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  • MediaSPIP 0.1 Beta version

    25 avril 2011, par

    MediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
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  • MediaSPIP version 0.1 Beta

    16 avril 2011, par

    MediaSPIP 0.1 beta est la première version de MediaSPIP décrétée comme "utilisable".
    Le fichier zip ici présent contient uniquement les sources de MediaSPIP en version standalone.
    Pour avoir une installation fonctionnelle, il est nécessaire d’installer manuellement l’ensemble des dépendances logicielles sur le serveur.
    Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...)

  • Amélioration de la version de base

    13 septembre 2013

    Jolie sélection multiple
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Sur d’autres sites (11782)

  • How correctly show video with transparency in Qt with OpenCV + FFMpeg

    11 avril 2022, par TheEnigmist

    I'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 :
obs_load

    


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

    


    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

    


  • Why convert wav to mp3 get different length

    13 avril 2022, par sybil

    I 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.

    


  • "wrong sample count" When reading MP4 files using OpenCV

    26 octobre 2022, par Object Unknown

    I 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>&#xA;#include <iostream>&#xA;#include <opencv2></opencv2>core/core.hpp>&#xA;#include <opencv2></opencv2>video/video.hpp>&#xA;#include <opencv2></opencv2>imgproc/imgproc.hpp>&#xA;#include <opencv2></opencv2>videoio/videoio.hpp>&#xA;#include <opencv2></opencv2>highgui/highgui.hpp>&#xA;&#xA;int main()&#xA;{&#xA;        cv::Mat frame;&#xA;        cv::VideoCapture vcap;&#xA;        for (int i = 1; i &lt;= 60; i&#x2B;&#x2B;)&#xA;        {&#xA;            if (!vcap.open("G:\\Users\\15819\\Desktop\\Demo\\demo (" &#x2B; std::to_string(i) &#x2B; ").mp4"))&#xA;            {&#xA;                std::cout &lt;&lt; "Failed to Open File: demo (" &lt;&lt; i &lt;&lt; ").mp4" &lt;&lt; std::endl;&#xA;                continue;&#xA;            }&#xA;            while (!vcap.read(frame))&#xA;                cv::imshow("video", frame);&#xA;        }&#xA;        return 0;&#xA;}&#xA;</iostream></string>

    &#xA;

    I installed the OpenCV and FFmpeg library using vcpkg, here's the library information (displayed by vcpkg list command) :

    &#xA;

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

    &#xA;

    Other Environments :

    &#xA;

    OS: Windows 11 x64 Professional Workstation&#xA;IDE: Visual Studio 2022&#xA;Project C&#x2B;&#x2B; Standard: C&#x2B;&#x2B;14&#xA;Project Platform: x64 Release&#xA;

    &#xA;

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