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  • MediaSPIP Player : problèmes potentiels

    22 février 2011, par

    Le lecteur ne fonctionne pas sur Internet Explorer
    Sur Internet Explorer (8 et 7 au moins), le plugin utilise le lecteur Flash flowplayer pour lire vidéos et son. Si le lecteur ne semble pas fonctionner, cela peut venir de la configuration du mod_deflate d’Apache.
    Si dans la configuration de ce module Apache vous avez une ligne qui ressemble à la suivante, essayez de la supprimer ou de la commenter pour voir si le lecteur fonctionne correctement : /** * GeSHi (C) 2004 - 2007 Nigel McNie, (...)

  • 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 (...)

  • Contribute to a better visual interface

    13 avril 2011

    MediaSPIP is based on a system of themes and templates. Templates define the placement of information on the page, and can be adapted to a wide range of uses. Themes define the overall graphic appearance of the site.
    Anyone can submit a new graphic theme or template and make it available to the MediaSPIP community.

Sur d’autres sites (3490)

  • Understanding the VP8 Token Tree

    7 juin 2010, par Multimedia Mike — VP8

    I got tripped up on another part of the VP8 decoding process today. So I drew a picture to help myself understand it. Then I went back and read David Conrad’s comment on my last post regarding my difficulty understanding the VP8 spec and saw that he ran into the same problem. Since we both experienced the same hindrance in trying to sort out this matter, I thought I may as well publish the picture I drew.

    VP8 defines various trees for decoding different syntax elements. There is one tree for decoding the tokens and it is expressed in the VP8 spec as such :

    PLAIN TEXT
    C :
    1. const tree_index coef_tree [2 * (num_dct_tokens - 1)] =
    2. {
    3.  -dct_eob, 2,        /* eob = "0"  */
    4.   -DCT_0, 4,        /* 0  = "10" */
    5.   -DCT_1, 6,        /* 1  = "110" */
    6.    8, 12,
    7.    -DCT_2, 10,      /* 2  = "11100" */
    8.     -DCT_3, -DCT_4,    /* 3  = "111010", 4 = "111011" */
    9.    14, 16,
    10.     -dct_cat1, -dct_cat2, /* cat1 = "111100", cat2 = "111101" */
    11.    18, 20,
    12.     -dct_cat3, -dct_cat4, /* cat3 = "1111100", cat4 = "1111101" */
    13.     -dct_cat5, -dct_cat6 /* cat4 = "1111110", cat4 = "1111111" */
    14. } ;

    Here is what the table looks like when you make a tree out of it (click for full size image) :



    The catch is that it makes no sense for an end-of-block (EOB) token to follow a 0 token since EOB already indicates that the remainder of the coefficients should be 0 anyway. Thus, the spec states that, "decoding of certain DCT coefficients may skip the first branch, whose preceding coefficient is a DCT_0." I confess, I didn’t understand what "skip the first branch" meant until I drew the tree.



    For those wondering why it might be sub-optimal (clarity-wise) for a spec to simply regurgitate vast chunks of C code, this makes a decent case. As you can see, the spec makes certain assumptions about how a binary tree should be organized in a static array (node n points to elements n*2 and n*2+1 as its branches ; leaves are either negative or 0). This is the second method I have seen ; another piece of code (not the VP8 spec) had the nodes in the first half of the array and pointed to leaves in the second half. There must be other arrangements.

  • Opera 10.60 Released with WebM Support

    7 juillet 2010, par noreply@blogger.com (John Luther)

    Congratulations to everyone at Opera Software for releasing version 10.60 of their browser, which supports WebM video playback. Downloads for Windows, Mac OS and Linux are available on the Opera download page.

  • A nice comparison of mics

    3 juin 2010

    DVEStore has done a great comparison of different types of microphones on video. Audio is a black art, and folks rarely put in the time to do A/B/C comparisons. We tend to just default to a set of mics that we’ve decided are "good enough" and then don’t go back to reevaluate.

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