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  • Le profil des utilisateurs

    12 avril 2011, par

    Chaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
    L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...)

  • Configurer la prise en compte des langues

    15 novembre 2010, par

    Accéder à la configuration et ajouter des langues prises en compte
    Afin de configurer la prise en compte de nouvelles langues, il est nécessaire de se rendre dans la partie "Administrer" du site.
    De là, dans le menu de navigation, vous pouvez accéder à une partie "Gestion des langues" permettant d’activer la prise en compte de nouvelles langues.
    Chaque nouvelle langue ajoutée reste désactivable tant qu’aucun objet n’est créé dans cette langue. Dans ce cas, elle devient grisée dans la configuration et (...)

  • Submit enhancements and plugins

    13 avril 2011

    If you have developed a new extension to add one or more useful features to MediaSPIP, let us know and its integration into the core MedisSPIP functionality will be considered.
    You can use the development discussion list to request for help with creating a plugin. As MediaSPIP is based on SPIP - or you can use the SPIP discussion list SPIP-Zone.

Sur d’autres sites (7158)

  • image -> video -> image not lossless using avconv

    15 décembre 2015, par nrob

    I’m trying to test the amount of information lost with some different video codecs. I’ve got a python script which uses PyPNG to write a series of 8 bit RGB images. I then encode it using avconv, for instance

    avconv -r 1 -i ../frames/data%03d.png -c:v ffv1 -qscale:v 0 -r 1

    outffv1.avi

    I then decode this back into pngs like so

    avconv -r 1 -i outffv1.avi -r 1 ./outffv1/frame%03d.png

    But when I compare the images before and after the video compression, they are different (mean absolute error of 15%). The thing that is confusing me is that this is true (give or take) independent of the codec.

    For instance, I get similar answers for libtheora for a range of qscale values.

    The png encoding i.e. write to png, and immediately load back in without and video compression step, is lossless.

  • ffmpeg reverts audio volume even after removing the audio track

    7 avril 2023, par DniweTamp

    I tried making a simple batch file that separates and normalizes audio track, and merges it with the reencoded video track afterwards, but whenever I try to add the edited audio track back the volume just goes back to the original level.

    


    It happens specifically when I try to add the audio back to video, the volume level stays normalized if I reencode said audio to .aac or .ogg files, but when I try to add it to the video, even using -c:a copy, the volume just reverts to the original level

    


    Below is an image that shows the volume levels of audio tracks

    


    I detach audio, normalize it (result is top track), add it back to the video, and it becomes what's on the bottom (which is also the same volume as the original video's audio)
Normalized and quiet volume levels

    


    Here's the contents of my batch file, expected result was a reencoded video, with normalized audio

    


    I tried removing audio track with both -an and -map 0 -map -0:a, same result

    


    I can confirm that the normalize program does its job correctly, by checking volume levels in audacity

    


    ffmpeg -i %1 -y temp.wav
normalize.exe temp.wav
ffmpeg -i %1 -c:v libx264 -map 0 -map -0:a -profile:v main -pix_fmt yuv420p -movflags +faststart -preset medium -crf 22 -map_metadata -1 -y video.temp.mp4
ffmpeg -i %1 -i temp.wav -c:v copy -y video.h264.mp4
del temp.wav
del video.temp.mp4


    


    Edit : and here's the video file I tried this on.

    


  • avcodec/mpeg4videodec : Remove use of FF_PROFILE_MPEG4_SIMPLE_STUDIO as indicator...

    3 juillet 2018, par Michael Niedermayer
    avcodec/mpeg4videodec : Remove use of FF_PROFILE_MPEG4_SIMPLE_STUDIO as indicator of studio profile

    The profile field is changed by code inside and outside the decoder,
    
its not a reliable indicator of the internal codec state.
    
Maintaining it consistency with studio_profile is messy.
    
Its easier to just avoid it and use only studio_profile
    

    Fixes : assertion failure
    
Fixes : ffmpeg_crash_9.avi
    

    Found-by : Thuan Pham, Marcel Böhme, Andrew Santosa and Alexandru Razvan Caciulescu with AFLSmart
    
Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
    • [DH] libavcodec/error_resilience.c
    • [DH] libavcodec/h263dec.c
    • [DH] libavcodec/mpeg4videodec.c

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