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Autres articles (60)
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Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
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MediaSPIP Core : La Configuration
9 novembre 2010, parMediaSPIP Core fournit par défaut trois pages différentes de configuration (ces pages utilisent le plugin de configuration CFG pour fonctionner) : une page spécifique à la configuration générale du squelettes ; une page spécifique à la configuration de la page d’accueil du site ; une page spécifique à la configuration des secteurs ;
Il fournit également une page supplémentaire qui n’apparait que lorsque certains plugins sont activés permettant de contrôler l’affichage et les fonctionnalités spécifiques (...) -
Creating farms of unique websites
13 avril 2011, parMediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)
Sur d’autres sites (9632)
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Why motion vector extracted from b frames are unchange ?
19 août 2019, par 霍宇琦I am writing c codes to extract motion vectors from b frame in MPEG4(Part2) compressed video format. But some motion vector seems wrong.
I use a raw video clips, using the extract_mvs.c from ffmpeg 4.2. For example if the frame seq is IPBPPBPP.... i can get all the side data for all frame. But when inspecting the mv->src_x, mv->src_y, mv->dst_x, mv->dst_y i find that all the srcs are equal to dsts for some individual frames, there must be sth wrong in it, but i change little from the official code.
//modify from ffmpeg/doc/example/extract_mvs.c:
while(getting frames one by one) {
AVFrameSideData *sd;
video_frame_count++;
//printf("%d", video_frame_count);
if(video_frame_count < 19){
if (frame->pict_type == AV_PICTURE_TYPE_I ) printf("\nI");
if (frame->pict_type == AV_PICTURE_TYPE_B ) printf("B");
if (frame->pict_type == AV_PICTURE_TYPE_P ) printf("P");
sd = av_frame_get_side_data(frame, AV_FRAME_DATA_MOTION_VECTORS);
if (sd) {
const AVMotionVector *mvs = (const AVMotionVector *)sd->data;
for (i = 0; i < sd->size / sizeof(*mvs); i++) {
const AVMotionVector *mv = &mvs[i];
if (mv->dst_x - mv->src_x != 0 || mv->dst_y - mv->src_y != 0) {
printf("%d,%2d,%2d,%2d,%4d,%4d,%4d,%4d,0x%"PRIx64"\n",
video_frame_count, mv->source,
mv->w, mv->h, mv->src_x, mv->src_y,
mv->dst_x, mv->dst_y, mv->flags);
break;
}
}
}
av_frame_unref(frame);
}
}Outputs are :
Input #0, avi, from 'origin.avi':
Duration: 00:00:13.63, start: 0.000000, bitrate: 492 kb/s
Stream #0:0: Video: mpeg4 (DX50 / 0x30355844), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 486 kb/s, 30 fps, 30 tbr, 30 tbn, 30k tbc
Metadata:
title : H:\HumanActionDB\MotionClips\hmdb51_30fps_wBrd_10off_divx\brush_??
framenum,source,blockw,blockh,srcx,srcy,dstx,dsty,flags
[mpeg4 @ 0x55739dc29580] Video uses a non-standard and wasteful way to store B-frames ('packed B-frames'). Consider using the mpeg4_unpack_bframes bitstream filter without encoding but stream copy to fix it.
IP2,-1,16,16, 137, 24, 136, 24,0x0
BP4,-1,16,16, 152, 57, 152, 56,0x0
P5,-1,16,16, 56, 155, 56, 152,0x0
BP7,-1,16,16, 151, 40, 152, 40,0x0
PB9,-1,16,16, 151, 40, 152, 40,0x0
P10,-1,16,16, 152, 39, 152, 40,0x0
P11,-1,16,16, 26, 55, 24, 56,0x0
B12,-1,16,16, 152, 39, 152, 40,0x0
P13,-1,16,16, 152, 39, 152, 40,0x0
P14,-1,16,16, 41, 168, 40, 168,0x0
B15,-1,16,16, 152, 39, 152, 40,0x0
P16,-1,16,16, 153, 39, 152, 40,0x0
PB18,-1,16,16, 168, 55, 168, 56,0x0you can see that the third frame(B) and the sixth, eighth frame(B, P) and the 17th frame (P) can be read, and the data can be extract from them, but
mv->dst_x == mv->src_x && mv->dst_y - mv->src_y
Can someone help me ? Thanks.
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Error trying to stream multiple files - Invalid data found when processing input
14 avril 2020, par xybrekffmpeg -re -stream_loop -1 -i mylist.txt -f mpegts -vcodec copy -acodec copy http://localhost:8081/yoursecret



mylist.txt file contains :



file 'out001.ts'
file 'out002.ts'




up to out327.ts



Here's the output of the above command :



ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg developers
 built with gcc 9.3.1 (GCC) 20200328
 configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
 libavutil 56. 42.102 / 56. 42.102
 libavcodec 58. 77.101 / 58. 77.101
 libavformat 58. 42.100 / 58. 42.100
 libavdevice 58. 9.103 / 58. 9.103
 libavfilter 7. 77.101 / 7. 77.101
 libswscale 5. 6.101 / 5. 6.101
 libswresample 3. 6.100 / 3. 6.100
 libpostproc 55. 6.100 / 55. 6.100
mylist.txt: Invalid data found when processing input




However streaming individual files works :



ffmpeg -re -stream_loop -1 -i out001.ts -f mpegts -vcodec copy -acodec copy http://localhost:8081/yoursecret




I've also tried but also does not work :



ffmpeg -re -stream_loop -1 -i <(for %%i in (*.ts) do @echo file '%%i') -f mpegts -vcodec copy -acodec copy http://localhost:8081/yoursecret



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New FATE Test Coverage System
10 août 2010, par Multimedia Mike — FATE ServerI’ve been feeling a bit scattered for the last week since I was fired from my volunteer position as the FFmpeg QA manager, wondering if there is anything I should attempt to do with the project. It can’t be denied that the new system is working well. But one area I’ve wondered about is test coverage.
Under my old regime I tracked test coverage as a wiki page which was a highly flawed method— tedious and error-prone. There are those 2 adjectives again— tedious and error-prone ; whenever I see those, I search for automation methods. I think that might be more plausible thanks to the new FATE’s tighter integration with the FFmpeg build system.
I don’t think anyone is working on this problem so I wanted to toss out a brainstorm :
- First, run ’ffmpeg -formats’, ’ffmpeg -codecs’, etc. and parse the output to collect a list of all the features (full list : -formats, -codecs, -bsfs, -protocols, -filters, -pix_fmts). Transform these lists into a standardized list of features, e.g.,
"DEVSD ffvhuff Huffyuv FFmpeg variant"
represents features ’decode-video-ffvhuff’, ’encode-video-ffvhuff’, ’ffvhuff-horizband’, and ’ffvhuff-dr1’. - Next, tag each individual test spec with the features that it exercises. E.g., test ’fate-vqa-cc’ exercises features ’demux-wsvqa’, ’decode-video-vqavideo’, and ’decode-audio-adpcm_ima_ws’.
- Finally, compare the data from parts 1 and 2. Print a list of all the features that are not exercised in FATE.
I think a lot of this could be implemented at the GNU make level. Then again, I’m no expert on GNU make syntax so I may be overestimating its capabilities. Or there might be simpler ways to automatically track test coverage stats based on the improved testing infrastructure.
- First, run ’ffmpeg -formats’, ’ffmpeg -codecs’, etc. and parse the output to collect a list of all the features (full list : -formats, -codecs, -bsfs, -protocols, -filters, -pix_fmts). Transform these lists into a standardized list of features, e.g.,