Recherche avancée

Médias (0)

Mot : - Tags -/metadatas

Aucun média correspondant à vos critères n’est disponible sur le site.

Autres articles (112)

  • Personnaliser en ajoutant son logo, sa bannière ou son image de fond

    5 septembre 2013, par

    Certains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;

  • 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

  • Librairies et binaires spécifiques au traitement vidéo et sonore

    31 janvier 2010, par

    Les logiciels et librairies suivantes sont utilisées par SPIPmotion d’une manière ou d’une autre.
    Binaires obligatoires FFMpeg : encodeur principal, permet de transcoder presque tous les types de fichiers vidéo et sonores dans les formats lisibles sur Internet. CF ce tutoriel pour son installation ; Oggz-tools : outils d’inspection de fichiers ogg ; Mediainfo : récupération d’informations depuis la plupart des formats vidéos et sonores ;
    Binaires complémentaires et facultatifs flvtool2 : (...)

Sur d’autres sites (17046)

  • Creating GIF from QImages with ffmpeg

    21 mars 2020, par Sierra

    I would like to generate GIF from QImage, using ffmpeg - all of that programmatically (C++). I’m working with Qt 5.6 and the last build of ffmpeg (build git-0a9e781 (2016-06-10).

    I’m already able to convert these QImage in .mp4 and it works. I tried to use the same principle for the GIF, changing format pixel and codec. GIF is generated with two pictures (1 second each), in 15 FPS.

    ## INITIALIZATION
    
#####################################################################
    

    
// Filepath : "C:/Users/.../qt_temp.Jv7868.gif"  
    
// Allocating an AVFormatContext for an output format...
    
avformat_alloc_output_context2(formatContext, NULL, NULL, filepath);
    

    
...
    

    
// Adding the video streams using the default format codecs and initializing the codecs.
    
stream = avformat_new_stream(formatContext, *codec);
    

    
AVCodecContext * codecContext = avcodec_alloc_context3(*codec);
    

    
context->codec_id       = codecId;
    
context->bit_rate       = 400000;
    
...
    
context->pix_fmt        = AV_PIX_FMT_BGR8;
    

    
...
    

    
// Opening the codec...
    
avcodec_open2(codecContext, codec, NULL);
    

    
...
    

    
frame = allocPicture(codecContext->width, codecContext->height, codecContext->pix_fmt);
    
tmpFrame = allocPicture(codecContext->width, codecContext->height, AV_PIX_FMT_RGBA);
    

    
...
    

    
avformat_write_header(formatContext, NULL);
    

    
## ADDING A NEW FRAME
    
#####################################################################
    

    
// Getting in parameter the QImage: newFrame(const QImage & image)
    
const qint32 width  = image.width();
    
const qint32 height = image.height();
    

    
// Converting QImage into AVFrame
    
for (qint32 y = 0; y < height; y++) {
    
    const uint8_t * scanline = image.scanLine(y);
    

    
    for (qint32 x = 0; x < width * 4; x++) {
    
        tmpFrame->data[0][y * tmpFrame->linesize[0] + x] = scanline[x];
    
    }
    
}
    

    
...
    

    
// Scaling...
    
if (codec->pix_fmt != AV_PIX_FMT_BGRA) {
    
    if (!swsCtx) {
    
        swsCtx = sws_getContext(codec->width, codec->height,
    
                                AV_PIX_FMT_BGRA,
    
                                codec->width, codec->height,
    
                                codec->pix_fmt,
    
                                SWS_BICUBIC, NULL, NULL, NULL);
    
    }
    

    
    sws_scale(swsCtx,
    
              (const uint8_t * const *)tmpFrame->data,
    
              tmpFrame->linesize,
    
              0,
    
              codec->height,
    
              frame->data,
    
              frame->linesize);
    
}
    
frame->pts = nextPts++;
    

    
...
    

    
int gotPacket = 0;
    
AVPacket packet = {0};
    

    
av_init_packet(&packet);
    
avcodec_encode_video2(codec, &packet, frame, &gotPacket);
    

    
if (gotPacket) {
    
    av_packet_rescale_ts(paket, *codec->time_base, stream->time_base);
    
    paket->stream_index = stream->index;
    

    
    av_interleaved_write_frame(formatContext, paket);
    
}

    But when I’m trying to modify the video codec and pixel format to match with GIF specifications, I’m facing some issues.
    I tried several codecs such as AV_CODEC_ID_GIF and AV_CODEC_ID_RAWVIDEO but none of them seem to work. During the initialization phase, avcodec_open2() always returns such kind of errors :

    Specified pixel format rgb24 is invalid or not supported
    
Could not open video codec:  gif

    EDIT 17/06/2016

    Digging a little bit more, avcodec_open2() returns -22 :

    #define EINVAL          22      /* Invalid argument */

    EDIT 22/06/2016

    Here are the flags used to compile ffmpeg :

    "FFmpeg/Libav configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmfx --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib"

    Did I miss a crucial one for GIF ?

    EDIT 27/06/2016

    Thanks to Gwen, I have a first output : I setted the context->pix_fmt to AV_PIX_FMT_BGR8. Btw I’m still facing some issues with the generated GIF. It’s not playing and encoding appears to fail.

    GIF generated in command lines with ffmpeg (left) . . . GIF generated programmatically (right)
    Generated in command line with ffmpeg
    enter image description here

    It looks like some options are not defined... also may be a wrong conversion between QImage and AVFrame ? I updated the code above. It represents a lot of code, so I tried to stay short. Don’t hesitate to ask more details.

    End of EDIT

    I’m not really familiar with ffmpeg, any kind of help would be highly appreciated. Thank you.

  • Creating GIF from QImages with ffmpeg

    17 août 2016, par Sierra

    I would like to generate GIF from QImage, using ffmpeg - all of that programmatically (C++). I’m working with Qt 5.6 and the last build of ffmpeg (build git-0a9e781 (2016-06-10).

    I’m already able to convert these QImage in .mp4 and it works. I tried to use the same principle for the GIF, changing format pixel and codec. GIF is generated with two pictures (1 second each), in 15 FPS.

    ## INITIALIZATION
    
#####################################################################
    

    
// Filepath : "C:/Users/.../qt_temp.Jv7868.gif"  
    
// Allocating an AVFormatContext for an output format...
    
avformat_alloc_output_context2(formatContext, NULL, NULL, filepath);
    

    
...
    

    
// Adding the video streams using the default format codecs and initializing the codecs.
    
stream = avformat_new_stream(formatContext, *codec);
    

    
AVCodecContext * codecContext = avcodec_alloc_context3(*codec);
    

    
context->codec_id       = codecId;
    
context->bit_rate       = 400000;
    
...
    
context->pix_fmt        = AV_PIX_FMT_BGR8;
    

    
...
    

    
// Opening the codec...
    
avcodec_open2(codecContext, codec, NULL);
    

    
...
    

    
frame = allocPicture(codecContext->width, codecContext->height, codecContext->pix_fmt);
    
tmpFrame = allocPicture(codecContext->width, codecContext->height, AV_PIX_FMT_RGBA);
    

    
...
    

    
avformat_write_header(formatContext, NULL);
    

    
## ADDING A NEW FRAME
    
#####################################################################
    

    
// Getting in parameter the QImage: newFrame(const QImage & image)
    
const qint32 width  = image.width();
    
const qint32 height = image.height();
    

    
// Converting QImage into AVFrame
    
for (qint32 y = 0; y < height; y++) {
    
    const uint8_t * scanline = image.scanLine(y);
    

    
    for (qint32 x = 0; x < width * 4; x++) {
    
        tmpFrame->data[0][y * tmpFrame->linesize[0] + x] = scanline[x];
    
    }
    
}
    

    
...
    

    
// Scaling...
    
if (codec->pix_fmt != AV_PIX_FMT_BGRA) {
    
    if (!swsCtx) {
    
        swsCtx = sws_getContext(codec->width, codec->height,
    
                                AV_PIX_FMT_BGRA,
    
                                codec->width, codec->height,
    
                                codec->pix_fmt,
    
                                SWS_BICUBIC, NULL, NULL, NULL);
    
    }
    

    
    sws_scale(swsCtx,
    
              (const uint8_t * const *)tmpFrame->data,
    
              tmpFrame->linesize,
    
              0,
    
              codec->height,
    
              frame->data,
    
              frame->linesize);
    
}
    
frame->pts = nextPts++;
    

    
...
    

    
int gotPacket = 0;
    
AVPacket packet = {0};
    

    
av_init_packet(&packet);
    
avcodec_encode_video2(codec, &packet, frame, &gotPacket);
    

    
if (gotPacket) {
    
    av_packet_rescale_ts(paket, *codec->time_base, stream->time_base);
    
    paket->stream_index = stream->index;
    

    
    av_interleaved_write_frame(formatContext, paket);
    
}

    But when I’m trying to modify the video codec and pixel format to match with GIF specifications, I’m facing some issues.
    I tried several codecs such as AV_CODEC_ID_GIF and AV_CODEC_ID_RAWVIDEO but none of them seem to work. During the initialization phase, avcodec_open2() always returns such kind of errors :

    Specified pixel format rgb24 is invalid or not supported
    
Could not open video codec:  gif

    EDIT 17/06/2016

    Digging a little bit more, avcodec_open2() returns -22 :

    #define EINVAL          22      /* Invalid argument */

    EDIT 22/06/2016

    Here are the flags used to compile ffmpeg :

    "FFmpeg/Libav configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmfx --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib"

    Did I miss a crucial one for GIF ?

    EDIT 27/06/2016

    Thanks to Gwen, I have a first output : I setted the context->pix_fmt to AV_PIX_FMT_BGR8. Btw I’m still facing some issues with the generated GIF. It’s not playing and encoding appears to fail.

    GIF generated in command lines with ffmpeg (left) . . . GIF generated programmatically (right)
    Generated in command line with ffmpeg
    enter image description here

    It looks like some options are not defined... also may be a wrong conversion between QImage and AVFrame ? I updated the code above. It represents a lot of code, so I tried to stay short. Don’t hesitate to ask more details.

    End of EDIT

    I’m not really familiar with ffmpeg, any kind of help would be highly appreciated. Thank you.

  • Revision 29944 : On peut comptabiliser les pages du privé

    17 juillet 2009, par kent1@… — Log

    On peut comptabiliser les pages du privé

Navigation