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  • La sauvegarde automatique de canaux SPIP

    1er avril 2010, par

    Dans le cadre de la mise en place d’une plateforme ouverte, il est important pour les hébergeurs de pouvoir disposer de sauvegardes assez régulières pour parer à tout problème éventuel.
    Pour réaliser cette tâche on se base sur deux plugins SPIP : Saveauto qui permet une sauvegarde régulière de la base de donnée sous la forme d’un dump mysql (utilisable dans phpmyadmin) mes_fichiers_2 qui permet de réaliser une archive au format zip des données importantes du site (les documents, les éléments (...)

  • HTML5 audio and video support

    13 avril 2011, par

    MediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
    The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
    For older browsers the Flowplayer flash fallback is used.
    MediaSPIP allows for media playback on major mobile platforms with the above (...)

  • De l’upload à la vidéo finale [version standalone]

    31 janvier 2010, par

    Le chemin d’un document audio ou vidéo dans SPIPMotion est divisé en trois étapes distinctes.
    Upload et récupération d’informations de la vidéo source
    Dans un premier temps, il est nécessaire de créer un article SPIP et de lui joindre le document vidéo "source".
    Au moment où ce document est joint à l’article, deux actions supplémentaires au comportement normal sont exécutées : La récupération des informations techniques des flux audio et video du fichier ; La génération d’une vignette : extraction d’une (...)

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  • Encode h264 to match existing stream

    6 juin 2013, par Diego Sánchez

    In short : I have to encode a tiny amount of video frames and stitch them in front of a much bigger h.264 stream without reencoding said stream.

    The details : I receive a multi GB transport stream containing a h.264 es and an audio es. Currently the h.264 streams are always generated using x264, and I can assume this will be the case in the future. Now I have to prepend some video frames to this stream, but am not allowed to decode/encode the whole stream ; which leaves me with the only option to find out the exact parameters I need to pass x264_encoder_open so both streams match.

    Currently what I'm doing is :

    1. Demux the original ts and extract h.264 NAL packets.
    2. When I find the first "user data unregistered" SEI packet, I parse it and find a bunch of x264 parameters.
    3. Use libavcodec to start decoding the video. That gives me the dimensions of the picture and the h264 profile and level in the AVCodecContext structure.
    4. Match all of that as best as I can in the x264_param_t structure.

    I can do some encoding with that, and the encoded video plays correctly up to the join point. When VLC is reaching the stitch point it starts throwing out the following sequence of messages and soon after stops playing :

    [h264 @ 0x7fe36cd75be0] decode_slice_header error
    
[h264 @ 0x7fe36cd75be0] no frame!
    
[h264 @ 0x7fe36ccc9080] Width/height changing with threads is not implemented. Update your Libav version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.

    which clearly shows that my encoded frames do not match the original ones. I've been browsing the source code and can't seem to find a way of doing this. What I have currently (besides not working), involves a lot of guesswork, so even if I could make it work with the handful of example files I have, I would be scared to deploy this in production servers.

    So the obvious question is : Is there a safe, formal way of doing this ?

    Thanks in Advance

  • Encode h264 to match existing stream

    6 juin 2013, par Diego Sánchez

    In short : I have to encode a tiny amount of video frames and stitch them in front of a much bigger h.264 stream without reencoding said stream.

    The details : I receive a multi GB transport stream containing a h.264 es and an audio es. Currently the h.264 streams are always generated using x264, and I can assume this will be the case in the future. Now I have to prepend some video frames to this stream, but am not allowed to decode/encode the whole stream ; which leaves me with the only option to find out the exact parameters I need to pass x264_encoder_open so both streams match.

    Currently what I'm doing is :

    1. Demux the original ts and extract h.264 NAL packets.
    2. When I find the first "user data unregistered" SEI packet, I parse it and find a bunch of x264 parameters.
    3. Use libavcodec to start decoding the video. That gives me the dimensions of the picture and the h264 profile and level in the AVCodecContext structure.
    4. Match all of that as best as I can in the x264_param_t structure.

    I can do some encoding with that, and the encoded video plays correctly up to the join point. When VLC is reaching the stitch point it starts throwing out the following sequence of messages and soon after stops playing :

    [h264 @ 0x7fe36cd75be0] decode_slice_header error
    
[h264 @ 0x7fe36cd75be0] no frame!
    
[h264 @ 0x7fe36ccc9080] Width/height changing with threads is not implemented. Update your Libav version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.

    which clearly shows that my encoded frames do not match the original ones. I've been browsing the source code and can't seem to find a way of doing this. What I have currently (besides not working), involves a lot of guesswork, so even if I could make it work with the handful of example files I have, I would be scared to deploy this in production servers.

    So the obvious question is : Is there a safe, formal way of doing this ?

    Thanks in Advance

  • Revision 610e258cc5 : Make the round() replacement match C99 and POSIX. http://pubs.opengroup.org/onl

    8 août 2015, par Alex Converse

    Changed Paths :
     Modify /vp9/common/vp9_systemdependent.h



    Make the round() replacement match C99 and POSIX.

    http://pubs.opengroup.org/onlinepubs/009695399/functions/round.html

    Change-Id : Idf387d944d36bf593f8797db9053e11e5c9b9b39

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