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  • Le plugin : Podcasts.

    14 juillet 2010, par

    Le problème du podcasting est à nouveau un problème révélateur de la normalisation des transports de données sur Internet.
    Deux formats intéressants existent : Celui développé par Apple, très axé sur l’utilisation d’iTunes dont la SPEC est ici ; Le format "Media RSS Module" qui est plus "libre" notamment soutenu par Yahoo et le logiciel Miro ;
    Types de fichiers supportés dans les flux
    Le format d’Apple n’autorise que les formats suivants dans ses flux : .mp3 audio/mpeg .m4a audio/x-m4a .mp4 (...)

  • 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 (...)

  • XMP PHP

    13 mai 2011, par

    Dixit Wikipedia, XMP signifie :
    Extensible Metadata Platform ou XMP est un format de métadonnées basé sur XML utilisé dans les applications PDF, de photographie et de graphisme. Il a été lancé par Adobe Systems en avril 2001 en étant intégré à la version 5.0 d’Adobe Acrobat.
    Étant basé sur XML, il gère un ensemble de tags dynamiques pour l’utilisation dans le cadre du Web sémantique.
    XMP permet d’enregistrer sous forme d’un document XML des informations relatives à un fichier : titre, auteur, historique (...)

Sur d’autres sites (8345)

  • Xamarin Mac FFmpeg launch path not accessible

    25 mars 2024, par Tecnopresley

    I have a Xamarin Forms project with Mac support and I am trying to implement FFmpeg, so I have downloaded the Static build from its official page and added it as in the resources folder of the Mac project with the build action in Content, then I have created a service that will basically remove the audio from a video that I indicate in a path with a FFmpeg command, to do the service I have based on the following answer and I have adapted it to C # :
https://stackoverflow.com/a/37422688/8496520

    


    The problem is that when I try to execute the command I get the following error :

    


    "NSInvalidArgumentException: launch path not accessible"


    


    And I can't find out why this happens, I use the following code in the service (The error occurs when calling the Launch () method of the NSTask) :

    


    public void ExecuteFFmpeg()
{
    try
    {
        var launchPath = NSBundle.MainBundle.PathForResource("ffmpeg", ofType: "");
        var compressTask = new NSTask();
        compressTask.LaunchPath = launchPath;
        compressTask.Arguments = new string[] {
            "-i",
            "downloads/test.mp4",
            "-c",
            "copy",
            "-an",
            "nosound.mp4" };
        compressTask.StandardInput = NSFileHandle.FromNullDevice();
        compressTask.Launch();
        compressTask.WaitUntilExit();
    }
    catch (Exception ex)
    {

    }


    


  • ffmpeg xfade custom transition expression - Fetch pixel value at specifc x, y from vid1, vid2 ?

    25 janvier 2021, par jsaluja

    I am using xfade with transition=custom, and trying to build expression.
I am referring to official documentation https://ffmpeg.org/ffprobe-all.html#xfade

    


    Per my understanding, expression should return pixel value of merged video

    


    I built a few custom transitions using expressions that return some combination of A, B

    


    For eg.,

    


    "custom:expr='if(gt(P, abs(X/W - 0.5)), A, B)'"
"custom:expr='lerp(A, B, 1 - P)'"


    


    For the next set of transitions, I want to fetch the pixel values from source, target video at specific positions, and combine them in my expressions

    


    I tried using a0(X, Y), b0(X, Y) etc inside of

    


    xfade=transition=custom:expr='r....


    


    I ran into exceptions with ffmpeg complaining it doesn't understand the expression.

    


    Can someone clarify, how i can fetch pixel values as specific position from source, target video and combine them in expression ?

    


  • How to fetch pixel value at specifc x, y from vid1, vid2 in ffmpeg xfade custom transition expression

    25 janvier 2021, par jsaluja

    I am using xfade with transition=custom, and trying to build expression.
I am referring to official documentation https://ffmpeg.org/ffprobe-all.html#xfade

    


    Per my understanding, expression should return pixel value of merged video

    


    I built a few custom transitions using expressions that return some combination of A, B

    


    For eg.,

    


    "custom:expr='if(gt(P, abs(X/W - 0.5)), A, B)'"
"custom:expr='lerp(A, B, 1 - P)'"


    


    For the next set of transitions, I want to fetch the pixel values from source, target video at specific positions, and combine them in my expressions

    


    I tried using a0(X, Y), b0(X, Y) etc inside of

    


    xfade=transition=custom:expr='r....


    


    I ran into exceptions with ffmpeg complaining it doesn't understand the expression.

    


    Can someone clarify, how i can fetch pixel values as specific position from source, target video and combine them in expression ?

    


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