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  • Publier sur MédiaSpip

    13 juin 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

  • Les formats acceptés

    28 janvier 2010, par

    Les commandes suivantes permettent d’avoir des informations sur les formats et codecs gérés par l’installation local de ffmpeg :
    ffmpeg -codecs ffmpeg -formats
    Les format videos acceptés en entrée
    Cette liste est non exhaustive, elle met en exergue les principaux formats utilisés : h264 : H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 m4v : raw MPEG-4 video format flv : Flash Video (FLV) / Sorenson Spark / Sorenson H.263 Theora wmv :
    Les formats vidéos de sortie possibles
    Dans un premier temps on (...)

  • 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 (...)

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  • ffmpeg : can't concat pictures into a video if -pix_fmt is specified

    15 mars 2023, par roku

    I'm trying to concat multiple images into an .mp4 video with ffmpeg. I'm storing the images and their outpoints in a list file like this :

    


    file image1.png
outpoint 7.748208616780046
file image2.png
outpoint 26.714058956916098
file image3.png
outpoint 22.6253514739229


    


    Then I create a video from them with this command : ffmpeg -f concat -i images.txt merged.mp4.

    


    The problem is that the pictures have a transparent background and my command changes the transparency to the color black but I want to keep them transparent in the video too. I looked into it and it seems like the -pix_fmt flag should be used to achieve transparency but when I add the flag I get this output from my command (which is now ffmpeg -f concat -i images.txt -pix_fmt merged.mp4) :

    


    Trailing option(s) found in the command: may be ignored.
Input #0, concat, from 'images.txt':
  Duration: N/A, start: 0.000000, bitrate: N/A
  Stream #0:0: Video: png, rgba(pc, gbr/unknown/unknown), 900x184, 25 fps, 25 tbr, 25 tbn
At least one output file must be specified


    


    I don't understand why it's not working since the structure of the list file stayed the same so it should be able to find the images the same way. Any ideas ?

    


  • vc1dec : fieldtx is only valid for interlaced frame pictures

    31 janvier 2013, par Sebastian Sandberg
    vc1dec : fieldtx is only valid for interlaced frame pictures
    

    The fieldtx_plane is not cleared for interlaced fields.

    Signed-off-by : Martin Storsjö <martin@martin.st>

    • [DBH] libavcodec/vc1dec.c
  • hevc : Validate the number of long term reference pictures

    23 juin 2017, par Mark Thompson
    hevc : Validate the number of long term reference pictures
    

    This would overflow if the stream contained a value greater than the
    maximum allowed by the standard (32).

    • [DBH] libavcodec/hevc_ps.c