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Le profil des utilisateurs
12 avril 2011, parChaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...) -
Configurer la prise en compte des langues
15 novembre 2010, parAccéder à la configuration et ajouter des langues prises en compte
Afin de configurer la prise en compte de nouvelles langues, il est nécessaire de se rendre dans la partie "Administrer" du site.
De là, dans le menu de navigation, vous pouvez accéder à une partie "Gestion des langues" permettant d’activer la prise en compte de nouvelles langues.
Chaque nouvelle langue ajoutée reste désactivable tant qu’aucun objet n’est créé dans cette langue. Dans ce cas, elle devient grisée dans la configuration et (...) -
HTML5 audio and video support
13 avril 2011, parMediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
For older browsers the Flowplayer flash fallback is used.
MediaSPIP allows for media playback on major mobile platforms with the above (...)
Sur d’autres sites (4849)
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How do I set the framerate/FPS in an FFmpeg code (C) ?
2 juin 2020, par Tobias v. BrevernI try to encode single pictures to a .avi video. The goal is to have every picture displayed for a set amount of seconds to create a slide show. I tried my script with 10 pictures and a delay of 1/5 of a second but the output file was not even half a second long (but displayed every picture). For setting the framerate I use the time_base option of the AVCodeContext :



ctx->time_base = (AVRational) {1, 5};


When I use the command
ffmpeg -framerate 1/3 -i img%03d.png -codec png output.avieverything works fine and I get the file I want. I use the png codec because it was the only one i tried that is playable with Windows Media Player.


Am I missing anything here ? Is there another option that has impact on the framerate ?



This is my code so far :



Note : I use a couple of self made data structures and methodes from other classes. They are the ones written in Caps Lock. They basicly do what the name suggests but are necessary for my project. The Input Array contains the pictures that i want to encode.



include <libavutil></libavutil>opt.h>
include <libavutil></libavutil>imgutils.h>
include <libavutil></libavutil>error.h>

void PixmapsToAVI (ARRAY* arr, String outfile, double secs)
{
 if (arr!=nil && outfile!="" && secs!=0) {
 AVCodec* codec = avcodec_find_encoder(AV_CODEC_ID_PNG);
 if (codec) {
 int width = -1;
 int height = -1;
 int ret = 0;

 AVCodecContext* ctx = NULL;
 ctx = avcodec_alloc_context3(codec);
 AVFrame* frame = av_frame_alloc();
 AVPacket* pkt = av_packet_alloc();

 FILE* file = fopen(outfile, "wb");

 ARRAYELEMENT* e;
 int count = 0;
 forall (e, *arr) {
 BITMAP bitmap (e->value, false);
 if (width < 0) {
 width = bitmap.Width();
 height = bitmap.Height();

 ctx->width = width;
 ctx->height = height;
 ctx->time_base = (AVRational){1, 5};
 ctx->framerate = (AVRational){5, 1};
 ctx->pix_fmt = AV_PIX_FMT_RGB24;
 ret = avcodec_open2(ctx, codec, NULL);

 frame->width = width;
 frame->height = height;
 frame->format = ctx->pix_fmt;
 av_opt_set(ctx->priv_data, "preset", "slow", 1);

 }
 ret = av_frame_get_buffer(frame, 1);
 frame->linesize[0] = width*3;

 bitmap.Convert32();
 byte* pixels = bitmap.PixelsRGB(); 

//The two methodes above convert the Pixmap into the RGB structure we need
//They are not needed to get an output file but are needed to get one that makes sense

 fflush(stdout);
 int writeable = av_frame_make_writable(frame);
 if (writeable>=0) {
 for(int i=0; i<(height*width*3); i++){
 frame->data[0][i] = pixels[i];
 }
 }
 ret = avcodec_send_frame(ctx, frame);
 for(int i=0; i= 0) {
 ret = avcodec_receive_packet(ctx, pkt);
 }
 count++;
 avcodec_receive_packet(ctx, pkt);
 fwrite(pkt->data, 1, pkt->size, file);
 fflush(stdout);
 av_packet_unref(pkt);
 }
 fclose(file);
 avcodec_free_context(&ctx);
 av_frame_free(&frame);
 av_packet_free(&pkt);

 }
 }
} 








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How to explain the given ffplay C code snippet ?
20 juillet 2015, par Jerikc XIONGThe following code snippet is from ffplay :
static int decoder_decode_frame(Decoder *d, AVFrame *frame, AVSubtitle *sub) {
int got_frame = 0;
do {
int ret = -1;
if (d->queue->abort_request)
return -1;
if (!d->packet_pending || d->queue->serial != d->pkt_serial) {
AVPacket pkt;
do {
if (d->queue->nb_packets == 0)
SDL_CondSignal(d->empty_queue_cond);
if (packet_queue_get(d->queue, &pkt, 1, &d->pkt_serial) < 0)
return -1;
if (pkt.data == flush_pkt.data) {
avcodec_flush_buffers(d->avctx);
d->finished = 0;
d->next_pts = d->start_pts;
d->next_pts_tb = d->start_pts_tb;
}
} while (pkt.data == flush_pkt.data || d->queue->serial != d->pkt_serial);
av_free_packet(&d->pkt);
d->pkt_temp = d->pkt = pkt;
d->packet_pending = 1;
}
switch (d->avctx->codec_type) {
case AVMEDIA_TYPE_VIDEO:
ret = avcodec_decode_video2(d->avctx, frame, &got_frame, &d->pkt_temp);
if (got_frame) {
if (decoder_reorder_pts == -1) {
frame->pts = av_frame_get_best_effort_timestamp(frame);
} else if (decoder_reorder_pts) {
frame->pts = frame->pkt_pts;
} else {
frame->pts = frame->pkt_dts;
}
}
break;
case AVMEDIA_TYPE_AUDIO:
ret = avcodec_decode_audio4(d->avctx, frame, &got_frame, &d->pkt_temp);
if (got_frame) {
AVRational tb = (AVRational){1, frame->sample_rate};
if (frame->pts != AV_NOPTS_VALUE)
frame->pts = av_rescale_q(frame->pts, d->avctx->time_base, tb);
else if (frame->pkt_pts != AV_NOPTS_VALUE)
frame->pts = av_rescale_q(frame->pkt_pts, av_codec_get_pkt_timebase(d->avctx), tb);
else if (d->next_pts != AV_NOPTS_VALUE)
frame->pts = av_rescale_q(d->next_pts, d->next_pts_tb, tb);
if (frame->pts != AV_NOPTS_VALUE) {
d->next_pts = frame->pts + frame->nb_samples;
d->next_pts_tb = tb;
}
}
break;
case AVMEDIA_TYPE_SUBTITLE:
ret = avcodec_decode_subtitle2(d->avctx, sub, &got_frame, &d->pkt_temp);
break;
}
if (ret < 0) {
d->packet_pending = 0;
} else {
d->pkt_temp.dts =
d->pkt_temp.pts = AV_NOPTS_VALUE;
if (d->pkt_temp.data) {
if (d->avctx->codec_type != AVMEDIA_TYPE_AUDIO)
ret = d->pkt_temp.size;
d->pkt_temp.data += ret;
d->pkt_temp.size -= ret;
if (d->pkt_temp.size <= 0)
d->packet_pending = 0;
} else {
if (!got_frame) {
d->packet_pending = 0;
d->finished = d->pkt_serial; // FLAG
}
}
}
} while (!got_frame && !d->finished);
return got_frame;
}It’s difficult for me to understand the following code :
d->finished = d->pkt_serial; // FLAGCan anyone help me ?
Thanks.
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doc/ffmpeg : Use @code
29 juillet 2015, par Michael Niedermayer
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