Recherche avancée

Sur d’autres sites (10108)

• Black overlay appears when merging a transparent video to another video

  13 juin 2012, par RakeshS

  This is what I have done so far :

  Command to create a transparent PNG image :

  convert -size 640x480 -background transparent -fill blue \
  
  -gravity South label:ROCK image1-0.png

  Command to create a transparent video :

  ffmpeg -loop 1 -f image2 -i image1-0.png -r 20 -vframes 100 \
  
  -vcodec png -pix_fmt bgra mov-1.mov

  (as per this post) - I expect this video to be a transparent video.

  Command to overlay a video with another :

  ffmpeg -i final-video.mov -sameq -ar 44100 \
  
  -vf "movie=mov-1.mov [logo];[in][logo] overlay=0:0 [out]" \
  
  -strict experimental final-video.mov

  Above commands works perfect and I have not faced any problem, but I don't get what I expect which is kinda watermarking effect, I want mov-1.mov to be transparent with final-video.mov.

  Questions :

  1. Is there any way to verify if the generated video is transparent ? other than merging ?
  2. Not sure why the above mov-1.mov is not transparent when it is merged with final-video.mov, any info to solve this problem would be great.

  Please help.

• Why do I get a black box when I tile pictures with -filter_complex tile=2x1 in FFmpeg ?

  19 juin 2016, par Mateusz Piotrowski

  As I was trying to write a script (which attempts to join two pictures eventually) using FFmpeg I came across a very weird behaviour.

  I’ve found a command in an accepted answer for the very same problem I had (How to join two image into one by ffmpeg ?) :

  ffmpeg -i a.jpg -i b.jpg -filter_complex scale=120:-1,tile=2x1 output.jpg

  • Input : a.jpg, b.jpg

    

  • Output : output.jpg

    

  What happened to the B cat ? Why is it missing from the output image ? I couldn’t find any information why tile=2x1 behaves like this.

• FFmpeg : How to convert vertical/horizontal video (any size) with black sides, to 1080x1350 vertical video with blurred background sides/bottom-top

  12 octobre 2023, par devweb

  i've been trying to make a ffmpeg 'filter_complex' code to make what i need but i can't, i've used some codes here on stack but non works for what i need, each is like for a different size/dimension.
I'm trying to make videos like Instagram posts (tallest allowed) : 1080 x 1350

  


  Bassically, horizontal videos with blurred sides or bottom-top.

  


  Any help will be awesome, thanks !

  


  This is the principal which i tried

  


  Something like this :

  


  Example 1
Example 2

  


  Here some codes i tried to worked with and changing stuff :
filter_complex='[0:v]scale=1080*2:1350*2,boxblur=luma_radius=min(h\\,w)/20:luma_power=1:chroma_radius=min(cw\\,ch)/20:chroma_power=1[bg];[0:v]scale=-1:1080[ov];[bg][ov]overlay=(W-w)/2:(H-h)/2,crop=w=1080:h=1350'

  


  filter_complex='[0:v]scale=ih*5/4:-1,crop=h=iw*4/5,gblur=sigma=20[blurred];[blurred][0:v]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2'

  


  filter_complex='[0:v]scale=1080:1350,setsar=1,gblur=sigma=20[blurred];[blurred][0:v]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2'