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  • Les tâches Cron régulières de la ferme

    1er décembre 2010, par

    La gestion de la ferme passe par l’exécution à intervalle régulier de plusieurs tâches répétitives dites Cron.
    Le super Cron (gestion_mutu_super_cron)
    Cette tâche, planifiée chaque minute, a pour simple effet d’appeler le Cron de l’ensemble des instances de la mutualisation régulièrement. Couplée avec un Cron système sur le site central de la mutualisation, cela permet de simplement générer des visites régulières sur les différents sites et éviter que les tâches des sites peu visités soient trop (...)

  • Other interesting software

    13 avril 2011, par

    We don’t claim to be the only ones doing what we do ... and especially not to assert claims to be the best either ... What we do, we just try to do it well and getting better ...
    The following list represents softwares that tend to be more or less as MediaSPIP or that MediaSPIP tries more or less to do the same, whatever ...
    We don’t know them, we didn’t try them, but you can take a peek.
    Videopress
    Website : http://videopress.com/
    License : GNU/GPL v2
    Source code : (...)

  • Encoding and processing into web-friendly formats

    13 avril 2011, par

    MediaSPIP automatically converts uploaded files to internet-compatible formats.
    Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
    Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
    Where possible, text is analyzed in order to retrieve the data needed for search engine detection, and then exported as a series of image files.
    All uploaded files are stored online in their original format, so you can (...)

Sur d’autres sites (8531)

  • Looking for video libraries for editing video on windwos/ios/azure service

    15 juillet 2015, par sanyam

    Which library would be a good bet in terms of ...
    1. Richness in features (I want to create a video from short clips and images with effects and filters). Think auto videos created from Google Photos.
    2. Extensibility - I would prefer using similar tech on IOS and Windows apps. Might have to offload some processing to a web service on Azure (windows or linux).
    3. Programmability - An API is preferred over command line as it gives more flexibility and better error handling.

    Given all these options, what is my best bet ? I’ve only looked at ffmpeg till now, is there a better alternative ?

  • Drawing text on video with avconv only at the start of the video

    21 juillet 2013, par Gael

    I want to embed the creation date of personnal videos, but only at their start (let say the 10 first seconds).

    I'm using the drawtext of avconv :

    avconv -i input.avi -vf
    "drawtext=fontcolor=white:fontsize=30:fontfile=/usr/share/fonts/truetype/ubuntu-font-family/Ubuntu-L.ttf:text='$date':x=30:y=h-text_h-30"
    test.mpg

    but I do not find any option to tell to just write the date on only a portion of the video. I could split the start of the video, or make an srt file, but there is probably an easier solution.

  • Seek function of HTML5 video and Maximum Keyframe Interval in video encoding compression

    20 décembre 2019, par Sanxofon

    This is a very specific question about how the seek function (of an HTML5 video element) interprets a video, in this case one in WEBM format and what specific relationship it has with the Maximum Keyframe Interval in the process of coding of said video.

    I’ve made this fiddle to show what I mean :

    https://jsfiddle.net/sanxofon/hctuxo3e/

    What it does : The idea is to control the position of a paused video with the scroll wheel of the mouse ... in addition, each frame of the video is copied to a canvas element, but I think that has no relation. I mention it just in case.

    What to watch : In Chrome (v66) and slightly less in Firefox (v59) the scrolling looks pretty good when the video is encoded with a Maximum Keyframe Interval of 6 or less, but jumps are appreciated when the interval is every 24 frames or more. This is noticeable in the video and even more on the canvas.

    FFMPEG : When encoding a video with FFMPEG this is achieved with the option -g6 or -g24 of Maximum Keyframe Interval. However, the file becomes heavier as we decrease the interval. It can be seen that there is no difference between both formats when the video is in play.

    You can switch the video in the snippet with the buttons.

    • Case 1 : When we use the video encoded with -g 6 the video scrolling is acceptable but the size increases : 6.229 Mb.

    FFMPEG string used :

     ffmpeg -i INPUT.MOV -c: v libvpx -qmin 0 -deadline best -qmax 50 -crf 1 -b: v 100K -g 6 test / video_g6.webm
    • Case 2 : When we use the video encoded with -g 24 the displacement is not smooth and suffers from jumps but the size decreases : 4,477 Mb.

    FFMPEG string used :

     ffmpeg -i INPUT.MOV -c: v libvpx -qmin 0 -deadline best -qmax 50 -crf 1 -b: v 100K -g 24 test / video_g24.webm

    Why does this happen ?

    What about -keyint_min or -force_key_frames ? Do they have any positive effect ? Is it better to use something like cgop (closed gop) ?

    I would appreciate some reference of consultation on this subject or a more or less detailed explanation of this relationship for both the WEBM container and for MP4 and OGG video.

    I am not looking so much for a magical ffmpeg chain (although I would appreciate it) but rather an explanation of how this relationship between the keyframes and the seek of a javascript video works.

    Thank you very much for reading here.

    P.S. One more thing, if the seek function only stops in a keyframe, is it possible that this frame has more quality than the others so that the quality increases when the video stops ?

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