Recherche avancée

Médias (0)

Mot : - Tags -/diogene

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

Autres articles (60)

  • Gestion des droits de création et d’édition des objets

    8 février 2011, par

    Par défaut, beaucoup de fonctionnalités sont limitées aux administrateurs mais restent configurables indépendamment pour modifier leur statut minimal d’utilisation notamment : la rédaction de contenus sur le site modifiables dans la gestion des templates de formulaires ; l’ajout de notes aux articles ; l’ajout de légendes et d’annotations sur les images ;

  • Dépôt de média et thèmes par FTP

    31 mai 2013, par

    L’outil MédiaSPIP traite aussi les média transférés par la voie FTP. Si vous préférez déposer par cette voie, récupérez les identifiants d’accès vers votre site MédiaSPIP et utilisez votre client FTP favori.
    Vous trouverez dès le départ les dossiers suivants dans votre espace FTP : config/ : dossier de configuration du site IMG/ : dossier des média déjà traités et en ligne sur le site local/ : répertoire cache du site web themes/ : les thèmes ou les feuilles de style personnalisées tmp/ : dossier de travail (...)

  • Keeping control of your media in your hands

    13 avril 2011, par

    The vocabulary used on this site and around MediaSPIP in general, aims to avoid reference to Web 2.0 and the companies that profit from media-sharing.
    While using MediaSPIP, you are invited to avoid using words like "Brand", "Cloud" and "Market".
    MediaSPIP is designed to facilitate the sharing of creative media online, while allowing authors to retain complete control of their work.
    MediaSPIP aims to be accessible to as many people as possible and development is based on expanding the (...)

Sur d’autres sites (8703)

  • Encoding video only FLV

    25 mars 2012, par NadavRub

    I am trying to generate a video only FLV file, I am using :

    1. libx264 + ffmpeg
    2. 30 fps ( fixed )
    3. playback is done using VLC 2.0.1 and flowplayer

    When playing the FLV the frame-rate seems 1 frame per sec, following is the way I cfg ffmpeg :

    AVOutputFormat* fmtOutput = av_oformat_next(0);
    while((0 != fmtOutput) && (0 != strcmp(fmtOutput->name, "flv")))
       fmtOutput = av_oformat_next(fmtOutput);
    m_pFmtCtxOutput          = avformat_alloc_context();
    m_pFmtCtxOutput->oformat = fmtOutput;

    AVStream* pOutVideoStream= av_new_stream(m_pFmtCtxOutput, pInVideoStream->id);
    AVCodec*  videoEncoder   = avcodec_find_encoder(CODEC_ID_H264);

    pOutVideoStream->codec->width    = 640;
    pOutVideoStream->codec->height   = 480;
    pOutVideoStream->codec->level    = 30;
    pOutVideoStream->codec->pix_fmt  = PIX_FMT_YUV420P;
    pOutVideoStream->codec->bit_rate = 3000000;

    pOutVideoStream->cur_dts         = 0;
    pOutVideoStream->first_dts       = 0;
    pOutVideoStream->index           = 0;
    pOutVideoStream->avg_frame_rate  = (AVRational){ 30, 1 };
    pOutVideoStream->time_base       =
    pOutVideoStream->codec->time_base= (AVRational){ 1, 30000 };
    pOutVideoStream->codec->gop_size = 30;
    %% Some specific libx264 settings %%
    m_dVideoStep                     = 1000;// packet dts/pts is incremented by this amount each frame

    pOutVideoStream->codec->flags   |= CODEC_FLAG_GLOBAL_HEADER;
    avcodec_open(pOutVideoStream->codec, videoEncoder);

    The resulting file seems OK, with the exception of the playback frame-rate.
    having in mind that :

    1. pOutVideoStream->avg_frame_rate = (AVRational) 30, 1  ;
    2. pOutVideoStream->time_base = (AVRational) 1, 30000  ;
    3. pOutVideoStream->codec->time_base= (AVRational) 1, 30000  ;
    4. For each frame I increment the dts/pts by 1000

    What am I doing wrong here ? why the file is playing choppy ( 1 fps ) ?

    Any help will be appreciated.

    Nadav at Sophin

  • Revision ccef8842d2 : Allow full coeff probability model and cost update This commit moves the simpli

    13 août 2014, par Jingning Han

    Changed Paths :
     Modify /vp9/encoder/vp9_speed_features.c



    Allow full coeff probability model and cost update

    This commit moves the simplified coefficient probability model
    and costing update to speed 4, and turns on chessboard pattern
    mode search for sub 720p sequences. The overall coding performance
    of speed 3 is improved :
    derf 0.889%
    stdhd 1.744%

    The speed 3 runtime for test sequences are improved :
    bus cif at 1000 kbps 9823 ms -> 9642 ms
    pedestrian 1080p 2000 kbps 189559 ms -> 183284 ms

    Change-Id : Iecbc7496a68f31fd49fb09f8dfd97c028d675a5d

  • Cropping Square Video using FFmpeg

    27 juin 2014, par zoruc

    Updated

    So I am trying to decode a mp4 file, crop the video into a square, and then re encode it back out to another mp4 file. This is my current code but there are a few issues with it.

    One is that the video doesn’t keep its rotation after the video has been re encoded

    Second is that the frames get outputted in a very fast video file that is not the same length as the original

    Third is that there is no sound

    Lastly and most importantly is do I need AVFilter to do the frame cropping or can it just be done per frame as a resize of the frame and then encoded back out.

    const char *inputPath = "test.mp4";
    const char *outPath = "cropped.mp4";
    const char *outFileType = "mp4";

    static AVFrame *oframe = NULL;
    static AVFilterGraph *filterGraph = NULL;  
    static AVFilterContext *crop_ctx = NULL;
    static AVFilterContext *buffersink_ctx = NULL;
    static AVFilterContext *buffer_ctx = NULL;

    int err;

    int crop_video(int width, int height) {

    av_register_all();
    avcodec_register_all();
    avfilter_register_all();

    AVFormatContext *inCtx = NULL;

    // open input file
    err = avformat_open_input(&inCtx, inputPath, NULL, NULL);
    if (err < 0) {
       printf("error at open input in\n");
       return err;
    }

    // get input file stream info
    err = avformat_find_stream_info(inCtx, NULL);
    if (err < 0) {
       printf("error at find stream info\n");
       return err;
    }

    // get info about video
    av_dump_format(inCtx, 0, inputPath, 0);

    // find video input stream
    int vs = -1;
    int s;
    for (s = 0; s < inCtx->nb_streams; ++s) {
       if (inCtx->streams[s] && inCtx->streams[s]->codec && inCtx->streams[s]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
           vs = s;
           break;
       }
    }

    // check if video stream is valid
    if (vs == -1) {
       printf("error at open video stream\n");
       return -1;
    }

    // set output format
    AVOutputFormat * outFmt = av_guess_format(outFileType, NULL, NULL);
    if (!outFmt) {
       printf("error at output format\n");
       return -1;
    }

    // get an output context to write to
    AVFormatContext *outCtx = NULL;
    err = avformat_alloc_output_context2(&outCtx, outFmt, NULL, NULL);
    if (err < 0 || !outCtx) {
       printf("error at output context\n");
       return err;
    }

    // input and output stream
    AVStream *outStrm = avformat_new_stream(outCtx, NULL);
    AVStream *inStrm = inCtx->streams[vs];

    // add a new codec for the output stream
    AVCodec *codec = NULL;
    avcodec_get_context_defaults3(outStrm->codec, codec);

    outStrm->codec->thread_count = 1;

    outStrm->codec->coder_type = AVMEDIA_TYPE_VIDEO;

    if(outCtx->oformat->flags & AVFMT_GLOBALHEADER) {
       outStrm->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
    }

    outStrm->codec->sample_aspect_ratio = outStrm->sample_aspect_ratio = inStrm->sample_aspect_ratio;

    err = avio_open(&outCtx->pb, outPath, AVIO_FLAG_WRITE);
    if (err < 0) {
       printf("error at opening outpath\n");
       return err;
    }

    outStrm->disposition = inStrm->disposition;
    outStrm->codec->bits_per_raw_sample = inStrm->codec->bits_per_raw_sample;
    outStrm->codec->chroma_sample_location = inStrm->codec->chroma_sample_location;
    outStrm->codec->codec_id = inStrm->codec->codec_id;
    outStrm->codec->codec_type = inStrm->codec->codec_type;

    if (!outStrm->codec->codec_tag) {
       if (! outCtx->oformat->codec_tag
           || av_codec_get_id (outCtx->oformat->codec_tag, inStrm->codec->codec_tag) == outStrm->codec->codec_id
           || av_codec_get_tag(outCtx->oformat->codec_tag, inStrm->codec->codec_id) <= 0) {
           outStrm->codec->codec_tag = inStrm->codec->codec_tag;
       }
    }

    outStrm->codec->bit_rate = inStrm->codec->bit_rate;
    outStrm->codec->rc_max_rate = inStrm->codec->rc_max_rate;
    outStrm->codec->rc_buffer_size = inStrm->codec->rc_buffer_size;

    const size_t extra_size_alloc = (inStrm->codec->extradata_size > 0) ?
    (inStrm->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE) :
    0;

    if (extra_size_alloc) {
       outStrm->codec->extradata = (uint8_t*)av_mallocz(extra_size_alloc);
       memcpy( outStrm->codec->extradata, inStrm->codec->extradata, inStrm->codec->extradata_size);
    }

    outStrm->codec->extradata_size = inStrm->codec->extradata_size;

    AVRational input_time_base = inStrm->time_base;
    AVRational frameRate = {25, 1};
    if (inStrm->r_frame_rate.num && inStrm->r_frame_rate.den
       && (1.0 * inStrm->r_frame_rate.num / inStrm->r_frame_rate.den < 1000.0)) {
       frameRate.num = inStrm->r_frame_rate.num;
       frameRate.den = inStrm->r_frame_rate.den;
    }

    outStrm->r_frame_rate = frameRate;
    outStrm->codec->time_base = inStrm->codec->time_base;

    outStrm->codec->pix_fmt = inStrm->codec->pix_fmt;
    outStrm->codec->width = width;
    outStrm->codec->height =  height;
    outStrm->codec->has_b_frames =  inStrm->codec->has_b_frames;

    if (!outStrm->codec->sample_aspect_ratio.num) {
       AVRational r0 = {0, 1};
       outStrm->codec->sample_aspect_ratio =
       outStrm->sample_aspect_ratio =
       inStrm->sample_aspect_ratio.num ? inStrm->sample_aspect_ratio :
       inStrm->codec->sample_aspect_ratio.num ?
       inStrm->codec->sample_aspect_ratio : r0;
    }

    avformat_write_header(outCtx, NULL);

    filterGraph = avfilter_graph_alloc();
    if (!filterGraph) {
       printf("could not open filter graph");
       return -1;
    }

    AVFilter *crop = avfilter_get_by_name("crop");
    AVFilter *buffer = avfilter_get_by_name("buffer");
    AVFilter *buffersink = avfilter_get_by_name("buffersink");

    char args[512];

    snprintf(args, sizeof(args), "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
            width, height, inStrm->codec->pix_fmt,
            inStrm->codec->time_base.num, inStrm->codec->time_base.den,
            inStrm->codec->sample_aspect_ratio.num, inStrm->codec->sample_aspect_ratio.den);

    err = avfilter_graph_create_filter(&buffer_ctx, buffer, NULL, args, NULL, filterGraph);
    if (err < 0) {
       printf("error initializing buffer filter\n");
       return err;
    }

    err = avfilter_graph_create_filter(&buffersink_ctx, buffersink, NULL, NULL, NULL, filterGraph);
    if (err < 0) {
       printf("unable to create buffersink filter\n");
       return err;
    }
    snprintf(args, sizeof(args), "%d:%d", width, height);
    err = avfilter_graph_create_filter(&crop_ctx, crop, NULL, args, NULL, filterGraph);
    if (err < 0) {
       printf("error initializing crop filter\n");
       return err;
    }

    err = avfilter_link(buffer_ctx, 0, crop_ctx, 0);
    if (err < 0) {
       printf("error linking filters\n");
       return err;
    }

    err = avfilter_link(crop_ctx, 0, buffersink_ctx, 0);
    if (err < 0) {
       printf("error linking filters\n");
       return err;
    }

    err = avfilter_graph_config(filterGraph, NULL);
    if (err < 0) {
       printf("error configuring the filter graph\n");
       return err;
    }

    printf("filtergraph configured\n");

    for (;;) {

       AVPacket packet = {0};
       av_init_packet(&packet);

       err = AVERROR(EAGAIN);
       while (AVERROR(EAGAIN) == err)
           err = av_read_frame(inCtx, &packet);

       if (err < 0) {
           if (AVERROR_EOF != err && AVERROR(EIO) != err) {
               printf("eof error\n");
               return 1;
           } else {
               break;
           }
       }

       if (packet.stream_index == vs) {

           //
           //            AVPacket pkt_temp_;
           //            memset(&pkt_temp_, 0, sizeof(pkt_temp_));
           //            AVPacket *pkt_temp = &pkt_temp_;
           //
           //            *pkt_temp = packet;
           //
           //            int error, got_frame;
           //            int new_packet = 1;
           //
           //            error = avcodec_decode_video2(inStrm->codec, frame, &got_frame, pkt_temp);
           //            if(error < 0) {
           //                LOGE("error %d", error);
           //            }
           //
           //            // if (error >= 0) {
           //
           //            // push the video data from decoded frame into the filtergraph
           //            int err = av_buffersrc_write_frame(buffer_ctx, frame);
           //            if (err < 0) {
           //                LOGE("error writing frame to buffersrc");
           //                return -1;
           //            }
           //            // pull filtered video from the filtergraph
           //            for (;;) {
           //                int err = av_buffersink_get_frame(buffersink_ctx, oframe);
           //                if (err == AVERROR_EOF || err == AVERROR(EAGAIN))
           //                    break;
           //                if (err < 0) {
           //                    LOGE("error reading buffer from buffersink");
           //                    return -1;
           //                }
           //            }
           //
           //            LOGI("output frame");

           err = av_interleaved_write_frame(outCtx, &packet);
           if (err < 0) {
               printf("error at write frame");
               return -1;
           }

           //}
       }

       av_free_packet(&packet);
    }

    av_write_trailer(outCtx);
    if (!(outCtx->oformat->flags & AVFMT_NOFILE) && outCtx->pb)
       avio_close(outCtx->pb);

    avformat_free_context(outCtx);
    avformat_close_input(&inCtx);

    return 0;

    }