  However, it remains stuck at the loop when i=0 at the "fopen" line (that is, the first fopen call). If I had not called ffmpeg it would be natural as the server (my program) would be waiting for a client program to connect to the "other side" of the pipe, but it is not the case. It looks like they cannot be connected through the pipe somehow, but I have not been able to find further documentation in order to overcome this issue. Any suggestion ?

• How to Split MP3 Files with FFmpeg ?

  27 octobre 2022, par Lucas

  How to split mp3 files with FFmpeg into the small mp3 files make it easy to manage, share and transfer ?
For example , I do have test.mp3 file with 1MB and I want to split into test00(i).mp3 files with smaller size.

  


  I've tried with windows tool but want to have script which is running with ffmpeg.

  


• 9 Ways to Customise Your Matomo Like a Pro

  5 octobre 2022, par Erin

  Matomo is a feature-rich web analytics platform. As such, it has many layers of depth — core features, extra plug-ins, custom dimensions, reports, extensions and integrations. 

  Most of the product elements you see can be personalised and customised to your needs with minimal restrictions. However, this breadth of choice can be overlooked by new users. 

  In this post, we explain how to get the most out of Matomo with custom reports, dashboards, dimensions and even app design. 

  How to customise your Matomo web analytics

  To make major changes to Matomo (e.g., create custom dashboards or install new plugins), you’ll have to be a Matomo Super User (a.k.a. The Admin). Super Users can also grant administrator permissions to others so that more people could customise your Matomo deployment. 

  Most feature-related customisations (e.g. configuring a custom report, adding custom goal tracking, etc.) can be done by all users. 

  With the above in mind, here’s how you can tweak Matomo to better serve your website analytics needs : 

  1. Custom dashboards

  

  Dashboards provide a panorama view of all the collected website statistics. We display different categories of stats and KPIs as separate widgets — a standalone module you can also customise. 

  On your dashboard, you can change the type, position and number of widgets on display. This is an easy way to create separate dashboard views for different projects, clients or team members. Rather than a one-size-fits-all dashboard, a custom dashboard designed for a specific role or business unit will increase data-driven decision-making and efficiency across the business.

  You can create a new dashboard view in a few clicks. Then select a preferred layout — a split-page view or multi columns. Next, populate the new dashboard area with preferred widgets showing :

  • SEO website rankings 
  • Visits, conversions and revenue 
  • Custom reports 

  Or code a custom widget area to pull specific website stats or other reporting data you need. Once you are done, arrange everything with our drag-and-drop functionality. 

  

  Popular feature use cases

  • Personalised website statistics layout for convenient viewing 
  • Simplified analytics dashboards for the line of business leaders/stakeholders 
  • Project- or client-specific dashboards for easy report sharing 

  Read more about customising Matomo dashboards and widget areas. 

  2. Custom reports

  

  As the name implies, Custom Reports widget allows you to mesh any of the dimensions and metrics collected by Matomo into a custom website traffic analysis. Custom reports save users time by providing specific data needed in one view so there is no need to jump back and forth between multiple reports or toggle through a report to find data.

  For each custom report, you can select up to three dimensions and then apply additional quantitative measurements (metrics) to drill down into the data.

  For example, if you want to closely observe mobile conversion rates in one market, you can create the following custom report :

  • Dimensions : User Type (registered), Device type (mobile), Location (France)
  • Metrics : Visits, Conversion Rate, Revenue, Avg. Generation Time.

  Custom Report widget is available within Matomo Cloud and as a plugin for Matomo On-Premise.

  &lt;script type=&quot;text/javascript&quot;&gt;<br />
       if ('function' === typeof window.playMatomoVideo){<br />
       window.playMatomoVideo(&quot;custom_reports&quot;, &quot;#custom_reports&quot;)<br />
       } else {<br />
       document.addEventListener(&quot;DOMContentLoaded&quot;, function() { window.playMatomoVideo(&quot;custom_reports&quot;, &quot;#custom_reports&quot;); });<br />
       }<br />
  &lt;/script&gt;

  Popular feature use cases

  • Campaign-specific reporting to better understand the impact of different promo strategies 
  • Advanced event tracking for conversion optimization 
  • Market segmentation reports to analyse different audience cohorts 

  Read more about creating and analysing Custom Reports.

  3. Custom widgets

  

  We realise that our users have different degrees of analytics knowledge. Some love in-depth reporting dimensions and multi-row reporting tables. Others just want to see essential stats. 

  To delight both the pros and the novice users, we’ve created widgets — reporting sub-modules you can add, delete or rearrange in a few clicks. Essentially, a widget is a slice of a dashboard area you can populate with extra information. 

  You can add pre-made custom widgets to Matomo or develop your own widget to display custom reports or even external data (e.g., offline sales volume). At the same time, you can also embed Matomo widgets into other applications (e.g., a website CMS or corporate portal).

  Popular feature use cases

  • Display main goals (e.g., new trial sign-ups) on the main dashboard for greater visibility 
  • Highlight cost-per-conversion reporting by combining goals and conversion data to keep your budgets in check 
  • Run omnichannel eCommerce analytics (with embedded offline sales data) to get a 360-degree view into your operations 

  Read more about creating widgets in Matomo (beginner’s guide). 

  4. Custom dimensions 

  

  Dimensions describe the characteristics of reported data. Think of them as “filters” — a means to organise website analytics data by a certain parameter such as “Browser”, “Country”, “Device Type”, “User Type” and many more. 

  Custom Dimensions come in handy for all sorts of segmentation reports. For example, comparing conversion rates between registered and guest users. Or tracking revenue by device type and location. 

  For convenience, we’ve grouped Custom Dimensions in two categories :

  Visit dimensions. These associate metadata about a user with Visitor profiles — a summary of different knowledge you have about your audience. Reports for Visit scoped custom dimensions are available in the Visitors section of your dashboard. 

  Action dimensions. These segment users by specific actions tracked by Matomo such as pageviews, events completion, downloads, form clicks, etc. When configuring Custom Dimensions, you can select among pre-defined action types or code extra action dimensions. Action scoped custom dimensions are available in the Behaviours section of Matomo. 

  Depending on your Matomo version, you can apply 5 – 15 custom dimensions to reports. 

  Important : Since you can’t delete dimensions (only deactivate them), think about your use case first. Custom Dimensions each have their own dedicated reports page on your Matomo dashboard. 

  Popular custom dimension use cases among users :

  • Segmenting reports by users’ screen resolution size to understand how your website performs on different devices
  • Monitor conversion rates for different page types to determine your best-performing assets 

  Read more about creating, tracking and managing Custom Dimensions. 

  5. Custom scheduled reports

  Manually sending reports can be time consuming, especially if you have multiple clients or provide reports to numerous stakeholders. Custom scheduled reports remove this manual process to improve efficiency and ensure timely distribution of data to relevant users.

  Any report in Matomo (default or custom) can be shared with others by email as a PDF file, HTML content or as an attached CSV document. 

  You can customise which data you want to send to different people — your colleagues, upper management, clients or other company divisions. Then set up the frequency of email dispatches and Matomo will do the rest. 

  Auto-scheduling an email report is easy. Name your report, select a Segment (aka custom or standard report), pick time, file format and sender. 

  

  You can also share links to Matomo reports as text messages, if you are using ASPSMS or Clockwork SMS. 

  Popular feature use cases

  • Convenient stakeholder reporting on key website KPIs 
  • Automated client updates to keep clients informed and reduce workload 
  • Easy data downloads for doing custom analysis with business intelligence tools 

  Read more about email reporting features in Matomo. 

  6. Custom alerts

  

  Custom Alerts is a Matomo plugin for keeping you updated on the most important analytics events. Unlike Custom Reports, which provide a complete or segmented analytics snapshot, alerts are better suited for tracking individual events. For example, significant traffic increases from a specific channel, new 404 pages or major goal achievement (e.g., hitting 1,000 sales in a week). 

  Custom Alerts are a convenient way to keep your finger on the pulse of your site so you can quickly remedy an issue or get updated on reaching a crucial KPI promptly. You can receive custom alerts via email or text message in a matter of minutes.

  To avoid flooding your inbox with alerts, we recommend reserving Custom Alerts for a select few use cases (3 to 5) and schedule custom Email Reports to receive general web page analytics. 

  Popular custom alerts use cases among users :

  • Monitor sudden drops in revenue to investigate the cause behind them and solve any issues promptly 
  • Get notified of traffic spikes or sudden dips to better manage your website’s technical performance 

  Read more about creating and managing Custom Alerts. 

  7. Goals

  

  Goals feature helps you better understand how your website performs on certain business objectives such as lead generation, online sales or content discovery. A goal is a quantifiable action you want to measure (e.g., a specific page visit, form submission or a file download). 

  When combined together, Goals make up your sales funnel — a series of specific actions you expect users to complete in order to convert. 

  Goals-setting and Funnel Analytics are a powerful, customisable combo for understanding how people navigate your website ; what makes them take action or, on the contrary, lose interest and bounce off. 

  On Matomo, you can simultaneously track multiple goals, monitor multiple conversions per one visit (e.g., when one user requests two content downloads) and assign revenue targets to specific goals.

  &lt;script type=&quot;text/javascript&quot;&gt;<br />
       if ('function' === typeof window.playMatomoVideo){<br />
       window.playMatomoVideo(&quot;goals&quot;, &quot;#goals&quot;)<br />
       } else {<br />
       document.addEventListener(&quot;DOMContentLoaded&quot;, function() { window.playMatomoVideo(&quot;goals&quot;, &quot;#goals&quot;); });<br />
       }<br />
  &lt;/script&gt;

  Separately, Matomo Cloud users also get access to a premium Funnels feature and Multi Channel Conversion Attribution. On-Premises Matomo users can get both as paid plugins via our Marketplace.

  Popular goal tracking use cases among users :

  • Tracking newsletter subscription to maximise subscriber growth 
  • Conversion tracking for gated content (e.g., eBooks) to understand how each asset performs 
  • Analysing the volume of job applications per post to better interpret your HR marketing performance 

  Read more about creating and managing Goals in Matomo.

  8. Themes

  

  Want to give your Matomo app a distinctive visual flair ? Pick a new free theme for your On-Premises installation. Minimalistic, dark or classic — our community created six different looks that other Matomo users can download and install in a few clicks. 

  If you have some HTML/CSS/JS knowledge, you can also design your own Matomo theme. Since Matomo is an open-source project, we don’t restrict interface customisation and always welcome creativity from our users.

  Read more about designing your own Matomo theme (developer documentation).

  9. White labelling

  

  Matomo is one of the few website analytics tools to support white labelling. White labelling means that you can distribute our product to others under your brand. 

  For example, as a web design agency, you can delight customers with pre-installed GDPR-friendly website analytics. Marketing services providers, in turn, can present their clients with embedded reporting widgets, robust funnel analytics and 100% unsampled data. 

  Apart from selecting a custom theme, you can also align Matomo with your brand by :

  • Customising product name
  • Using custom header/font colours 
  • Change your tracking endpoint
  • Remove links to Matomo.org

  To streamline Matomo customisation and set-up, we developed a White Label plug-in. It provides a convenient set of controls for changing your Matomo deployment and distributing access rights to other users or sharing embedded Matomo widgets). 

  Read more about white labelling Matomo. 

  Learning more about Matomo 

  Matomo has an ever-growing list of features, ranging from standard website tracking controls to unique conversion rate optimisation tools (heatmaps, media analytics, user cohorts and more).

  To learn more about Matomo features you can check our free video web analytics training series where we cover the basics. For feature-specific tips, tricks and configurations, browse our video content or written guides. 

  21 day free trial. No credit card required.