Recherche avancée

Sur d’autres sites (9084)

• Fastest way to generate thumbnails with FFMPEG

  10 mai 2022, par Pit Digger

  FFMPEG takes 9 minutes for generating thumbnails every 15 seconds of a 3 hour long video. What is fastest way to do this ? I have tried following combinations but its taking same time.

  


  ffmpeg -ss 0.0 -t 10800 -i test.mp4 -an -vsync cfr -vf fps=1000/15000 -s 128x72 -f image2 -c:v png -compression_level 100 temp-%010d.png

ffmpeg -i test.mp4 -f image2 -bt 20M -vf fps=1/15 thumbs/tv%03d.png

ffmpeg -i inputvideo.mp4 -vf "select='not(mod(n,450))',setpts='N/(30*TB)'" -f image2 thumbnail%03d.jpg


  


  https://trac.ffmpeg.org/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video

  


• shell_exec echo'ing too fast or too late

  15 septembre 2016, par root

  So I read throug this article : https://trac.ffmpeg.org/wiki/PHP
  and found this :

  <?php
  
  echo "Starting ffmpeg...\n\n";
  
  echo shell_exec("ffmpeg -i input.avi output.avi >/dev/null 2>/dev/null &");
  
  echo "Done.\n";

  the code works almost perfectly fine, but the only thing that bothers me is, that because the shell_exec is being executed in the background (so there is no loading sign on the tab the whole time) all the echo’s are being executed immediatly. This means, that the "Done" echo is being written before ffmpeg finished its task.

  But when I remove the ’&’ the site does also what it is intended to do but now it waits until the shell_exec is finished until it echo’s out the "Starting ffmpeg..."

  So I kinda have the problem of figuring out how to get to such an order :

  1) echo something
  2) execute commad and wait until its finished.
  3) echo again

  I am a total beginner to php but have experience in programming overall. Please have mercy.

  Thank you for your time !

• How to use libraries ".lib" and ".a" files in GCC

  12 novembre 2022, par Blue Sky

  I have simple C code that uses some functions of libavcodec in FFmpeg. I try to compile the code with GCC (on Windows using MinGW) as follows :

  


  gcc -o mycode mycode.c


  


  But I get a lot of errors like "undefined reference to av_free". I know that these functions are defined in the libraries of FFmpeg. I do access files like avcodec.lib and libavcodec.dll.a, but I don't know how to use them with GCC so that I can compile and make my file. How can I solve this problem ?