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• Creating a transparent video out of an input video

  28 juillet 2021, par poldown

  I'm trying to create a video with a transparent background out of an input video (with the same dimensions, etc.). I tried several strategies (using the chromakey filter and others) and none worked... I got this far :

  


  ffmpeg -i input.mp4 -filter_complex "color=color=black@0.0,format=yuva420p[bg],[bg][0:v]scale2ref[bg][0v],[bg]drawbox=x=10:y=10:w=100:h=100:color=pink@0.5;[0v]nullsink" -c:v qtrle -an "alpha.mov"


  


  

  • creating a video stream with transparency, and setting a transparent background (black@0.0)

  


  • scaling the transparent video according to the input video

  


  • [for testing purposes : drawing a box over the transparent video. I omitted the part in which I embed subtitles onto the video, for simplicity's sake]

  


  • discarding the input video stream

  


  • removing the audio stream

  


  


  It basically works, but the processing never ends - I can't manage to limit the output video length so it'll match the input video's length...
I've tried using the -shortest option anywhere in the command - with no success.

  


• Merge two video devices into a third device by placing the video next to each other

  14 janvier 2021, par Lennart Van der Goten

  The Situation

  


  I have two webcams (with associated video devices /dev/video0 and /dev/video1). The first webcam generates a resolution of 720p while the other one generates 1080p.

  


  The Task

  


  I would like to create a new video device /dev/video2 that is defined by putting the video from the first webcame next to the one coming from the second webcam.

  


• Overlaying a video, a text and an image on another video using FFMpeg

  11 janvier 2019, par leo

  I want to overlay a video, a text, and an image on another video using FFMpeg but I do not know how can I do that. My scenario like that ;

  Base Video :
  I have a base video which is 2 minutes in length.
  Overlay Videos :
  I have 3 videos which are 7 seconds in length. I am trying to put these files on some specific times for example first : 20 : 27 seconds, second 40:47 seconds, third : 60:67 second as fully covered basic video.

  I have one image and it will be overlaid on base video between 10:15 seconds for a specific position on the base video.
  I have one text and it will be overlaid on base video between 10:15 seconds for a specific position on the base video.

  How can I do that with FFMpeg command ? And Can I do that with one command ?