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Médias (29)

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Autres articles (25)

  • 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 (...)

  • Support de tous types de médias

    10 avril 2011

    Contrairement à beaucoup de logiciels et autres plate-formes modernes de partage de documents, MediaSPIP a l’ambition de gérer un maximum de formats de documents différents qu’ils soient de type : images (png, gif, jpg, bmp et autres...) ; audio (MP3, Ogg, Wav et autres...) ; vidéo (Avi, MP4, Ogv, mpg, mov, wmv et autres...) ; contenu textuel, code ou autres (open office, microsoft office (tableur, présentation), web (html, css), LaTeX, Google Earth) (...)

  • List of compatible distributions

    26 avril 2011, par

    The table below is the list of Linux distributions compatible with the automated installation script of MediaSPIP. Distribution nameVersion nameVersion number Debian Squeeze 6.x.x Debian Weezy 7.x.x Debian Jessie 8.x.x Ubuntu The Precise Pangolin 12.04 LTS Ubuntu The Trusty Tahr 14.04
    If you want to help us improve this list, you can provide us access to a machine whose distribution is not mentioned above or send the necessary fixes to add (...)

Sur d’autres sites (6475)

  • H264 encoder settings

    30 novembre 2011, par Chris Robinson

    I'm using xuggler to encode a series of images to an MP4 file. I use the following code to setup the IStreamCoder and specify the H264 codec :

    // only set if codec is H264
    Configuration.configure("/usr/local/xuggler/share/ffmpeg/libx264-hq.ffpreset",
               outStreamCoder);

    outStreamCoder.setNumPicturesInGroupOfPictures(12);
    outStreamCoder.setCodec(codec);
    outStreamCoder.setBitRate(videoSettings.getBitrate());
    outStreamCoder.setBitRateTolerance(videoSettings.getBitrateTolerance());
    outStreamCoder.setPixelType(IPixelFormat.Type.YUV420P);
    outStreamCoder.setHeight(videoSettings.getResolution().height);
    outStreamCoder.setWidth(videoSettings.getResolution().width);
    outStreamCoder.setFlag(IStreamCoder.Flags.FLAG_QSCALE, true);
    outStreamCoder.setGlobalQuality(0);
    fps = IRational.make((int) videoSettings.getFramerate(), 1);
    outStreamCoder.setFrameRate(fps);
    outStreamCoder.setTimeBase(IRational.make(fps.getDenominator(), fps.getNumerator()));

    which yields the following output :

    Codec: CODEC_ID_H264
    Resolution: 1280x720
    Bitrate: 25000
    Bitrate Tolerance: 1000
    Framerate: 25.0

    H264 encoded video

    Now when I specify the MPEG4 codec, I get the following output :

    Codec: CODEC_ID_MPEG4
    Resolution: 1280x720
    Bitrate: 25000
    Bitrate Tolerance: 1000
    Framerate: 25.0

    MPEG4 encoded video

    As you can see, the only difference is the ICodec type (MPEG4 instead of H264) and the use of the preset (which is required by xuggler when using an H264 codec). Can anyone explain to me the huge difference in quality and tell me how to resolve the issue ?

  • avcodec/aom_film_grain : implement AFGS1 parsing

    26 février 2024, par Niklas Haas
    avcodec/aom_film_grain : implement AFGS1 parsing
    

    Based on the AOMedia Film Grain Synthesis 1 (AFGS1) spec :
    https://aomediacodec.github.io/afgs1-spec/

    The parsing has been changed substantially relative to the AV1 film
    grain OBU. In particular :

    1. There is the possibility of maintaining multiple independent film
    grain parameter sets, and decoders/players are recommended to pick
    the one most appropriate for the intended display resolution. This
    could also be used to e.g. switch between different grain profiles
    without having to re-signal the appropriate coefficients.

    2. Supporting this, it's possible to *predict* the grain coefficients
    from previously signalled parameter sets, transmitting only the
    residual.

    3. When not predicting, the parameter sets are now stored as a series of
    increments, rather than being directly transmitted.

    4. There are several new AFGS1-exclusive fields.

    I placed this parser in its own file, rather than h2645_sei.c, since
    nothing in the generic AFGS1 film grain payload is specific to T.35, and
    to compartmentalize the code base.

    • [DH] libavcodec/aom_film_grain.c
    • [DH] libavcodec/aom_film_grain.h
  • vvcdec : add CTU parser

    5 décembre 2023, par Nuo Mi
    vvcdec : add CTU parser
    

    Co-authored-by : Xu Mu <toxumu@outlook.com>
    Co-authored-by : Frank Plowman <post@frankplowman.com>
    Co-authored-by : Shaun Loo <shaunloo10@gmail.com>
    Co-authored-by : Wu Jianhua <toqsxw@outlook.com>

    • [DH] libavcodec/vvc/vvc_ctu.c
    • [DH] libavcodec/vvc/vvc_ctu.h