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Autres articles (39)
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Selection of projects using MediaSPIP
2 mai 2011, parThe examples below are representative elements of MediaSPIP specific uses for specific projects.
MediaSPIP farm @ Infini
The non profit organizationInfini develops hospitality activities, internet access point, training, realizing innovative projects in the field of information and communication technologies and Communication, and hosting of websites. It plays a unique and prominent role in the Brest (France) area, at the national level, among the half-dozen such association. Its members (...) -
L’espace de configuration de MediaSPIP
29 novembre 2010, parL’espace de configuration de MediaSPIP est réservé aux administrateurs. Un lien de menu "administrer" est généralement affiché en haut de la page [1].
Il permet de configurer finement votre site.
La navigation de cet espace de configuration est divisé en trois parties : la configuration générale du site qui permet notamment de modifier : les informations principales concernant le site (...) -
Installation en mode ferme
4 février 2011, parLe mode ferme permet d’héberger plusieurs sites de type MediaSPIP en n’installant qu’une seule fois son noyau fonctionnel.
C’est la méthode que nous utilisons sur cette même plateforme.
L’utilisation en mode ferme nécessite de connaïtre un peu le mécanisme de SPIP contrairement à la version standalone qui ne nécessite pas réellement de connaissances spécifique puisque l’espace privé habituel de SPIP n’est plus utilisé.
Dans un premier temps, vous devez avoir installé les mêmes fichiers que l’installation (...)
Sur d’autres sites (6262)
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"wrong sample count" When reading MP4 files using OpenCV
26 octobre 2022, par Object UnknownI want to marge some mp4 videos using OpenCV library, but when I try to read those videos using
cv::VideoCapture, it outputs like that :

[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9AAE9D80] co located POCs unavailable
[h264 @ 000001EB9AAE7D80] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9A128600] co located POCs unavailable
[h264 @ 000001EB9A129840] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB9AA28E40] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9A169B00] co located POCs unavailable
[h264 @ 000001EB9A16B680] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB960CD680] co located POCs unavailable
[h264 @ 000001EB960CC8C0] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9A81DDC0] co located POCs unavailable
[h264 @ 000001EB9A81B000] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB960CB200] co located POCs unavailable
[h264 @ 000001EB960CBFC0] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB99F206C0] co located POCs unavailable
[h264 @ 000001EB99F20B40] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9A81D480] co located POCs unavailable
[h264 @ 000001EB9A81B000] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9AD02C00] co located POCs unavailable
[h264 @ 000001EB9AD02300] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9A81B480] co located POCs unavailable
[h264 @ 000001EB9A81B940] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[h264 @ 000001EB9AD02780] co located POCs unavailable
[h264 @ 000001EB9AD01E40] co located POCs unavailable
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001EB96084B80] wrong sample count


and just exited with exit value 0. I want to know why it is reporting this and how to solve it please.


Heres my demo code :


#include <string>
#include <iostream>
#include <opencv2></opencv2>core/core.hpp>
#include <opencv2></opencv2>video/video.hpp>
#include <opencv2></opencv2>imgproc/imgproc.hpp>
#include <opencv2></opencv2>videoio/videoio.hpp>
#include <opencv2></opencv2>highgui/highgui.hpp>

int main()
{
 cv::Mat frame;
 cv::VideoCapture vcap;
 for (int i = 1; i <= 60; i++)
 {
 if (!vcap.open("G:\\Users\\15819\\Desktop\\Demo\\demo (" + std::to_string(i) + ").mp4"))
 {
 std::cout << "Failed to Open File: demo (" << i << ").mp4" << std::endl;
 continue;
 }
 while (!vcap.read(frame))
 cv::imshow("video", frame);
 }
 return 0;
}
</iostream></string>

I installed the
OpenCVandFFmpeglibrary usingvcpkg, here's the library information (displayed byvcpkg listcommand) :

ffmpeg:x64-windows 4.4.1#21 a library to decode, encode, transcode, mux, dem...
ffmpeg:x86-windows 4.4.1#21 a library to decode, encode, transcode, mux, dem...
ffmpeg[avcodec]:x64-windows Build the avcodec library
ffmpeg[avcodec]:x86-windows Build the avcodec library
ffmpeg[avdevice]:x64-windows Build the avdevice library
ffmpeg[avdevice]:x86-windows Build the avdevice library
ffmpeg[avfilter]:x64-windows Build the avfilter library
ffmpeg[avfilter]:x86-windows Build the avfilter library
ffmpeg[avformat]:x64-windows Build the avformat library
ffmpeg[avformat]:x86-windows Build the avformat library
ffmpeg[openh264]:x64-windows H.264 de/encoding via openh264
ffmpeg[openh264]:x86-windows H.264 de/encoding via openh264
ffmpeg[swresample]:x64-windows Build the swresample library
ffmpeg[swresample]:x86-windows Build the swresample library
ffmpeg[swscale]:x64-windows Build the swscale library
ffmpeg[swscale]:x86-windows Build the swscale library
opencv4:x64-windows 4.6.0#6 computer vision library
opencv4:x86-windows 4.6.0#6 computer vision library
opencv4[default-features]:x64-windows Platform-dependent default features
opencv4[default-features]:x86-windows Platform-dependent default features
opencv4[dnn]:x64-windows Enable dnn module
opencv4[dnn]:x86-windows Enable dnn module
opencv4[ffmpeg]:x64-windows ffmpeg support for opencv
opencv4[ffmpeg]:x86-windows ffmpeg support for opencv
opencv4[jpeg]:x64-windows JPEG support for opencv
opencv4[jpeg]:x86-windows JPEG support for opencv
opencv4[png]:x64-windows PNG support for opencv
opencv4[png]:x86-windows PNG support for opencv
opencv4[qt]:x64-windows Qt GUI support for opencv
opencv4[qt]:x86-windows Qt GUI support for opencv
opencv4[quirc]:x64-windows Enable QR code module
opencv4[quirc]:x86-windows Enable QR code module
opencv4[tiff]:x64-windows TIFF support for opencv
opencv4[tiff]:x86-windows TIFF support for opencv
opencv4[webp]:x64-windows WebP support for opencv
opencv4[webp]:x86-windows WebP support for opencv
opencv:x64-windows 4.6.0 Computer vision library
opencv:x86-windows 4.6.0 Computer vision library
opencv[default-features]:x64-windows Platform-dependent default features
opencv[default-features]:x86-windows Platform-dependent default features
opencv[dnn]:x64-windows Enable dnn module
opencv[dnn]:x86-windows Enable dnn module
opencv[jpeg]:x64-windows JPEG support for opencv
opencv[jpeg]:x86-windows JPEG support for opencv
opencv[png]:x64-windows PNG support for opencv
opencv[png]:x86-windows PNG support for opencv
opencv[quirc]:x64-windows Enable QR code module
opencv[quirc]:x86-windows Enable QR code module
opencv[tiff]:x64-windows TIFF support for opencv
opencv[tiff]:x86-windows TIFF support for opencv
opencv[webp]:x64-windows WebP support for opencv
opencv[webp]:x86-windows WebP support for opencv


Other Environments :


OS: Windows 11 x64 Professional Workstation
IDE: Visual Studio 2022
Project C++ Standard: C++14
Project Platform: x64 Release


-
Why convert wav to mp3 get different length
13 avril 2022, par sybilI use NAudio and NAudio.Lame to convert a wav file to mp3 file,code like that :


using var reader = new WaveFileReader(file);
using var ms = new MemoryStream();
var writer = new LameMP3FileWriter(ms, reader.WaveFormat, 32);
reader.CopyTo(writer);
writer.Flush();
File.WriteAllBytes(file.Replace("wav", "mp3"), ms.ToArray());


the wav file length is 1500ms,but the mp3 file length is 1557ms.


And I do the same thing by using ffmpeg.exe,command like that :


ffmpeg -i c:\2\xxx.wav c:\2\xxx.mp3


the output info :


ffmpeg version 5.0.1-essentials_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
 built with gcc 11.2.0 (Rev7, Built by MSYS2 project)
 configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-zlib --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-sdl2 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libgme --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libtheora --enable-libvo-amrwbenc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-librubberband
 libavutil 57. 17.100 / 57. 17.100
 libavcodec 59. 18.100 / 59. 18.100
 libavformat 59. 16.100 / 59. 16.100
 libavdevice 59. 4.100 / 59. 4.100
 libavfilter 8. 24.100 / 8. 24.100
 libswscale 6. 4.100 / 6. 4.100
 libswresample 4. 3.100 / 4. 3.100
 libpostproc 56. 3.100 / 56. 3.100
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, wav, from 'c:\2\xxx.wav':
 Duration: 00:00:01.50, bitrate: 768 kb/s
 Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono, s16, 768 kb/s
Stream mapping:
 Stream #0:0 -> #0:0 (pcm_s16le (native) -> mp3 (libmp3lame))
Press [q] to stop, [?] for help
Output #0, mp3, to 'c:\2\xxx.mp3':
 Metadata:
 TSSE : Lavf59.16.100
 Stream #0:0: Audio: mp3, 48000 Hz, mono, s16p
 Metadata:
 encoder : Lavc59.18.100 libmp3lame
size= 12kB time=00:00:01.51 bitrate= 66.2kbits/s speed= 137x
video:0kB audio:12kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.928711%


And I get a mp3 file which length is 1536ms.
So,why the length changed ?
Thanks for reading.


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How correctly show video with transparency in Qt with OpenCV + FFMpeg
11 avril 2022, par TheEnigmistI'm trying to show a video with transparency in a Qt6 application using OpenCV + FFMPEG.
Actually those are tool versions :


- 

- Win 11
- Qt 6.3.0
- OpenCV 4.5.5 (built with CMake)
- FFMPEG 2022-04-03-git-1291568c98-full_build-www.gyan.dev










I've used a base .mov video with transparency as test (link provided below).
First of all I've converted .mov video to .webm video (VP9) and I see in output text that alpha channel remains




ffmpeg -i '.\Retro Bars.mov' -c:v libvpx-vp9 -crf 30 -b:v 0 output.webm




Input #0, mov,mp4,m4a,3gp,3g2,mj2,
 ...
 Stream #0:0[0x1](eng): Video: qtrle (rle / 0x20656C72), argb(progressive),
 ...

Output #0, webm, 
 ...
 Stream #0:0(eng): Video: vp9, yuva420p(tv, progressive),
 ...


But when I show info of output file with ffmpeg it loses alpha channel :




ffmpeg -i .\output.webm




Input #0, matroska,webm,
 ...
 Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv, progressive),
 ...


If I open output.webm with OBS it is shown correctly without a background, as shown in picture :



If I try to open it with OpenCV + FFMPEG it shows a black background under bars, as shown in picture :



This is how I load video in Qt :


cv::VideoCapture capture;
capture.open(filename, cv::CAP_FFMPEG);
capture.set(cv::CAP_PROP_CONVERT_RGB, false); // try forcing load alpha channel
... //in a thread
while (capture.read(frame)) {
 qDebug() << "c" << frame.channels() << "t" << frame.type() << "d" << frame.depth(); // output: c 3 t 16 d 0
 cv::cvtColor(frame, frame, cv::COLOR_BGR2RGBA); //useless since no alpha channel is detected
 img = QImage(frame.data, frame.cols, frame.rows, QImage::Format_RGBA8888);
 emit processedImage(img); // to show image in a QLabel with QPixmap::fromImage(img)
}


I think the problem is when I load the video with OpenCV, it doens't detect alpha channel, since I can load correctly in other player (obs, html5, etc.)


What I'm wrong with all process to show this video in Qt with transparency ?


EDIT : Added dropbox link with test video + ffmpeg outputs :
sample items


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