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  • Publier sur MédiaSpip

    13 juin 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

  • Les formats acceptés

    28 janvier 2010, par

    Les commandes suivantes permettent d’avoir des informations sur les formats et codecs gérés par l’installation local de ffmpeg :
    ffmpeg -codecs ffmpeg -formats
    Les format videos acceptés en entrée
    Cette liste est non exhaustive, elle met en exergue les principaux formats utilisés : h264 : H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 m4v : raw MPEG-4 video format flv : Flash Video (FLV) / Sorenson Spark / Sorenson H.263 Theora wmv :
    Les formats vidéos de sortie possibles
    Dans un premier temps on (...)

  • List of compatible distributions

    26 avril 2011, par

    The table below is the list of Linux distributions compatible with the automated installation script of MediaSPIP. Distribution nameVersion nameVersion number Debian Squeeze 6.x.x Debian Weezy 7.x.x Debian Jessie 8.x.x Ubuntu The Precise Pangolin 12.04 LTS Ubuntu The Trusty Tahr 14.04
    If you want to help us improve this list, you can provide us access to a machine whose distribution is not mentioned above or send the necessary fixes to add (...)

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  • Marketing Cohort Analysis : How To Do It (With Examples)

    12 janvier 2024, par Erin

    The better you understand your customers, the more effective your marketing will become. 

    The good news is you don’t need to run expensive focus groups to learn much about how your customers behave. Instead, you can run a marketing cohort analysis using data from your website analytics.

    A marketing cohort groups your users by certain traits and allows you to drill down to discover why they take the actions on your website they do. 

    In this article, we’ll explain what a marketing cohort analysis is, show you what you can achieve with this analytical technique and provide a step-by-step guide to pulling it off. 

    What is cohort analysis in marketing ?

    A marketing cohort analysis is a form of behavioural analytics where you analyse the behavioural patterns of users who share a similar trait to better understand their actions. 

    These shared traits could be anything like the date they signed up for your product, users who bought your service through a paid ad or email subscribers from the United Kingdom.

    It’s a fantastic way to improve your marketing efforts, allowing you to better understand complex user behaviours, personalise campaigns accordingly and improve your ROI. 

    You can run marketing analysis using an analytics platform like Google Analytics or Matomo. With these platforms, you can measure how cohorts perform using traffic, engagement and conversion metrics.

    An example of marketing cohort chart

    There are two types of cohort analysis : acquisition-based cohort analysis and behavioural-based cohort analysis.

    Acquisition-based cohort analysis

    An acquisition-based cohort divides users by the date they purchased your product or service and tracks their behaviour afterward. 

    For example, one cohort could be all the users who signed up for your product in November. Another could be the users who signed up for your product in October. 

    You could then run a cohort analysis to see how the behaviour of the two cohorts differed. 

    Did the November cohort show higher engagement rates, increased frequency of visits post-acquisition or quicker conversions compared to the October cohort ? Analysing these cohorts can help with refining marketing strategies, optimising user experiences and improving retention and conversion rates.

    As you can see from the example, acquisition-based cohorts are a great way to track the initial acquisition and how user behaviour evolves post-acquisition.

    Behavioural-based cohort analysis

    A behavioural-based cohort divides users by their actions on your site. That could be their bounce rate, the number of actions they took on your site, their average time on site and more.

    View of returning visitors cohort report in Matomo dashboard

    Behavioural cohort analysis gives you a much deeper understanding of user behaviour and how they interact with your website.

    What can you achieve with a marketing cohort analysis ?

    A marketing cohort analysis is a valuable tool that can help marketers and product teams achieve the following goals :

    Understand which customers churn and why

    Acquisition and behavioural cohort analyses help marketing teams understand when and why customers leave. This is one of the most common goals of a marketing cohort analysis. 

    Learn which customers are most valuable

    Want to find out which channels create the most valuable customers or what actions customers take that increase their loyalty ? You can use a cohort analysis to do just that. 

    For example, you may find out you retain users who signed up via direct traffic better than those that signed up from an ad campaign. 

    Discover how to improve your product

    You can even use cohort analysis to identify opportunities to improve your website and track the impact of your changes. For example, you could see how visitor behaviour changes after a website refresh or whether visitors who take a certain action make more purchases. 

    Find out how to improve your marketing campaign

    A marketing cohort analysis makes it easy to find out which campaigns generate the best and most profitable customers. For example, you can run a cohort analysis to determine which channel (PPC ads, organic search, social media, etc.) generates customers with the lowest churn rate. 

    If a certain ad campaign generates the low-churn customers, you can allocate a budget accordingly. Alternatively, if customers from another ad campaign churn quickly, you can look into why that may be the case and optimise your campaigns to improve them. 

    Measure the impact of changes

    You can use a behavioural cohort analysis to understand what impact changes to your website or product have on active users. 

    If you introduced a pricing page to your website, for instance, you could analyse the behaviour of visitors who interacted with that page compared to those who didn’t, using behavioural cohort analysis to gauge the impact of these website changes on engagemen or conversions.

    The problem with cohort analysis in Google Analytics

    Google Analytics is often the first platform marketers turn to when they want to run a cohort analysis. While it’s a free solution, it’s not the most accurate or easy to use and users often encounter various issues

    For starters, Google Analytics can’t process user visitor data if they reject cookies. This can lead to an inaccurate view of traffic and compromise the reliability of your insights.

    In addition, GA is also known for sampling data, meaning it provides a subset rather than the complete dataset. Without the complete view of your website’s performance, you might make the wrong decisions, leading to less effective campaigns, missed opportunities and difficulties in reaching marketing goals.

    How to analyse cohorts with Matomo

    Luckily, there is an alternative to Google Analytics. 

    As the leading open-source web analytics solution, Matomo offers a robust option for cohort analysis. With its 100% accurate data, thanks to the absence of sampling, and its privacy-friendly tracking, users can rely on the data without resorting to guesswork. It is a premium feature included with our Matomo Cloud or available to purchase on the Matomo Marketplace for Matomo On-Premise users.

    Below, we’ll show how you can run a marketing cohort analysis using Matomo.

    Set a goal

    Setting a goal is the first step in running a cohort analysis with any platform. Define what you want to achieve from your analysis and choose the metrics you want to measure. 

    For example, you may want to improve your customer retention rate over the first 90 days. 

    Define cohorts

    Next, create cohorts by defining segmentation criteria. As we’ve discussed above, this could be acquisition-based or behavioural. 

    Matomo makes it easy to define cohorts and create charts. 

    In the sidebar menu, click Visitors > Cohorts. You’ll immediately see Matomo’s standard cohort report (something like the one below).

    Marketing cohort by bounce rate of visitors in Matomo dashboard

    In the example above, we’ve created cohorts by bounce rate. 

    You can view cohorts by weekly, monthly or yearly periods using the date selector and change the metric using the dropdown. Other metrics you can analyse cohorts by include :

    • Unique visitors
    • Return visitors
    • Conversion rates
    • Revenue
    • Actions per visit

    Change the data selection to create your desired cohort, and Matomo will automatically generate the report. 

    Try Matomo for Free

    Get the web insights you need, without compromising data accuracy.

    No credit card required

    Analyse your cohort chart

    Cohort charts can be intimidating initially, but they are pretty easy to understand and packed with insights. 

    Here’s an example of an acquisition-based cohort chart from Matomo looking at the percentage of returning visitors :

    An Image of a marketing cohort chart in Matomo Analytics

    Cohorts run vertically. The oldest cohort (visitors between February 13 – 19) is at the top of the chart, with the newest cohort (April 17 – 23) at the bottom. 

    The period of time runs horizontally — daily in this case. The cells show the corresponding value for the metric we’re plotting (the percentage of returning visitors). 

    For example, 98.69% of visitors who landed on your site between February 13 – 19, returned two weeks later. 

    Usually, running one cohort analysis isn’t enough to identify a problem or find a solution. That’s why comparing several cohort analyses or digging deeper using segmentation is important.

    Segment your cohort chart

    Matomo lets you dig deeper by segmenting each cohort to examine their behaviour’s specifics. You can do this from the cohort report by clicking the segmented visitor log icon in the relevant row.

    Segmented visit log in Matomo cohort report
    Segmented cohort visitor log in Matomo

    Segmenting cohorts lets you understand why users behave the way they do. For example, suppose you find that users you purchased on Black Friday don’t return to your site often. In that case, you may want to rethink your offers for next year to target an audience with potentially better customer lifetime value. 

    Start using Matomo for marketing cohort analysis

    A marketing cohort analysis can teach you a lot about your customers and the health of your business. But you need the right tools to succeed. 

    Matomo provides an effective and privacy-first way to run your analysis. You can create custom customer segments based on almost anything, from demographics and geography to referral sources and user behaviour. 

    Our custom cohort analysis reports and colour-coded visualisations make it easy to analyse cohorts and spot patterns. Best of all, the data is 100% accurate. Unlike other web analytics solution or cohort analysis tools, we don’t sample data. 

    Find out how you can use Matomo to run marketing cohort analysis by trialling us free for 21 days. No credit card required.

  • Long Overdue MediaWiki Upgrade

    5 février 2014, par Multimedia Mike — General

    What do I do ? What I do ? This library book is 42 years overdue !
    I admit that it’s mine, yet I can’t pay the fine,
    Should I turn it in or should I hide it again ?
    What do I do ? What do I do ?

    I internalized the forgoing paean to the perils of procrastination by Shel Silverstein in my formative years. It’s probably why I’ve never paid a single cent in late fees in my entire life.

    However, I have been woefully negligent as the steward of the MediaWiki software that drives the world famous MultimediaWiki, the internet’s central repository of obscure technical knowledge related to multimedia. It is currently running of version 1.6 software. The latest version is 1.22.

    The Story So Far
    According to my records, I first set up the wiki late in 2005. I don’t know which MediaWiki release I was using at the time. I probably conducted a few upgrades in the early days, but that went by the wayside perhaps in 2007. My web host stopped allowing shell access and the MediaWiki upgrade process pretty much requires running a PHP script from a command line. Upgrade time came around and I put off the project. Weeks turned into months turned into years until, according to some notes, the wiki abruptly stopped working in July, 2011. Suddenly, there were PHP errors about “Namespace” being a reserved word.

    While I finally laid out a plan to upgrade the wiki after all these years, I eventually found that the problem had been caused when my webhost upgraded from PHP 5.2 -> 5.3. I also learned of a small number of code changes that caused the problem to go away, thus kicking the can down the road once more.

    Then a new problem showed up last week. I think it might be related to a new version of PHP again. This time, a few other things on my site broke, and I learned that my webhost now allows me to select a PHP version to use (with the version then set to “auto”, which didn’t yield much information). Rolling back to an earlier version of PHP might have solved the problem easily.

    But NO ! I made the determination that this goes no further. I want this wiki upgraded.

    The Arduous Upgrade Path
    There are 2 general upgrade paths I can think of :

    1. Upgrade in place on the server
    2. Upgrade offline and put the site back on the server

    Approach #1 is problematic since I don’t have direct shell access, though I considered using something like PHP Shell. Approach #2 involves getting the entire set of wiki files and a backup of the MySQL tables. This is workable since I keep automated backups of these items anyway.

    In fairly short order, I was able to set up a working copy of the MultimediaWiki hosted on a local Linux machine. Now what’s the move ? The MediaWiki software I’m running is 1.6.10. The very latest, as of this upgrade project is 1.22.2. I suppose it’s way too much to hope that the software will upgrade cleanly from 1.6.x straight to 1.22.x, but I guess it’s worth a shot…

    HA ! No chance. Okay, next idea is to march through the various versions and upgrade each in turn. MediaWiki has all their historic releases online, all the way back to the 1.3 lineage. I decided that the latest of each lineage should upgrade cleanly from anything in the previous version of lineage. E.g., 1.6.10 should upgrade cleanly to 1.7.3 (last in the 1.7 series). This seemed to be a workable strategy. So I downloaded the latest of each series, unpacked, and copied all the wiki files over the working installation and ran ‘php update.php’ in the maintenance/ directory.

    The process is tedious and not without its obstacles. I consider this penance for my years of wiki neglect. First, I run into the “PHP Parse error : syntax error, unexpected T_NAMESPACE, expecting T_STRING” issue, the same that I saw years ago after the webhost transitioned from PHP 5.2 -> 5.3. I could solve this by editing assorted files and changing “Namespace” -> “MWNamespace” (which is what MediaWiki did by version 1.13). But I would prefer not to.

    Instead, I downloaded the source for PHP 5.2 and compiled it in a separate directory, then called ‘/path/to/php/5.2/bin/php update.php’. Problem solved.

    The next problem is that a bunch of the database update scripts are specifying “Type=InnoDB”. This isn’t supported by modern MySQL databases. Now, it’s “Engine=InnoDB”. A quick search & replace at the command line fixes this for 1.6.x… and 1.7.x… and 1.8 through 1.12. Finally, at 1.13, it was no longer necessary. As a bonus, at 1.13, I was able to test the installation since Namespace had been renamed to MWNamespace. I would later learn that the table type modifications probably could have been simplified in by changing “$wgDBmysql4 = true ;” to “$wgDBmysql5 = true ;” somewhere in LocalSettings.php.

    Command line upgrading worked smoothly up through 1.18 series when I got a new syntax error :

    <br />
    PHP Fatal error:  Call to a member function addMessages() on a non-object in /mnt/sdb1/archive/wiki/extensions/Cite.php on line 68<br />

    Best I could do was comment out that line. I hope that doesn’t break anything important.

    In the home stretch, the very last transition (1.21 -> 1.22) failed :

    PHP Fatal error :  Cannot redeclare wfProfileIn() (previously declared in 
    /mnt/sdb1/archive/wiki/includes/profiler/Profiler.php:33) in 
    /mnt/sdb1/archive/wiki/includes/ProfilerStub.php on line 25
    

    Apparently, this problem arises occasionally since 1.18. I found a way around it thanks to this page : Deleted the file StartProfiler.php. Who am I to argue ?

    Upon completing the transition to 1.22, the wiki doesn’t look correct– the pictures aren’t showing up. The solution was to fix the temporary directory via LocalSettings.php.

    Back To Production
    Okay, it all works again ! Locally, that is. How to get it back to the server ? My first idea was that, knowing that this upgrade process can succeed, try stepping through the upgrade process again, but tell the update.php scripts to access the database tables on multimedia.cx. This seemed to be working for awhile, even though the database update phase often took 4-5 minutes. However, the transition from 1.8.5 -> 1.9.6 took 75 minutes and then timed out. According to my notes, “This isn’t going to work.”

    The new process :

    1. Dump the database tables from the local database.
    2. Create a new database remotely (melanson_wiki_ng).
    3. Dump the database table into melanson_wiki_ng.
    4. Move the index.php file out of the wiki files directory temporarily (or rename).
    5. Modify the LocalSettings.php to talk to the new database.
    6. Perform a lftp mirror operation in order to send all the files up to the server.
    7. Send the index.php file and hope beyond hope that everything magically works.

    And that’s the story of how the updated MultimediaWiki came back online. Despite the database dump file being over 110 MB, it only tool MySQL 1m45s to transmit it all to the remote server (let’s hear it for the ‘–compress’ option). For comparison, inserting the tables back into a fresh local database took 1m07s.

    When the MultimediaWiki was first live again, it loaded, but ever so slowly. This is when I finally looked into optimization and found that I was lacking any caching. So as a bonus, the MultimediaWiki should be much faster now.

    Going Forward
    For all I know, I did everything described here in the hardest way possible. But at least I got it done. Unless I learn of a better process, future upgrades will probably look similar to this.

    Additionally, I should probably take some time to figure out what new features are part of the standard MediaWiki distribution nowadays.

  • Winamp and the March of GUI

    1er juillet 2012, par Multimedia Mike — General, ars technica, gui, user interface, winamp

    Ars Technica recently published a 15-year retrospective on the venerable Winamp multimedia player, prompting bouts of nostalgia and revelations of "Huh ? That program is still around ?" from many readers. I was among them.



    I remember first using Winamp in 1997. I remember finding a few of these new files called MP3s online and being able to play the first 20 seconds using the official Fraunhofer Windows player— full playback required the fully licensed version. Then I searched for another player and came up with Winamp. The first version I ever used was v1.05 in the summer of 1997. I remember checking the website often for updates and trying out every single one. I can’t imagine doing that nowadays— programs need to auto-update themselves (which Winamp probably does now ; I can’t recall the last time I used the program).

    Video Underdog
    The last time Winamp came up on my radar was early in 2003 when a new version came with support for a custom, proprietary multimedia audio/video format called Nullsoft Video (NSV). I remember the timeframe because the date is indicated in the earliest revision of my NSV spec document (back when I was maintaining such docs in a series of plaintext files). This was cobbled together from details I and others in the open source multimedia community sorted out from sample files. It was missing quite a few details, though.

    Then, Winamp founder Justin Frankel — introduced through a colleague on the xine team — emailed me his official NSV format and told me I was free to incorporate details into my document just as long as it wasn’t obvious that I had the official spec. This put me in an obnoxious position of trying to incorporate details which would have been very difficult to reverse engineer without the official doc. I think I coped with the situation by never really getting around to updating my doc in any meaningful way. Then, one day, the official spec was released to the world anyway, and it is now mirrored here at multimedia.cx.

    I don’t think the format ever really caught on in any meaningful way, so not a big deal. (Anytime I say that about a format, I always learn it saw huge adoption is some small but vocal community.)

    What’s Wrong With This Picture ?
    What I really wanted to discuss in this post was the matter of graphical user interfaces and how they have changed in the last 15 years.

    I still remember when I first downloaded Winamp v1.05 and tried it on my Windows machine at the time. Indignantly, the first thought I had was, "What makes this program think it’s so special that it’s allowed to violate the user interface conventions put forth by the rest of the desktop ?" All of the Windows programs followed a standard set of user interface patterns and had a consistent look and feel... and then Winamp came along and felt it could violate all those conventions.

    I guess I let the program get away with it because it was either that or only play 20-second clips from the unregistered Fraunhofer player. Though incredibly sterile by comparison, the Fraunhofer player, it should be noted, followed Windows UI guidelines to the letter.

    As the summer of 1997 progressed and more Winamp versions were released, eventually one came out (I think it was v1.6 or so) that supported skins. I was excited because there was a skin that made the program look like a proper Windows program— at least if you used the default Windows color scheme, and had all of your fonts a certain type and size.

    Skins were implemented by packaging together a set of BMP images to overlay on various UI elements. I immediately saw a number of shortcomings with this skinning approach. A big one was UI lock-in. Ironically, if you skin an app and wish to maintain backwards compatibility with the thousands of skins selflessly authored by your vibrant community (seriously, I couldn’t believe how prolific these things were), then you were effectively locked into the primary UI. Forget about adding a new button anywhere.

    Another big problem was resolution-independence. Basing your UI on static bitmaps doesn’t scale well with various resolutions. Winamp had its normal mode and it also had double-sized mode.

    Skins proliferated among many types of programs in the late 1990s. I always treasured this Suck.com (remember them ? that’s a whole other nostalgia trip) essay from April, 2000 entitled Skin Cancer. Still, Winamp was basically the standard, and the best, and I put away my righteous nerd rage and even dug through the vast troves of skins. I remember settling on Swankamp for a good part of 1998, probably due to the neo-swing revival at the time.



    Then again, if Winamp irked me, imagine my reaction when I was first exposed to the Sonique Music Player in 1998 :



    The New UI Order
    Upon reflection, I realize now that I had a really myopic view of what a computer GUI should be. I thought the GUIs were necessarily supposed to follow the WIMP (windows, icons, mouse, pointer) paradigm and couldn’t conceive of anything different. For a long time, I couldn’t envision a useful GUI on a small device (like a phone) because WIMP didn’t fit well on such a small interface (even though I saw various ill-fated attempts to make it work). This thinking seriously crippled me when I was trying to craft a GUI for a custom console media player I was developing as a hobby many years ago.

    I’m looking around at what I have open on my Windows 7 desktop right now. Google Chrome browser, Apple iTunes, Adobe Photoshop Elements, and VMware Player are 4 programs which all seem to have their own skins. Maybe Winamp doesn’t look so out of place these days.