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  • Personnaliser les catégories

    21 juin 2013, par

    Formulaire de création d’une catégorie
    Pour ceux qui connaissent bien SPIP, une catégorie peut être assimilée à une rubrique.
    Dans le cas d’un document de type catégorie, les champs proposés par défaut sont : Texte
    On peut modifier ce formulaire dans la partie :
    Administration > Configuration des masques de formulaire.
    Dans le cas d’un document de type média, les champs non affichés par défaut sont : Descriptif rapide
    Par ailleurs, c’est dans cette partie configuration qu’on peut indiquer le (...)

  • Les statuts des instances de mutualisation

    13 mars 2010, par

    Pour des raisons de compatibilité générale du plugin de gestion de mutualisations avec les fonctions originales de SPIP, les statuts des instances sont les mêmes que pour tout autre objets (articles...), seuls leurs noms dans l’interface change quelque peu.
    Les différents statuts possibles sont : prepa (demandé) qui correspond à une instance demandée par un utilisateur. Si le site a déjà été créé par le passé, il est passé en mode désactivé. publie (validé) qui correspond à une instance validée par un (...)

  • 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 (...)

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  • How to convert VP8 track with different frame resolution to h264

    13 septembre 2016, par Nikita

    I have a .webm file with VP8 track, recorded from WebRTC stream by external service (TokBox Archiving). The stream is adaptive, so each frame in track could have different resolution. Most players (in webkit browsers) use video resolution from track description (which is always 640x480) and scale frames to this resolution. Firefox and VLC player uses real frame resolution, changing video resolution respectively.

    I want to achieve 2 goals :

    1. play this video in Internet Explorer 9+ without additional plugin installation.
    2. change frames resolution to one fixed resolution, so the video will look identically in different browsers.

    So, my plan is :

    • extract frames from source webm file to images with real frame resolution (e.g. PNG or BMP) (how could I do that ?)
    • find max width and max height of images
    • add black padding to images, so smaller frames will be in the center of a new frame (of size MAX_WIDHTxMAX_HEIGHT)
    • combine images to h264 track using ffmpeg

    Is all correct ? How can I achieve this ? Can this algorithm be optimized some way ?

    I tried ffmpeg to extract images, but it does not parse real frame resolution, using resolution from track header.
    I think some libwebm functions can help me (to parse frame headers and extract images). Maybe someone has some code snippets to do this ?

    Example .webm (download source, do not play google-converted version) : https://drive.google.com/file/d/0BwFZRvYNn9CKcndhMzlVa0psX00/view?usp=sharing

    Official description of adaptive stream from TokBox support : https://support.tokbox.com/hc/en-us/community/posts/206241666-Archived-video-resolution-is-supposed-to-be-720x1280-but-reports-as-640x480

  • Can x264 be used from Java code via JNI to decrease the resolution of RTMP streams ? [on hold]

    5 septembre 2016, par Orr151

    I would like to implement a custom RTMP transcoder to HLS format in Java. As the repackaging itself seems to be relatively clear and doable in Java, then I found the modification of the video resolution a bit challenging in Java. My plan is to avoid using existing solutions like FFmpeg or at least minimize the amount of 3rd party frameworks/tools integrated with my component.

    After some research it seems that reusage of JCodec and Xuggler can be challenging as both project are idle for a while. Also I’m not sure if their performance is acceptable. That’s why I would like to integrate directly with x264 library via JNI from Java code.

    Is integration with x264/libx264 from Java code to decrease resolution/bitrate doable and is it a good idea ? Could you please suggest any other solutions ?

    Thanks !

  • Can x264 be used from Java code via JNI to decrease the resolution of RTMP streams ? [on hold]

    5 septembre 2016, par Orr151

    I would like to implement a custom RTMP transcoder to HLS format in Java. As the repackaging itself seems to be relatively clear and doable in Java, then I found the modification of the video resolution a bit challenging in Java. My plan is to avoid using existing solutions like FFmpeg or at least minimize the amount of 3rd party frameworks/tools integrated with my component.

    After some research it seems that reusage of JCodec and Xuggler can be challenging as both project are idle for a while. Also I’m not sure if their performance is acceptable. That’s why I would like to integrate directly with x264 library via JNI from Java code.

    Is integration with x264/libx264 from Java code to decrease resolution/bitrate doable and is it a good idea ? Could you please suggest any other solutions ?

    Thanks !

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