Recherche avancée

Sur d’autres sites (8666)

• ffmpeg extract video unable to play

  30 juin 2021, par Khánh Phạm Đình

  I use ffmpeg to stream video and show up the camera's frame to window in the same time according to current code :

  


  file record_video_and_showup.sh

  


  ffmpeg -f v4l2 -framerate 30 -i $1  -c:v libx264 -preset superfast -crf 18 -pix_fmt yuv420p  -c:a libmp3lame -ac 2 -ar 44100 -b:a 128k -f tee  -map 0:v "$2|[f=nut]pipe:" | ffplay -an pipe:


  


  to record video and show up :

  


  ./record_video_and_showup.sh /dev/video0 test.mp4


  


  finally, we get file test.mp4 but can't play it on app such as vlc. When we open it on google chrome, it can run but the start and end time were incorrect.

  


  Can anyone help me ?

  


• How can I create videos from images with transitions in C# ?

  4 septembre 2021, par Kjensen

  Using C# code, I want to take a number of images, add some music and create a video.

  


  I think I can best explain what I want in pseudo-code... :

  


  var video = new Video(1080, 1920); //create a video 1080*1920px 
video.AddFrame("C:\temp\frame01.jpg", 2000); //show frame for 2000ms
video.AddTransition(Transitions.Fade, 500); //fade from first to second frame for 500ms
video.AddFrame("C:\temp\frame02.jpg", 1000); //show frame for 1000ms
video.AddTransition(Transitions.Fade, 500); //fade from second to third frame for 500ms
video.AddFrame("C:\temp\frame03.jpg", 2000); //show frame for 2000ms
video.AddSound("C:\temp\mymusic.mp3"); //added from start of video
video.Save("C:\temp\MyAwesomeVideo.avi", Format.MP4);


  


  Does something like this exist ?

  


  I know there are a couple of older libraries, that can do some stuff with ffmpeg to create slideshows, but I looked at some of them, and they are insanely tricky to get working - and designed for something quite different.

  


  Backstory :

  


  I created a system for a cinema, which every week generates x number of images using movie posters, showtimes etc - and would like to take those images, turn them into a video which will be shared on social media.

  


• video orientation detection in bash

  30 décembre 2014, par Miati

  I need to detect whether videos are recorded in portrait or landscape mode, then transpose those into the correct orientation, in a scripted fashion.

  if [ "$v_orient" ==  "landscape" ]
  
    then
  
      ffmpeg -i file.mp4 -vf "transpose=1" file.ogv
  
    else 
  
      ffmpeg -i file.mp4 file.ogv
  
  fi

  I’ve looked in ffmpeg online documentation and googled around,

  I’ve attempted exiftool

  exiftool -Rotation -Rotate file.mp4

  However, this outputs Rotate : 90 for both landscape & portrait videos I have.

  ---

  How can I detect the video orientation in bash ?