
Recherche avancée
Autres articles (52)
-
Gestion générale des documents
13 mai 2011, parMédiaSPIP ne modifie jamais le document original mis en ligne.
Pour chaque document mis en ligne il effectue deux opérations successives : la création d’une version supplémentaire qui peut être facilement consultée en ligne tout en laissant l’original téléchargeable dans le cas où le document original ne peut être lu dans un navigateur Internet ; la récupération des métadonnées du document original pour illustrer textuellement le fichier ;
Les tableaux ci-dessous expliquent ce que peut faire MédiaSPIP (...) -
Des sites réalisés avec MediaSPIP
2 mai 2011, parCette page présente quelques-uns des sites fonctionnant sous MediaSPIP.
Vous pouvez bien entendu ajouter le votre grâce au formulaire en bas de page. -
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 (7354)
-
Cropping Square Video using FFmpeg
27 juin 2014, par zorucUpdated
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;}
-
Revision ccef8842d2 : Allow full coeff probability model and cost update This commit moves the simpli
13 août 2014, par Jingning HanChanged Paths :
Modify /vp9/encoder/vp9_speed_features.c
Allow full coeff probability model and cost updateThis 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 msChange-Id : Iecbc7496a68f31fd49fb09f8dfd97c028d675a5d
-
Revision 1e30547984 : Skip mode search based on reference frame consistency This commit enables the e
12 août 2014, par Jingning HanChanged Paths :
Modify /vp9/encoder/vp9_rdopt.c
Skip mode search based on reference frame consistencyThis commit enables the encoder to skip NEARMV and ZEROMV if the
above and left blocks have identical reference frame, and the
current reference is different from that. It reduces the runtime
of speed 3 for test sequences :
bus cif at 1000 kbps 10064 ms -> 9823 ms
pedestrian 1080p at 2000 kbps 193078 ms -> 189559 msThe compression performance is changed by
derf -0.085%
stdhd -0.103%Change-Id : If304f26d42e6412152a84c3dd7b02635c38444f4