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Autres articles (97)

  • MediaSPIP 0.1 Beta version

    25 avril 2011, par

    MediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
    The zip file provided here only contains the sources of MediaSPIP in its standalone version.
    To get a working installation, you must manually install all-software dependencies on the server.
    If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...)

  • Des sites réalisés avec MediaSPIP

    2 mai 2011, par

    Cette page présente quelques-uns des sites fonctionnant sous MediaSPIP.
    Vous pouvez bien entendu ajouter le votre grâce au formulaire en bas de page.

  • 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 (...)

Sur d’autres sites (13334)

  • lavc : drop encode() support for video.

    23 février 2012, par Anton Khirnov

    lavc : drop encode() support for video.

  • 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