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La conservation du net art au musée. Les stratégies à l’œuvre
26 mai 2011
Mis à jour : Juillet 2013
Langue : français
Type : Texte
Autres articles (51)
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Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
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Les notifications de la ferme
1er décembre 2010, parAfin d’assurer une gestion correcte de la ferme, il est nécessaire de notifier plusieurs choses lors d’actions spécifiques à la fois à l’utilisateur mais également à l’ensemble des administrateurs de la ferme.
Les notifications de changement de statut
Lors d’un changement de statut d’une instance, l’ensemble des administrateurs de la ferme doivent être notifiés de cette modification ainsi que l’utilisateur administrateur de l’instance.
À la demande d’un canal
Passage au statut "publie"
Passage au (...) -
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 (8270)
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FFmpeg batchfile to compress images JPG JPEGs and keep EXIF (metadata)
24 novembre 2023, par esdoublelefI tried searching everywhere for a possible solution but I really can't find it. Hope someone can help me out here.


I have written a batch file to use FFmpeg to compress and sharpen JPGs in a folder.


@ECHO ON
 FOR %%a in (*.jpg) DO (ffmpeg -i "%%a" -q:v 8 -vf unsharp=5:5:1.0:5:5:0.0 "2022 01 22 %%~na".jpg)
PAUSE



The new file comes out smaller in size, but is missing all the EXIF information that the original photo has.


I tried to add in the command
-metadata
but apparently it works for MP4 only. I have an existing solution with ImageMagick but I'm hoping to solve this via FFmpeg.

Or is there a way to integrate exiftool into the batch file ?


Thank you and I really appreciate any help here.


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Latest FFmpeg fails to create a good MP4 out of JPG file (Windows 10)
30 décembre 2023, par mengrieI am using FFmpeg to create an MP4 file out of several JPG files. The command to accomplish this


ffmpeg.exe ^
-hide_banner -nostats -loglevel error -y ^
-loop 1 -t 6 -i 001.jpg ^
-loop 1 -t 6 -i 002.jpg ^
-loop 1 -t 6 -i 003.jpg ^
-loop 1 -t 6 -i 004.jpg ^
-loop 1 -t 6 -i 005.jpg ^
-loop 1 -t 6 -i 006.jpg ^
-filter_complex ^
"[0:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1,fade=t=out:st=5:d=1[v0]; ^
[1:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1,fade=t=in:st=0:d=1,fade=t=out:st=5:d=1[v1]; ^
[2:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1,fade=t=in:st=0:d=1,fade=t=out:st=5:d=1[v2]; ^
[3:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1,fade=t=in:st=0:d=1,fade=t=out:st=5:d=1[v3]; ^
[4:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1,fade=t=in:st=0:d=1,fade=t=out:st=5:d=1[v4]; ^
[5:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1,fade=t=in:st=0:d=1,fade=t=out:st=5:d=1[v5]; ^
[v0][v1][v2][v3][v4][v5]concat=n=6:v=1:a=0,format=yuv420p[v]" -map "[v]" -r 30 006.mp4



Using "ffmpeg version 2022-12-25-git-eeb280f351-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers built with gcc 12.1.0 (Rev2, Built by MSYS2 project)" does the job as expected.


However, yesterdag I downloaded (from gyan.dev - Windows - ffmpeg-git-full.7z) the latest version and upgrade the tool. "ffmpeg version 2023-12-28-git-c1340f3439-full_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developers built with gcc 12.2.0 (Rev10, Built by MSYS2 project)"


Using this version, the MP4 contains only a few JPGs and timing is also messed up, resulting in a useless MP4.


Has something changed or are these parameters causing a new behaviour ?


Thx


In meanwhile I went back to older version


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Exception thrown at 0x00007FFC0B57BCEF (swscale-6.dll) in App.exe : 0xC0000005 : Access violation reading location 0xFFFFFFFFFFFFFFFF
9 novembre 2023, par JIUN-YUTrying to play a video using FFmpeg on visual studio 2022 on windows 10.
Exception is thrown at sws_scale in the code. Don't know why this is occurred.
It is worth noting that this error sometimes occurs when reading the camera and sometimes it does not.


here is my code


bool CalibrationPanel::video_reader_read_frame(VReaderState* state, cv::Mat cvimg)
{
 // Unpack members of state
 auto& width = state->width;
 auto& height = state->height;
 auto& av_format_ctx = state->av_format_ctx;
 auto& av_codec_ctx = state->av_codec_ctx;
 auto& video_stream_index = state->video_stream_index;
 auto& av_frame = state->av_frame;
 auto& av_packet = state->av_packet;
 auto& sws_scaler_ctx = state->sws_scaler_ctx;


 // Decode one frame
 int response;
 while (av_read_frame(av_format_ctx, av_packet) >= 0)
 {
 if (av_packet->stream_index != video_stream_index)
 {
 av_packet_unref(av_packet);
 continue;
 }

 response = avcodec_send_packet(av_codec_ctx, av_packet);
 if (response < 0)
 {
 char errStr[256] = {0};
 av_strerror(response, errStr, sizeof(errStr));
 printf("Failed to decode packet: %s\n", errStr);
 return false;
 }

 response = avcodec_receive_frame(av_codec_ctx, av_frame);
 if (response == AVERROR(EAGAIN) || response == AVERROR_EOF)
 {
 av_packet_unref(av_packet);
 continue;
 }
 else if (response < 0)
 {
 char errStr[256] = {0};
 av_strerror(response, errStr, sizeof(errStr));
 printf("Failed to decode packet: %s\n", errStr);
 return false;
 }

 av_packet_unref(av_packet);
 break;
 }
 int64_t* pts = &ppts;
 *pts = av_frame->pts;

 // Set up sws scaler
 if (!sws_scaler_ctx)
 {
 sws_scaler_ctx = sws_getContext(width, height, av_codec_ctx->pix_fmt,
 width, height, AV_PIX_FMT_BGR24,
 SWS_BILINEAR, NULL, NULL, NULL);
 if (!sws_scaler_ctx)
 {
 printf("Couldn't initialize sw scaler\n");
 return false;
 }
 }


 // Creating an image space to hold YUV images
 AVFrame* frameYUV = av_frame_alloc();
 auto* out_buffer = (unsigned char*)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_BGR24, width, height, 1));
 av_image_fill_arrays(frameYUV->data, frameYUV->linesize, (const uint8_t*)out_buffer, AV_PIX_FMT_BGR24, width, height, 1);

 uint8_t* dest[4] = {cvimg.data, NULL, NULL, NULL};
 sws_scale(sws_scaler_ctx, av_frame->data, av_frame->linesize, 0, av_frame->height, dest, frameYUV->linesize);

 return true;
}



fixed this bug, so it's not luck that makes the camera turn on every time.