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  • Contribute to documentation

    13 avril 2011

    Documentation is vital to the development of improved technical capabilities.
    MediaSPIP welcomes documentation by users as well as developers - including : critique of existing features and functions articles contributed by developers, administrators, content producers and editors screenshots to illustrate the above translations of existing documentation into other languages
    To contribute, register to the project users’ mailing (...)

  • MediaSPIP en mode privé (Intranet)

    17 septembre 2013, par

    À partir de la version 0.3, un canal de MediaSPIP peut devenir privé, bloqué à toute personne non identifiée grâce au plugin "Intranet/extranet".
    Le plugin Intranet/extranet, lorsqu’il est activé, permet de bloquer l’accès au canal à tout visiteur non identifié, l’empêchant d’accéder au contenu en le redirigeant systématiquement vers le formulaire d’identification.
    Ce système peut être particulièrement utile pour certaines utilisations comme : Atelier de travail avec des enfants dont le contenu ne doit pas (...)

  • Gestion des droits de création et d’édition des objets

    8 février 2011, par

    Par défaut, beaucoup de fonctionnalités sont limitées aux administrateurs mais restent configurables indépendamment pour modifier leur statut minimal d’utilisation notamment : la rédaction de contenus sur le site modifiables dans la gestion des templates de formulaires ; l’ajout de notes aux articles ; l’ajout de légendes et d’annotations sur les images ;

Sur d’autres sites (11784)

  • Theatrical quality ffmpeg/x264 encoding of a high-motion 1080p video

    2 décembre 2011, par Ian

    I've been struggling with encoding videos using FFMPEG and x264. The output stutters when played back in Quicktime, while in VLC it shows a lot of compression artifacts at the same places Quicktime stutters. So it seems like Quicktime is stuttering because it's trying to suppress the corruption/artifacts.

    The videos have a lot of random motion in them, including frames where 75% of the pixels will change at a random interval (the video is software generated so it's truly pseudo-random). The compression seems to be choking in these places where it's likely detecting a "scene cut" incorrectly. It also seems to choke at regular intervals where I guess it's doing a keyframe.

    I've based my encoding preset off of the x264-hq preset that comes with FFMPEG. I've tried turning off scene cut detection, and playing with the keyint/g and keyint_min options. Setting g to 1 makes it work, but blows out the filesize. I've tried the lossless presets, but they won't playback at all in Quicktime. Oddly, I haven't had any problems when working with a lower-resolution test video (1440x810).

    Here's the preset I have right now, which works, but yields a file that's approximately 60% larger than the (non-working) hq preset yields. Is there any way to improve upon this ? The filesize doesn't matter much, I just want something that will playback anywhere and be very high quality.

    coder=1
    flags=+loop
    cmp=+chroma
    partitions=+parti8x8+parti4x4+partp8x8+partp4x4+partb8x8
    me_method=umh
    subq=8
    me_range=16
    g=1
    keyint_min=1
    sc_threshold=0
    i_qfactor=0.71
    b_strategy=1crf=20
    qcomp=0.6
    qmin=20
    qmax=51
    qdiff=4
    bf=16
    refs=4
    trellis=1
    flags2=+dct8x8+wpred+bpyramid+mixed_refs
    wpredp=2
    

    Here's the command :

    ffmpeg \
      -r 60 -i "frame-%06d.tiff" \
      -vcodec libx264 -vpre my_preset \
      -threads 0 \
      -r 60 -an -f out.mp4
    
  • Theatrical quality ffmpeg/x264 encoding of a high-motion 1080p video

    2 décembre 2011, par Ian

    I've been struggling with encoding videos using FFMPEG and x264. The output stutters when played back in Quicktime, while in VLC it shows a lot of compression artifacts at the same places Quicktime stutters. So it seems like Quicktime is stuttering because it's trying to suppress the corruption/artifacts.

    The videos have a lot of random motion in them, including frames where 75% of the pixels will change at a random interval (the video is software generated so it's truly pseudo-random). The compression seems to be choking in these places where it's likely detecting a "scene cut" incorrectly. It also seems to choke at regular intervals where I guess it's doing a keyframe.

    I've based my encoding preset off of the x264-hq preset that comes with FFMPEG. I've tried turning off scene cut detection, and playing with the keyint/g and keyint_min options. Setting g to 1 makes it work, but blows out the filesize. I've tried the lossless presets, but they won't playback at all in Quicktime. Oddly, I haven't had any problems when working with a lower-resolution test video (1440x810).

    Here's the preset I have right now, which works, but yields a file that's approximately 60% larger than the (non-working) hq preset yields. Is there any way to improve upon this ? The filesize doesn't matter much, I just want something that will playback anywhere and be very high quality.

    coder=1
    flags=+loop
    cmp=+chroma
    partitions=+parti8x8+parti4x4+partp8x8+partp4x4+partb8x8
    me_method=umh
    subq=8
    me_range=16
    g=1
    keyint_min=1
    sc_threshold=0
    i_qfactor=0.71
    b_strategy=1crf=20
    qcomp=0.6
    qmin=20
    qmax=51
    qdiff=4
    bf=16
    refs=4
    trellis=1
    flags2=+dct8x8+wpred+bpyramid+mixed_refs
    wpredp=2
    

    Here's the command :

    ffmpeg \
      -r 60 -i "frame-%06d.tiff" \
      -vcodec libx264 -vpre my_preset \
      -threads 0 \
      -r 60 -an -f out.mp4
    
  • Silicon Graphics Motion Video Compressor 1 & 2 decoder

    17 décembre 2012, par Peter Ross
    Silicon Graphics Motion Video Compressor 1 & 2 decoder
    

    Signed-off-by : Vittorio Giovara <vittorio.giovara@gmail.com>

    • [DH] Changelog
    • [DH] doc/general.texi
    • [DH] libavcodec/Makefile
    • [DH] libavcodec/allcodecs.c
    • [DH] libavcodec/avcodec.h
    • [DH] libavcodec/codec_desc.c
    • [DH] libavcodec/mvcdec.c
    • [DH] libavcodec/version.h