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  • How to measure the performance of a newsletter (or any email) with Piwik

    19 décembre 2017, par InnoCraft — Community

    To be able to grow your business, it is crucial to track all your marketing efforts. This includes all newsletters and emails that you share with people outside of your business. Otherwise, you won’t be able to know which of your daily efforts are yielding results.

    Are you wondering if it is possible to track the performance of an emailing campaign in Piwik efficiently ? Would you like to know if it is technically easy ? No worries, here is a “How to” tutorial showing you how easily you can track an emailing in Piwik properly.

    Different tracking levels for different needs

    There are many things that you may be interested to track, for example :

    1. How many users opened your email
    2. How many users interacted with the links in your email
    3. How many users interacted on your website through your email

    Let’s have a look at each of these levels.

    Step 1 – Tracking email and newsletter openings in Piwik

    Tracking email openings requires to add an HTML code to your newsletter. It works through what we call a tracking pixel, a tiny image of 1×1 that is transparent so the user will not be able to see it.
    In order to install it, here is an example of what this code looks like :

    <img src="https://piwik.example.com/piwik.php?idsite=YOUR_PIWIK_WEBSITE_ID&rec=1&bots=1&url=https%3A%2F%2Fexample.com%2Femail-opened%2Fnewsletter_XYZ&action_name=Email%20opened&_rcn=internal%20email%20name&_rck=newsletter_XYZ" style="border:0;” alt="" />

    The Piwik tracking pixel explained

    The above URL is composed of the following URL parameters which are part of our Tracking API :

    • idsite : Corresponds to the ID of the website you would like to track.
    • rec : You need to have rec=1 in order for the request to be actually recorded.
    • bots : Set it to 1 to include all the connections made to this request, bots included.
    • url : corresponds to the URL you would like to display in Piwik every time the email is opened.
    • action_name : This is the page name you would like to be tracked when the email is opened.
    • _rcn : The name you would like to give to your campaign.
    • _rck : The keyword you may like to use in order to summarize the content of your newsletter.

    You may have noticed some special characters here such as “%20”, “%2F”. That’s because the URL is encoded. We strongly recommend you to do so in order for your tracking not to break. Many tools are available on the web in order to encode your URLs such as https://www.urlencoder.org/.

    If you would like to access the previous tracking code easily, keep in mind that you can always find the tracking code generator within the “Piwik admin panel → Tracking code” :

    You can find more information about it on our guide at : How do I track how many users open and read my newsletter emails (using a pixel / beacon) ?

    As a result, the information will be pushed as following for any user who opens your email :

    To not bias your regular page views on your website with newsletter openings, we recommend tracking newsletter openings into a new website.

    Tracking even more data : the user ID example

    You can go deeper in your URL tracking by inserting other parameters such as the user id if you have this information within your emailing database. One of the main benefit of tracking the User ID is to connect data across multiple devices and browsers for a given user.

    You only need to add the following parameter &uid=XXX where XXX equals the dynamic value of the user ID :

    Make sure that UID from your emailing provider is the same as the one used on your website in order for your data to be consistent.

    Important note : some email providers are loading email messages by default which results in an opening even if the user did not actually open the email.

    Step 2 – Measure the clicks within your emailing

    Tracking clicks within an email lets you know with which content readers interacted the most. We recommend tracking all links in all your emails as a campaign, whether it is a newsletter, a custom support email, an email invoice, etc. You might be surprised to see which of your emails lead to conversions and if they don’t, try to tweak those emails, so they might in the future.

    Tracking clicks This works thanks to URL campaign tracking. In order to perform this action, you will need to add Piwik URL parameters to all your existing link URLs :

    • Website URL : for example “www.your-website.com”.
    • Campaign name : for example “pk_campaign=emailing”. Represents the name you would like to give to your campaign.
    • Campaign keyword : for example “pk_keyword=name-of-your-article”. Represents the name you would like to give to your content.
    • Campaign source : for example “pk_source=newsletter”. Represents the name of the referrer.
    • Campaign medium : for example “pk_medium=email”. Represents the type of referrer you are using.
    • Campaign content : for example “pk_content=title”. Represents the type of content.

    You can find more information about campaign url tracking in our “Tracking marketing campaigns with Piwik” guide.

    Here is a sample showing you how you can differentiate some links in a newsletter, all pointing to the same URL :

    Once you have added these URL parameters to each of your link, Piwik will clearly indicate the referrer of this specific campaign when a user clicks on a link in the newsletter and visits your website.

    Important note : if you do not track your campaigns, it will result in a bad interpretation of your data within Piwik as you will get webmail services or direct entries as referrer instead of your newsletter campaign.

    Step 3 – Measure emailing performances on your website

    Thanks to Piwik URL campaign parameters, you can now clearly identify the traffic brought through your emailing. You can now specifically isolate users who come from emails by creating a segment :

    Once done, you can either have a look at each user specifically through the visitor log report or analyze it as a whole within the rest of the reports.

    You can even measure your return on investment directly if goals have been defined. In order to know more about how to track goals within Piwik.

    Did you like this article ?

    If you enjoyed reading this article, do not hesitate to share it around you. Moreover, if there are any topics you would like to write us about in particular, just drop us an email and we will be more than happy to write about it.

  • (Solved) ffmpeg conversion increase bitrate

    9 novembre 2017, par user3386373

    When extracting Audio streams using ffmpeg from containers such as MP4, how does ffmpeg increase bitrate, if it is higher than the source bitrate ?

    An example might be ffmpeg -i video.mp4 -f mp3 -ab 256000 -vn music.mp3. What does ffmpeg do if the incoming bitrate is 128k ? Does it interpolate or default to 128k on the output music.mp3 ? I know this seems like not a so-called "programming question" but ffmpeg forum says it is going out of business and no one will reply to posts there.

  • Decoding VP8 On A Sega Dreamcast

    20 février 2011, par Multimedia Mike — Sega Dreamcast, VP8

    I got Google’s libvpx VP8 codec library to compile and run on the Sega Dreamcast with its Hitachi/Renesas SH-4 200 MHz CPU. So give Google/On2 their due credit for writing portable software. I’m not sure how best to illustrate this so please accept this still photo depicting my testbench Dreamcast console driving video to my monitor :



    Why ? Because I wanted to try my hand at porting some existing software to this console and because I tend to be most comfortable working with assorted multimedia software components. This seemed like it would be a good exercise.

    You may have observed that the video is blue. Shortest, simplest answer : Pure laziness. Short, technical answer : Path of least resistance for getting through this exercise. Longer answer follows.

    Update : I did eventually realize that the Dreamcast can work with YUV textures. Read more in my followup post.

    Process and Pitfalls
    libvpx comes with a number of little utilities including decode_to_md5.c. The first order of business was porting over enough source files to make the VP8 decoder compile along with the MD5 testbench utility.

    Again, I used the KallistiOS (KOS) console RTOS (aside : I’m still working to get modern Linux kernels compiled for the Dreamcast). I started by configuring and compiling libvpx on a regular desktop Linux system. From there, I was able to modify a number of configuration options to make the build more amenable to the embedded RTOS.

    I had to create a few shim header files that mapped various functions related to threading and synchronization to their KOS equivalents. For example, KOS has a threading library cleverly named kthreads which is mostly compatible with the more common pthread library functions. KOS apparently also predates stdint.h, so I had to contrive a file with those basic types.

    So I got everything compiled and then uploaded the binary along with a small VP8 IVF test vector. Imagine my surprise when an MD5 sum came out of the serial console. Further, visualize my utter speechlessness when I noticed that the MD5 sum matched what my desktop platform produced. It worked !

    Almost. When I tried to decode all frames in a test vector, the program would invariably crash. The problem was that the file that manages motion compensation (reconinter.c) needs to define MUST_BE_ALIGNED which compiles byte-wise block copy functions. This is necessary for CPUs like the SH-4 which can’t load unaligned data. Apparently, even ARM CPUs these days can handle unaligned memory accesses which is why this isn’t a configure-time option.

    Showing The Work
    I completed the first testbench application which ran the MD5 test on all 17 official IVF test vectors. The SH-4/Dreamcast version aces the whole suite.

    However, this is a video game console, so I had better be able to show the decoded video. The Dreamcast is strictly RGB— forget about displaying YUV data directly. I could take the performance hit to convert YUV -> RGB. Or, I could just display the intensity information (Y plane) rendered on a random color scale (I chose blue) on an RGB565 texture (the DC’s graphics hardware can also do paletted textures but those need to be rearranged/twiddled/swizzled).

    Results
    So, can the Dreamcast decode VP8 video in realtime ? Sure ! Well, I really need to qualify. In the test depicted in the picture, it seems to be realtime (though I wasn’t enforcing proper frame timings, just decoding and displaying as quickly as possible). Obviously, I wasn’t bothering to properly convert YUV -> RGB. Plus, that Big Buck Bunny test vector clip is only 176x144. Obviously, no audio decoding either.

    So, realtime playback, with a little fine print.

    On the plus side, it’s trivial to get the Dreamcast video hardware to upscale that little blue image to fullscreen.

    I was able to tally the total milliseconds’ worth of wall clock time required to decode the 17 VP8 test vectors. As you can probably work out from this list, when I try to play a 320x240 video, things start to break down.

    1. Processed 29 176x144 frames in 987 milliseconds.
    2. Processed 49 176x144 frames in 1809 milliseconds.
    3. Processed 49 176x144 frames in 704 milliseconds.
    4. Processed 29 176x144 frames in 255 milliseconds.
    5. Processed 49 176x144 frames in 339 milliseconds.
    6. Processed 48 175x143 frames in 2446 milliseconds.
    7. Processed 29 176x144 frames in 432 milliseconds.
    8. Processed 2 1432x888 frames in 2060 milliseconds.
    9. Processed 49 176x144 frames in 1884 milliseconds.
    10. Processed 57 320x240 frames in 5792 milliseconds.
    11. Processed 29 176x144 frames in 989 milliseconds.
    12. Processed 29 176x144 frames in 740 milliseconds.
    13. Processed 29 176x144 frames in 839 milliseconds.
    14. Processed 49 175x143 frames in 2849 milliseconds.
    15. Processed 260 320x240 frames in 29719 milliseconds.
    16. Processed 29 176x144 frames in 962 milliseconds.
    17. Processed 29 176x144 frames in 933 milliseconds.