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  • Keeping control of your media in your hands

    13 avril 2011, par

    The vocabulary used on this site and around MediaSPIP in general, aims to avoid reference to Web 2.0 and the companies that profit from media-sharing.
    While using MediaSPIP, you are invited to avoid using words like "Brand", "Cloud" and "Market".
    MediaSPIP is designed to facilitate the sharing of creative media online, while allowing authors to retain complete control of their work.
    MediaSPIP aims to be accessible to as many people as possible and development is based on expanding the (...)

  • Le plugin : Podcasts.

    14 juillet 2010, par

    Le problème du podcasting est à nouveau un problème révélateur de la normalisation des transports de données sur Internet.
    Deux formats intéressants existent : Celui développé par Apple, très axé sur l’utilisation d’iTunes dont la SPEC est ici ; Le format "Media RSS Module" qui est plus "libre" notamment soutenu par Yahoo et le logiciel Miro ;
    Types de fichiers supportés dans les flux
    Le format d’Apple n’autorise que les formats suivants dans ses flux : .mp3 audio/mpeg .m4a audio/x-m4a .mp4 (...)

  • Les images

    15 mai 2013

Sur d’autres sites (4714)

  • encode YUV420 frame to VP9

    21 novembre 2018, par User800222

    As title,

    I’m pulling frames from a IP camera. I converted the input raw data to YUV420 format, and would like to encode YUV420 to VP9, and save frames as .webm format. Would I be able to do that ? Or should I input a BGR444 format for encoding ?

    BTW, to set up the parameters for encoding vp9. Is the av_dict_set() the right function for setting parameters ?

    Ex : (http://wiki.webmproject.org/ffmpeg/vp9-encoding-guide)

    av_dict_set(&opt, "crf"    , "23", 0);
    
av_dict_set(&opt, "speed"  , "4" , 0);
    
av_dict_set(&opt, "threads", "8" , 0);
    
av_dict_set(&opt, "pass"   , "1" , 0);
    
av_dict_set(&opt, "b:v", "1400k", 0);

    Edit : The wiki uses 2 pass for setting parameters, would I be able to do in with 1 pass ?

    Edit2 : Blow code seems to be working, wonder how can I bring the size of the videos (vp9) down ? Currently, I have similar size as using h264 encoder.

        av_dict_set(&opt, "crf"    ,        "45", 0);  
    
    av_dict_set(&opt, "speed"  ,        "8" , 0); 
    
    av_dict_set(&opt, "quality",        "realtime", 0);
    
    av_dict_set(&opt, "threads",        "8" , 0);
    
    av_dict_set(&opt, "tile-columns",   "3", 0);
    
    av_dict_set(&opt, "frame-parallel", "1", 0);
    
    av_dict_set(&opt, "row-mt",         "1", 0);

    Update1 :
    YUV420P can be encoded as VP9 !

  • Create a looped video with countdown

    13 décembre 2016, par Enrico Deleo

    Something maybe challenging here :
    I want to stream (via rtmp) a video with a fixed image and a countdown applied on it. I know I can create a slideshow with even audio background with ffmtp (http://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images) but I’m wondering if I can loop it AND apply an overlay with the countdown to a given date.

    Any ideas ?

  • Is it possible to change volume with no reencode with ffmpeg ?

    30 juin 2023, par John Smith

    I just had this question because I used the following command with ffmpeg :

    



    ffmpeg -i input.wav -filter:a "volume=0.2" output.wav


    



    Following the documentation here : https://trac.ffmpeg.org/wiki/AudioVolume

    



    However, when I created the new file, the output was half the size of the input and the bitrate of the audio track was reduced as well.

    



    So my questions are :

    



      

    1. Is the bitrate supposed to decrease with decreasing and increasing volume like so ?

      2. 


    2. Is it possible to change volume without reencoding with ffmpeg ?

      3. 


    


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