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  • Les autorisations surchargées par les plugins

    27 avril 2010, par

    Mediaspip core
    autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs

  • Problèmes fréquents

    10 mars 2010, par

    PHP et safe_mode activé
    Une des principales sources de problèmes relève de la configuration de PHP et notamment de l’activation du safe_mode
    La solution consiterait à soit désactiver le safe_mode soit placer le script dans un répertoire accessible par apache pour le site

  • Qu’est ce qu’un éditorial

    21 juin 2013, par

    Ecrivez votre de point de vue dans un article. Celui-ci sera rangé dans une rubrique prévue à cet effet.
    Un éditorial est un article de type texte uniquement. Il a pour objectif de ranger les points de vue dans une rubrique dédiée. Un seul éditorial est placé à la une en page d’accueil. Pour consulter les précédents, consultez la rubrique dédiée.
    Vous pouvez personnaliser le formulaire de création d’un éditorial.
    Formulaire de création d’un éditorial Dans le cas d’un document de type éditorial, les (...)

Sur d’autres sites (11253)

  • Find video resolution and video duration of remote mediafile

    22 février 2012, par osgx

    I want to write an program which can find some metainformation of mediafile. I'm interested in popular video formats, such as avi, mkv, mp4, mov (may be other popular too). I want basically to get :

    • Video size (720, 1080, 360 etc)
    • Total runtime of video (may be not very exact)
    • Number of audio streams
    • Name of video codec
    • Name of audio codec

    There is already the mediainfo, but in my program I want to get information about remote file, which may be accessed via ftp, http, samba ; or even torrent (there are some torrent solutions, which allows to read not-yet downloaded file).

    MediaInfo library have no support of samba (smb ://) and mkv format (for runtime).

    Also, I want to know, how much data should be downloaded to get this information. I want not to download full videofile because I have no enough disk space.

    Is this information in the first 1 or 10 or 100 KiloBytes of the file ? Is it at predictable offset if I know the container name and total file size ?

    PS : Platform is Linux, Language is C/C++

  • Copying avcodec parameters

    4 juin 2020, par Ayxan

    I am trying to use libav to convert an MP4 file to an MP3 file. Basically trying to achieve what ffmpeg -i filename.mp4 filename.mp3 does. I've found this official example. But when I run it with an input MP4 and an output MP3 I get an error :

    



    


    Invalid audio stream. Exactly one MP3 audio stream is required.

    


    



    I am not at all familiar with this library but I think I have narrowed the problem down to this line :

    



    ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);


    



    It seems to copy all streams for a video file but we only need one for the MP3 file ? I am not sure. There doesn't seem to be a function to copy only the parameters relevant to audio. I checked the sources, avcodec_parameters_copy does a simple memcpy.

    



    Questions :

    



      

    1. Is this the actual problem ?

      2. 


    2. How do I solve it ?

      3. 


    3. Am I on the right track to achieve the goal of extracting audio from a video file ? I've seen this question (and other similar questions like this and this) on here but none seem to have a complete code example. The C API documentation for this library is also a little lacking.

      4. 


    


  • OpenCV ffmpeg issues when running Windows 10 app on Windows 7

    1er novembre 2016, par David G.

    I need to maintain a desktop app written in C++, using Qt and OpenCV for some video processing. As far as I understood, the decoding part of OpenCV is delegated to ffmpeg in a separate DLL for licensing reasons.

    The development environment is on Windows 10, using QT Creator and MSVC12 64-bit as compiler. OpenCV version is 3.0, the official distribution. Here, everything runs fine, I am able to decode a video using VideoCapture::open().

    Issues arise when I try to run the application in a standalone fashion with all the required DLLs in the same folder as the .exe file. All cases below are 64-bit OSes.

    On a Windows 10 computer, not the same as the developement machine and no developer libraries present, the video decoding works fine. I have tested on a Windows 8 machine as well, no issues so far.

    On Windows 7, the things get tricky. The same video files that successfully load during the previous tests are not recognized by the app at all i.e. the isOpened call on VideoCapture returns false. For further testing, I stripped the opencv_ffmpeg300_64.dll file to narrow down the issue on Windows 10 and 8 ; as expected, without this DLL the app is no more able to open the same video files.

    It seems that the DLL is simply not recognized on Windows 7.

    • Did you encounter this type of issue and, maybe, have part of a solution ?
    • I would like to monitor which DLLs are loaded as the program runs and see possible "DLL not found" errors. Is it possible, especially on a machine that does not have the entire developement environment ?
    • Can building OpenCV on my own address the issue ?
    • Even further, would it be worth to port the development environment on Windows 7 and build from there ? This requires significant work due to the project itself.

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