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  • Les vidéos

    21 avril 2011, par

    Comme les documents de type "audio", Mediaspip affiche dans la mesure du possible les vidéos grâce à la balise html5 .
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    Son avantage principal quant à lui est de bénéficier de la prise en charge native de vidéos dans les navigateur et donc de se passer de l’utilisation de Flash et (...)

  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

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Sur d’autres sites (3543)

  • Need Help. audio API choice

    6 mars 2017, par Wyatt

    What API can I use to determine a single digit representing an entire mp3’s average amplitude of a range of frequencies ? Ex) 100 Hz - 200 Hz should output a single digit, 5dB.

  • How Funnel for Piwik Analytics enriches your Piwik experience giving you ultimate insights and debugging capabilities

    13 janvier 2017, par InnoCraft — Community

    No matter what type of website or app you have, whether you are trying to get your users to sign up for something or sell products, there is a certain number of steps your visitors have to go through. On every step you lose visitors and therefore potential revenue and conversions. Therefore it is critical to know where your visitors actually follow those steps in your website or app, where you lose them and where your visitors maybe get confused. By defining a funnel, you can improve your conversion rates, sales and revenue as you can exactly determine where you lose your visitors in converting your goal or a sale.

    A Funnel defines a series of steps that you expect your visitors to take on their way to converting a goal. Funnels, a premium feature for Piwik developed by InnoCraft, lets you create funnels to get the data you need to improve your websites and mobile apps. Learn more about Funnel.

    In this blog post we will cover the reports the Funnel plugin provides. The next blog post shows you how to configure and validate your funnel in Piwik.

    Integration in Goal reports

    At Piwik and InnoCraft, we usually start looking into our goal reports. Funnel integrates directly into each goal reporting page giving you a quick overview how your funnel is doing. This saves us a lot of time as we don’t have to separately look into each funnel page and only takes us maybe an additional second to keep an eye on our funnels. By clicking on the headline or “View funnel report” link, you can directly go to the funnel report to get a more detailed report if you notice any spike in the evolution of the conversions or conversion rate.

    Getting an overall Funnel overview

    Next we usually go to the “Funnel Overview” page where it shows a list of all activated Funnels and their performance over time. You will find the look familiar as it is similar to the “Goals Overview” page. If we find something unusual there, for example any spikes, we usually directly click on the headline of the Funnel to go to the detailed Funnel report. You can also choose a funnel from the left reporting menu or search for a funnel by entering the shortcut “f”.

    Viewing a funnel report

    A funnel reporting page looks very similar to a Goal reporting page. It starts with an evolution graph and sparklines showing you the performance of your funnel over time.

    In the evolution graph you can select the metrics you want to plot. We usually have an eye on the funnel conversion rate and the number of “Funnel entries” or the number of “Funnel conversions”. The conversion rate alone does not show you how your funnel is performing. Imagine the rate is always stable at around 20% and you might think everything is alright, but if the number of visitors that take part in your funnel goes down, you might have a problem as the number of funnel conversions actually decreases even though the rate is the same. So we recommend to not only have a look at the conversion rate. The report will remember the metrics you want to plot each time you open it so you don’t have to re-select them over and over again.

    The funnel overview

    In the funnel overview we are giving you more details about the funnel and goal related conversion metrics so you don’t have to switch between the goal and funnel report and compare them easily.

    When you analyze a funnel report, you might not always remember how the funnel is configured. Even though you specify names for each step you sometimes need to know on which pages a certain step will be activated. By clicking on the funnel summary link you can quickly look into the funnel configuration and also see all important metrics at a glance in a simple table without having to scroll.

    You might also notice the Visitor Log link which will show you all actions for all visitors that have entered this funnel. This lets you really understand how your visitors navigate through your website and how they proceeded, exited or converted your funnel on a visitor level.

    The Funnel visualization

    Below the funnel overview you can visually see where your visitors entered, proceeded, converted and exited your funnel. We kept the UI clean so you can focus on the important things.

    Most tools only give you the pages where visitors have entered your funnel but we do better and also show you the list of external referrers used by visitors to enter your funnel directly (marketing campaigns, search engines or other websites). Also we do not only show only the top 5 pages but up to 100 pages and 50 referrers (more can be configured if needed). When you hover a row, you will not only see the number of hits but also the percentage each row has contributed to the entries. Here you want to look and understand how your visitors enter your funnel and based on the data maybe invest in successful referrers, campaigns and pages. If the pages or referrers you expect to see there don’t show up, your users might not understand the path you had in mind for them.

    Next you may notice how many visits have gone through each step, in this case 3487 visits. The green and red bar lets you quickly identify how many of your visitors have proceeded to the next step (green) compared to how many have exited the funnel at this step (red). Ideally, most of the bar is green and not red indicating that more visitors proceed to the next step than they exit.

    Now the next feature is really valuable. When you hover the step title or the number of visits, you will notice that two icons appear :

    Those two little icons are really powerful and give you even more insights to really dig into all the data. The left icon shows you the visitor log showing all actions of each visitor that have participated in this particular funnel step. This means for each step you get to see all the details and actions of each visitor. This lets you really debug and understand problems in your funnel.

    At InnoCraft, we understand that plain numbers are often not so valuable. Only the evolution over time, when you put the numbers in relation to something else you can really understand how your website is doing. The icon to the right lets you do exactly this, it lets you view the row evolution for each funnel step. We are sure you will enjoy this feature. It lets you explore how each funnel step is doing over time. For example the number of entries for a step or how many proceeded to the next step from here over time. Here you ideally want to see that the “Proceeded Rate” increases over time, meaning more and more visitors actually proceed to the next step instead of exiting it.

    We are sure you will really love those features that give you just those extra insights that other tools don’t give you.

    On the right you can find out where your visitors went to, if they did not proceed any further in the funnel. This lets you better understand why they left the funnel and did not proceed any further.

    At the end of the funnel report you find again the number of conversions and the conversion rate. Here we recommend looking into the visitor log when you hover the name of the last step as you can analyze how each visitor converted this funnel in detail.

    Applying segments

    Funnels lets you apply any Piwik segment to the Funnel report allowing you to dice your visitors multiplying the value you get out of Funnel. For example you may want to apply a segment and analyze the funnel for visitors that have visited your website or mobile app for the first time vs. recurring visitors. Sometimes it may be interesting how visitors from different countries go through your funnel, the possibilities are endless. We really recommend to take advantage of segments to understand your different target groups even better.

    The plugin also adds some new segments to your Piwik letting you segment any Piwik report by visitors that have participated in a funnel or participated in a particular funnel step. For example you could go to the “Visitors => Locations” report and apply a segment for your funnel to see which countries have participated or converted most in your funnel.

    Widgets, Scheduled Reports, and more.

    This is not where the fun ends. Funnels defines new widgets that you can add to your dashboard or export it into a third party website. You can set up scheduled reports to receive the Funnel report automatically via email or sms or download the report to share it with your colleagues. It works also very well with Custom Alerts and you can view the Funnel report in the Piwik Mobile app. You can manage Funnels via HTTP API and also fetch all Funnel reports via the HTTP Reporting API. The plugin is really nicely integrated into Piwik we will need some more blog posts to show you all the ways Funnels advances your Piwik experience and how it lets you dig into all the data so you can increase your conversions and sales based on this data.

    How to get Funnels and related features

    You can get Funnels on the Piwik Marketplace. If you want to learn more about Funnels you might be also interested in the Funnel User Guide and the Funnel FAQ.

    Similar to Funnels we also offer Users Flow which lets you visualize the flow of your users and visitors across several interactions.

  • Why does the frame count change when scaling with FFmpeg ?

    22 octobre 2016, par ajmicek

    I use this to scale 1920x1080 H.264 videos :

    ffmpeg -i IMG_1438.MOV -threads 2 -vf scale=-2:600 IMG_1438_scaledTo600.MOV

    And it works great ! But here is my question : most of the time, the frame rate stays exactly the same between the original file and the scaled file. For example :

    $ mediainfo -F IMG_1426.MOV | grep Frame\ rate
    Frame rate                               : 29.970
    Frame rate                               : 29.970 FPS
    Frame rate mode                          : VFR
    Frame rate mode                          : Variable
    Frame rate                               : 29.970
    Frame rate                               : 29.970 (29970/1000) FPS

    $ mediainfo -F IMG_1426_scaledTo600.MOV | grep Frame\ rate
    Frame rate                               : 29.970
    Frame rate                               : 29.970 FPS
    Frame rate mode                          : CFR
    Frame rate mode                          : Constant
    Frame rate                               : 29.970
    Frame rate                               : 29.970 (30000/1001) FPS

    But sometimes, the frame rate increases dramatically :

    $ mediainfo -F IMG_1438.MOV | grep Frame\ rate
    Frame rate                               : 25.044
    Frame rate                               : 25.044 FPS
    Frame rate mode                          : VFR
    Frame rate mode                          : Variable
    Frame rate                               : 25.044
    Frame rate                               : 25.044 FPS

    $ mediainfo -F IMG_1438_scaledTo600.MOV | grep Frame\ rate
    Frame rate                               : 120.000
    Frame rate                               : 120.000 FPS
    Frame rate mode                          : CFR
    Frame rate mode                          : Constant
    Frame rate                               : 120.000
    Frame rate                               : 120.000 FPS

    What should I know about FFmpeg or libx264 or libswscale that will help me understand why this happens ? (Hoping to hear from LordNeckbeard, in particular).

    mediainfo IMG_1438.MOV --Full outputs :

    General
    Count                                    : 327
    Count of stream of this kind             : 1
    Kind of stream                           : General
    Kind of stream                           : General
    Stream identifier                        : 0
    Count of video streams                   : 1
    Count of audio streams                   : 1
    OtherCount                               : 2
    Video_Format_List                        : AVC
    Video_Format_WithHint_List               : AVC
    Codecs Video                             : AVC
    Audio_Format_List                        : AAC
    Audio_Format_WithHint_List               : AAC
    Audio codecs                             : AAC LC
    Complete name                            : IMG_1438.MOV
    File name                                : IMG_1438
    File extension                           : MOV
    Format                                   : MPEG-4
    Format                                   : MPEG-4
    Format/Extensions usually used           : mp4 m4v m4a m4b m4p 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma f4v
    Commercial name                          : MPEG-4
    Format profile                           : QuickTime
    Internet media type                      : video/mp4
    Codec ID                                 : qt  
    Codec ID                                 : qt   0000.00 (qt  )
    Codec ID/Url                             : http://www.apple.com/quicktime/download/standalone.html
    CodecID_Version                          : 0000.00
    CodecID_Compatible                       : qt  
    Codec                                    : MPEG-4
    Codec                                    : MPEG-4
    Codec/Extensions usually used            : mp4 m4v m4a m4b m4p 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma f4v
    File size                                : 113990140
    File size                                : 109 MiB
    File size                                : 109 MiB
    File size                                : 109 MiB
    File size                                : 109 MiB
    File size                                : 108.7 MiB
    Duration                                 : 52268
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 00:00:52.268
    Duration                                 : 00:00:52:09
    Duration                                 : 00:00:52.268 (00:00:52:09)
    Overall bit rate                         : 17447026
    Overall bit rate                         : 17.4 Mb/s
    Frame rate                               : 25.044
    Frame rate                               : 25.044 FPS
    Frame count                              : 1309
    Stream size                              : 56670
    Stream size                              : 55.3 KiB (0%)
    Stream size                              : 55 KiB
    Stream size                              : 55 KiB
    Stream size                              : 55.3 KiB
    Stream size                              : 55.34 KiB
    Stream size                              : 55.3 KiB (0%)
    Proportion of this stream                : 0.00050
    HeaderSize                               : 28
    DataSize                                 : 113966271
    FooterSize                               : 23841
    IsStreamable                             : No
    Encoded date                             : UTC 2016-10-08 22:51:19
    Tagged date                              : UTC 2016-10-08 22:52:12
    File last modification date              : UTC 2016-10-08 22:51:19
    File last modification date (local)      : 2016-10-08 17:51:19
    Writing library                          : Apple QuickTime
    Writing library                          : Apple QuickTime
    Encoded_Library_Name                     : Apple QuickTime
    com.apple.quicktime.make                 : Apple
    com.apple.quicktime.model                : iPhone 5
    com.apple.quicktime.software             : 10.0.2
    com.apple.quicktime.creationdate         : 2016-10-08T17:51:19-0500

    Video
    Count                                    : 334
    Count of stream of this kind             : 1
    Kind of stream                           : Video
    Kind of stream                           : Video
    Stream identifier                        : 0
    StreamOrder                              : 0
    ID                                       : 1
    ID                                       : 1
    Format                                   : AVC
    Format/Info                              : Advanced Video Codec
    Format/Url                               : http://developers.videolan.org/x264.html
    Commercial name                          : AVC
    Format profile                           : High@L4.1
    Format settings                          : CABAC / 1 Ref Frames
    Format settings, CABAC                   : Yes
    Format settings, CABAC                   : Yes
    Format settings, ReFrames                : 1
    Format settings, ReFrames                : 1 frame
    Internet media type                      : video/H264
    Codec ID                                 : avc1
    Codec ID/Info                            : Advanced Video Coding
    Codec ID/Url                             : http://www.apple.com/quicktime/download/standalone.html
    Codec                                    : AVC
    Codec                                    : AVC
    Codec/Family                             : AVC
    Codec/Info                               : Advanced Video Codec
    Codec/Url                                : http://developers.videolan.org/x264.html
    Codec/CC                                 : avc1
    Codec profile                            : High@L4.1
    Codec settings                           : CABAC / 1 Ref Frames
    Codec settings, CABAC                    : Yes
    Codec_Settings_RefFrames                 : 1
    Duration                                 : 52268
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 00:00:52.268
    Duration                                 : 00:00:52:09
    Duration                                 : 00:00:52.268 (00:00:52:09)
    Bit rate                                 : 17375530
    Bit rate                                 : 17.4 Mb/s
    Width                                    : 1920
    Width                                    : 1 920 pixels
    Height                                   : 1080
    Height                                   : 1 080 pixels
    Stored_Height                            : 1088
    Sampled_Width                            : 1920
    Sampled_Height                           : 1080
    Pixel aspect ratio                       : 1.000
    Display aspect ratio                     : 1.778
    Display aspect ratio                     : 16:9
    Rotation                                 : 90.000
    Rotation                                 : 90°
    Frame rate mode                          : VFR
    Frame rate mode                          : Variable
    Frame rate                               : 25.044
    Frame rate                               : 25.044 FPS
    Minimum frame rate                       : 23.077
    Minimum frame rate                       : 23.077 FPS
    Maximum frame rate                       : 30.000
    Maximum frame rate                       : 30.000 FPS
    Frame count                              : 1309
    Resolution                               : 8
    Resolution                               : 8 bits
    Colorimetry                              : 4:2:0
    Color space                              : YUV
    Chroma subsampling                       : 4:2:0
    Chroma subsampling                       : 4:2:0
    Bit depth                                : 8
    Bit depth                                : 8 bits
    Scan type                                : Progressive
    Scan type                                : Progressive
    Interlacement                            : PPF
    Interlacement                            : Progressive
    Bits/(Pixel*Frame)                       : 0.335
    Stream size                              : 113523046
    Stream size                              : 108 MiB (100%)
    Stream size                              : 108 MiB
    Stream size                              : 108 MiB
    Stream size                              : 108 MiB
    Stream size                              : 108.3 MiB
    Stream size                              : 108 MiB (100%)
    Proportion of this stream                : 0.99590
    Title                                    : Core Media Video
    Encoded date                             : UTC 2016-10-08 22:51:19
    Tagged date                              : UTC 2016-10-08 22:52:12
    Color range                              : Limited
    colour_description_present               : Yes
    Color primaries                          : BT.709
    Transfer characteristics                 : BT.709
    Matrix coefficients                      : BT.709

    Audio
    Count                                    : 272
    Count of stream of this kind             : 1
    Kind of stream                           : Audio
    Kind of stream                           : Audio
    Stream identifier                        : 0
    StreamOrder                              : 1
    ID                                       : 2
    ID                                       : 2
    Format                                   : AAC
    Format/Info                              : Advanced Audio Codec
    Commercial name                          : AAC
    Format profile                           : LC
    Codec ID                                 : 40
    Codec                                    : AAC LC
    Codec                                    : AAC LC
    Codec/Family                             : AAC
    Codec/CC                                 : 40
    Duration                                 : 52268
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 00:00:52.268
    Duration                                 : 00:00:52:15
    Duration                                 : 00:00:52.268 (00:00:52:15)
    Source duration                          : 52338
    Source duration                          : 52 s 338 ms
    Source duration                          : 52 s 338 ms
    Source duration                          : 52 s 338 ms
    Source duration                          : 00:00:52.338
    Bit rate mode                            : CBR
    Bit rate mode                            : Constant
    Bit rate                                 : 64000
    Bit rate                                 : 64.0 kb/s
    Channel(s)                               : 1
    Channel(s)                               : 1 channel
    Channel positions                        : Front: C
    Channel positions                        : 1/0/0
    ChannelLayout                            : C
    Samples per frame                        : 1024
    Sampling rate                            : 44100
    Sampling rate                            : 44.1 kHz
    Samples count                            : 2305019
    Frame rate                               : 43.066
    Frame rate                               : 43.066 FPS (1024 spf)
    Frame count                              : 2251
    Source frame count                       : 2254
    Compression mode                         : Lossy
    Compression mode                         : Lossy
    Stream size                              : 410424
    Stream size                              : 401 KiB (0%)
    Stream size                              : 401 KiB
    Stream size                              : 401 KiB
    Stream size                              : 401 KiB
    Stream size                              : 400.8 KiB
    Stream size                              : 401 KiB (0%)
    Proportion of this stream                : 0.00360
    Source stream size                       : 410894
    Source stream size                       : 401 KiB (0%)
    Source stream size                       : 401 KiB
    Source stream size                       : 401 KiB
    Source stream size                       : 401 KiB
    Source stream size                       : 401.3 KiB
    Source stream size                       : 401 KiB (0%)
    Source_StreamSize_Proportion             : 0.00360
    Title                                    : Core Media Audio
    Encoded date                             : UTC 2016-10-08 22:51:19
    Tagged date                              : UTC 2016-10-08 22:52:12

    Other #1
    Count                                    : 112
    Count of stream of this kind             : 2
    Kind of stream                           : Other
    Kind of stream                           : Other
    Stream identifier                        : 0
    Stream identifier                        : 1
    Type                                     : meta
    Duration                                 : 52268
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 00:00:52.268
    Duration                                 : 00:00:52.268
    Frame count                              : 6
    Bit rate mode                            : VBR

    Other #2
    Count                                    : 112
    Count of stream of this kind             : 2
    Kind of stream                           : Other
    Kind of stream                           : Other
    Stream identifier                        : 1
    Stream identifier                        : 2
    Type                                     : meta
    Duration                                 : 52268
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 52 s 268 ms
    Duration                                 : 00:00:52.268
    Duration                                 : 00:00:52.268
    Frame count                              : 1
    Bit rate mode                            : CBR

    and ffprobe IMG_1438.MOV outputs :

    ffprobe version 3.1.3 Copyright (c) 2007-2016 the FFmpeg developers
     built with Apple LLVM version 7.3.0 (clang-703.0.31)
     configuration: --prefix=/usr/local/Cellar/ffmpeg/3.1.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --disable-lzma --enable-vda
     libavutil      55. 28.100 / 55. 28.100
     libavcodec     57. 48.101 / 57. 48.101
     libavformat    57. 41.100 / 57. 41.100
     libavdevice    57.  0.101 / 57.  0.101
     libavfilter     6. 47.100 /  6. 47.100
     libavresample   3.  0.  0 /  3.  0.  0
     libswscale      4.  1.100 /  4.  1.100
     libswresample   2.  1.100 /  2.  1.100
     libpostproc    54.  0.100 / 54.  0.100
    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'IMG_1438.MOV':
     Metadata:
       major_brand     : qt  
       minor_version   : 0
       compatible_brands: qt  
       creation_time   : 2016-10-08 22:51:19
       com.apple.quicktime.make: Apple
       com.apple.quicktime.model: iPhone 5
       com.apple.quicktime.software: 10.0.2
       com.apple.quicktime.creationdate: 2016-10-08T17:51:19-0500
     Duration: 00:00:52.27, start: 0.000000, bitrate: 17446 kb/s
       Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 17375 kb/s, 25.04 fps, 120 tbr, 600 tbn, 1200 tbc (default)
       Metadata:
         rotate          : 90
         creation_time   : 2016-10-08 22:51:19
         handler_name    : Core Media Data Handler
         encoder         : H.264
       Side data:
         displaymatrix: rotation of -90.00 degrees
       Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 62 kb/s (default)
       Metadata:
         creation_time   : 2016-10-08 22:51:19
         handler_name    : Core Media Data Handler
       Stream #0:2(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
       Metadata:
         creation_time   : 2016-10-08 22:51:19
         handler_name    : Core Media Data Handler
       Stream #0:3(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
       Metadata:
         creation_time   : 2016-10-08 22:51:19
         handler_name    : Core Media Data Handler
    Unsupported codec with id 0 for input stream 2
    Unsupported codec with id 0 for input stream 3

    UPDATE
    To clarify : my video above, the one with the high framerate (120 FPS) output after scaling, plays perfectly before and after scaling with FFmpeg (no sync issues, and 120 FPS is only about 14% larger in file size), I am simply trying to understand why this increase in framerate happens (just a little beyond Mulvya’s note that the framerate stored in the container is wrong).

    From a programming perspective, the initial issue I ran into was that I was using frame= from FFmpeg’s sterr console output to determine progress, which reports erroneous results when the frame count increases dramatically on output ("I’m 372% done encoding ?!") ; I have since read another stackoverflow answer and changed my code to use time=, which appears to be a more robust way for me to display FFmpeg progress. (Also, there is FFmpeg’s -progress option, of course).

    Improving on the original command

    My new command to scale, preserve a useful framerate, and optimize threads :

    ffmpeg -i IMG_1438.MOV -vf scale=-2:600 -r 30 -vsync 0 IMG_1438_scaledTo600.MOV

    Where 30 is the "Maximum frame rate" from mediainfo.

    Thanks to help in the comments, I now know I do not fully understand FFmpeg’s use of three different time bases for timestamps : tbn, tbc, and tbr.
    They were explained by Robert Swain in 2009 and his explanation was also used to answer a Stackoverflow question about tbn, tbc, tbr.

    It sounds to me, as I’m pulling together comments from Mulvya below and Michael Rampe at another forum, that tbr is guessed ; it is frequently but not always the best value to use when changing from a variable to a constant frame rate video.

    Which leaves these 2 questions...

    (1) tbr is incorrect when "field rate and frame rate" differ ? Does this happen a lot ?
    (2) Is -r 30 where 30 is the maximum frame rate reported by mediainfo the best way to do it for most codec/container combinations ? (Or should I only use this method when I am scaling a H.264/MPEG-4 AVC video ?)