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Autres articles (90)

  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

  • Menus personnalisés

    14 novembre 2010, par

    MediaSPIP utilise le plugin Menus pour gérer plusieurs menus configurables pour la navigation.
    Cela permet de laisser aux administrateurs de canaux la possibilité de configurer finement ces menus.
    Menus créés à l’initialisation du site
    Par défaut trois menus sont créés automatiquement à l’initialisation du site : Le menu principal ; Identifiant : barrenav ; Ce menu s’insère en général en haut de la page après le bloc d’entête, son identifiant le rend compatible avec les squelettes basés sur Zpip ; (...)

  • 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

Sur d’autres sites (11596)

  • FFmpeg API : parse raw movie packet data into AVPacket

    7 novembre 2011, par Andrea3000

    If you have a movie file and you need to extract frame (packet) from it, it's simply a matter of writing :

    avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
    

    
...
    

    
AVPacket packet;
    
av_read_frame(formatContext, &packet);

    But what if I don't have the movie file but only unparsed, raw packet data ? These raw packet data are the same as the raw data contained into the movie file but I don't access them throught avformat_open_input and therefore I can't use av_read_frame so FFmpeg doesn't parse them.

    How can I parse this raw data in order to build the corresponding AVPacket ?
    I need to obtain an AVPacket identical to the ones provided by av_read_frame.

  • How do I pre-allocate the memory for libavcodec to write decoded frame data ?

    18 décembre 2018, par codemonkey

    I am trying to decode a video with libav by following the demo code : here

    I need to be able to control where the frame data in pFrame->data[0] is stored. I have tried setting pFrame->data to my own buffer as follows :

    // Determine required buffer size and allocate buffer 
    
int numBytes = av_image_get_buffer_size(pixFmt, width, height, 1); 
    
(uint8_t*) dataBuff = (uint8_t*) malloc (numBytes * sizeof(uint8_t)); 
    

    
// Assign buffer to image planes in pFrame
    
av_image_fill_arrays(frame->data, frame->linesize, dataBuff, pixFmt, width,
    
height, 1);

    While this does set pFrame->data to be dataBuff (if I print their addresses, they are the same), this call ret = avcodec_receive_frame(pCodecContext, pFrame) to receive the decoded data always writes the data to a different address. It seems to manage its own memory somewhere in the underlying API and ignores the dataBuff that I assigned to pFrame right before.

    So I’m stuck—how can I tell libav to write decoded frame data to memory that I pre-allocate ? I’ve seen people ask similar questions online and in the libav forum but haven’t been able to find an answer.

    Many thanks 

  • vc2enc : prevent random data

    5 mai 2016, par Christophe Gisquet
    vc2enc : prevent random data

    The slice prefix is 0 in the reference encoder and the decoder ignores it.
    
Writing 0 there seems like the best temporary solution.
    

    The padding could have contained uninitialized data, but reference VC2
    
encoders put 0xFF there, hence the memset value.
    

    Overall this allows producing bistreams with no random data for use by fate.
    • [DH] libavcodec/vc2enc.c

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