Recherche avancée

Sur d’autres sites (3062)

• Piping ppm files to ffmpeg to create movie in c++

  15 août 2015, par chasep255

  I want to create a movie of a zoom on the Mandelbrot set. To do this I want to create image data in the ppm format and then pipe it into ffmpeg using popen. The following command works if I first save the ppm to my disc and then run ffmpeg through the terminal.

  ffmpeg -i out.ppm -r 1/5 out.mp4

  Here is what I am trying to do in code.

  FILE* p = popen("ffmpeg -i /dev/stdin -r 1/5 out.mp4", "w");
  
  ppm_pipe(p, pix_buffers[0], w, h);
  
  fclose(p);
  
  ...
  
  void ppm_pipe(FILE* f, unsigned char* pix, int w, int h)
  
  {
  
      assert(fprintf(f, "P6 %d %d 255\n", w, h) > 0);
  
      size_t sz = 3 * (size_t)w * (size_t)h;
  
      assert(fwrite(pix, 1, sz, f) == sz);
  
  }

  I get the following error message.

  ffmpeg version 2.5.8-0ubuntu0.15.04.1 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.9.2 (Ubuntu 4.9.2-10ubuntu13)
  
    configuration: --prefix=/usr --extra-version=0ubuntu0.15.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --shlibdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --enable-shared --disable-stripping --enable-avresample --enable-avisynth --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libshine --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libwavpack --enable-libwebp --enable-libxvid --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzvbi --enable-libzmq --enable-frei0r --enable-libvpx --enable-libx264 --enable-libsoxr --enable-gnutls --enable-openal --enable-libopencv --enable-librtmp --enable-libx265
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.102 / 56. 15.102
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  /dev/stdin: Invalid data found when processing input

• How to create a fixed image video with ffmpeg that avoids pixelization when it's not maximized ?

  11 août 2022, par Nelson Teixeira

  I have a waiting video in the project I develop. This video is a fixed waiting image with music. I was asked to change the image in the video due to deprecated logo.

  


  So initially I tried just to replace the image in the video using this command :

  


  ffmpeg -i old_waiting_video.mp4 -i new_image.png -filter_complex "[1][0]scale2ref[i][v];[v][i]overlay" -c:a copy new_waiting_video.mp4


  


  This lead to the image became pixelated when the video isn't maximized. When maximized the image is OK. But it looks terrible in the small player.

  


  Here is an image of the problem :

  


  

  


  The above image is the image without zoom out. The left bottom image is a screen capture when I resize it in an image tool and the right bottom is a screen capture of how it looks like in the player.
The image has more than this text, but I thought that wouldn't be appropriate to display my company's logo here. The logo itself is even more pixelized and looks terrible.

  


  So to try to solve this problem I extracted the audio from the file and try to add the image and the audio together to see if it removed the pixelization. So I used this command :

  


  ffmpeg -i audio.m4a -i new_image.png new_waiting_video.mp4


  


  When it failed, searching a bit I came across this other command :

  


  ffmpeg -loop 1 -i new_image.png -i audio.m4a -c:v libx264 -tune stillimage -c:a copy -pix_fmt yuv420p -shortest new_waiting_video.mp4


  


  Again the pixelization ocurred. I know it's possible because this problem doesn't occur in the old logo.

  


  What would be the correct command that allowed that the zoomed out image in the player doesn't pixelate ?

  


  Edit 1

  


  I would also be interested in a command that substitutes the image on the old video as long it doesn't pixelate in the non-maximized player.

  


  Edit 2

  


  

  • Video resolution : 1920x1080

  


  • New image resolution : 1920x1080

  


  • Non-maximized video player size : 640x360

  


  • Video tag : <video src="my-video-url.mp4" style="width: 640px;"></video>

  


  


• Evolution #4271 (Nouveau) : valider_url_distante => pouvoir déclarer des domaines distants et pas ...

  21 janvier 2019, par - Equipement

  Bonjour,

  La fonction valider_url_distante permet de déclarer des hosts distants :
  

  <span class="CodeRay"><span class="local-variable">$known_hosts</span> = pipeline(<span class="string"><span class="delimiter">'</span><span class="content">declarer_hosts_distants</span><span class="delimiter">'</span></span>, <span class="local-variable">$known_hosts</span>);
  </span>
  Télécharger

  C’est très bien, mais avec plusieurs centaines de hosts à déclarer (dont la liste varie dans le temps), cela devient compliqué à gérer.

  Serait-il possible d’avoir, en plus, la possibilité de déclarer des domaines distants ?

  Une première piste serait de pouvoir déclarer .example.com dans le pipeline pour inclure tous les *.example.com au lieu des les énumérer un par un.

  Une seconde piste consisterait à s’inspirer de la function need_proxy (via une constante avec la même syntaxe que pour le http_noproxy) :

  // Pour mémoire code actuel à conserver ...
  

  <span class="CodeRay">    <span class="local-variable">$is_known_host</span> = <span class="predefined-constant">false</span>;
      <span class="keyword">foreach</span> (<span class="local-variable">$known_hosts</span> <span class="keyword">as</span> <span class="local-variable">$known_host</span>) {
          <span class="local-variable">$parse_known</span> = <span class="predefined">parse_url</span>(<span class="local-variable">$known_host</span>);
          <span class="keyword">if</span> (<span class="local-variable">$parse_known</span>
            <span class="keyword">and</span> <span class="predefined">strtolower</span>(<span class="local-variable">$parse_known</span>[<span class="string"><span class="delimiter">'</span><span class="content">host</span><span class="delimiter">'</span></span>]) === <span class="predefined">strtolower</span>(<span class="local-variable">$parsed_url</span>[<span class="string"><span class="delimiter">'</span><span class="content">host</span><span class="delimiter">'</span></span>])) {
              <span class="local-variable">$is_known_host</span> = <span class="predefined-constant">true</span>;
              <span class="keyword">break</span>;
          }
      }
  </span>
  Télécharger

  // ... que l’on pourrait faire suivre de ce code (complètement inspiré de function need_proxy) :
  

  <span class="CodeRay">    <span class="keyword">if</span> (!<span class="local-variable">$is_known_host</span>) {
                  <span class="local-variable">$known_domaines</span> = _DECLARER_DOMAINES_DISTANTS;
   
                  <span class="local-variable">$known_domaines</span> = <span class="predefined">str_replace</span>(<span class="string"><span class="delimiter">"</span><span class="char">\n</span><span class="delimiter">"</span></span>, <span class="string"><span class="delimiter">"</span><span class="content"> </span><span class="delimiter">"</span></span>, <span class="local-variable">$known_domaines</span>);
                  <span class="local-variable">$known_domaines</span> = <span class="predefined">str_replace</span>(<span class="string"><span class="delimiter">"</span><span class="char">\r</span><span class="delimiter">"</span></span>, <span class="string"><span class="delimiter">"</span><span class="content"> </span><span class="delimiter">"</span></span>, <span class="local-variable">$known_domaines</span>);
                  <span class="local-variable">$known_domaines</span> = <span class="string"><span class="delimiter">"</span><span class="content"> </span><span class="local-variable">$known_domaines</span><span class="content"> </span><span class="delimiter">"</span></span>;
                  <span class="local-variable">$domain</span> = <span class="predefined">strtolower</span>(<span class="local-variable">$parsed_url</span>[<span class="string"><span class="delimiter">'</span><span class="content">host</span><span class="delimiter">'</span></span>]);
   
                  <span class="keyword">if</span> (<span class="predefined">strpos</span>(<span class="local-variable">$known_domaines</span>, <span class="string"><span class="delimiter">"</span><span class="content"> </span><span class="local-variable">$domain</span><span class="content"> </span><span class="delimiter">"</span></span>) !== <span class="predefined-constant">false</span>){
                      <span class="local-variable">$is_known_host</span> = <span class="predefined-constant">true</span>;
                  }
   
                  <span class="keyword">while</span> (<span class="predefined">strpos</span>(<span class="local-variable">$domain</span>, <span class="string"><span class="delimiter">'</span><span class="content">.</span><span class="delimiter">'</span></span>) !== <span class="predefined-constant">false</span>) {
                          <span class="local-variable">$domain</span> = <span class="predefined">explode</span>(<span class="string"><span class="delimiter">'</span><span class="content">.</span><span class="delimiter">'</span></span>, <span class="local-variable">$domain</span>);
                          <span class="predefined">array_shift</span>(<span class="local-variable">$domain</span>);
                          <span class="local-variable">$domain</span> = <span class="predefined">implode</span>(<span class="string"><span class="delimiter">'</span><span class="content">.</span><span class="delimiter">'</span></span>, <span class="local-variable">$domain</span>);
   
                          <span class="keyword">if</span> (<span class="predefined">strpos</span>(<span class="local-variable">$known_domaines</span>, <span class="string"><span class="delimiter">"</span><span class="content"> .</span><span class="local-variable">$domain</span><span class="content"> </span><span class="delimiter">"</span></span>) !== <span class="predefined-constant">false</span>) {
                              <span class="local-variable">$is_known_host</span> = <span class="predefined-constant">true</span>;
                          }
                  }
          } 
  </span>
  Télécharger

  Cordialement
  Equipement