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• Glitchiness when I add transparency to a gif and convert it to webm

  5 avril 2017, par maxple

  Starting off I have this gif from google images :

  

  Then I convert the blue to transparency :

  convert octopus.gif -transparent "#00AEFF" octopus-transparent.gif

  Now I have this (note glitchiness has already started to appear)

  

  Now for the grand finale, I convert it to webm :

  convert octopus-transparent.gif tmp%03d.png
  
  
  
  ffmpeg -framerate 25 -f image2 -i ./tmp%03d.png -c:v libvpx -pix_fmt yuva420p octopus.webm

  See the following screenshot. It is still transparent, but the sizing is no longer steady, and frankly it’s starting to look a little creepy :

  

  I don’t really know much about video codecs and I’ve just got this far with others’ help. I’d appreciate advice as to how I can change these commands to avoid the glitches.

• FFmpeg Drawbox Errors ?

  12 mars 2021, par Alex Gurr

  Using ffmpeg version 4.3.2.

  


  Command :

  


  ffmpeg -y

  -i /usr/src/app/backgrounds/pink-blue.jpg
  -i files/fuzzy-octopus-5/path/file.webm
  -i files/fuzzy-octopus-5/path/file.webm
  -i /usr/src/app/logo.png
  -filter_complex "
    [0]drawbox=x=-140:y=(((H-th)/2) - 205):w=840:h=490:color=white@0.2:t=fill,
       drawbox=x=770:y=(((H-th)/2) - 205):w=840:h=490:color=white@0.2:t=fill[bg]; 
    ...


  


  However I am getting the following errors ?

  


  Error while processing the decoded data for stream #3:0
Failed to inject frame into filter network: Invalid argument
Error reinitializing filters!
[Parsed_drawbox_0 @ 0x564a87058e80] Failed to configure input pad on Parsed_drawbox_0
[Parsed_drawbox_0 @ 0x564a87058e80] Error when evaluating the expression '(((H-th)/2) - 205)'.
Last message repeated 5 times
[Parsed_drawbox_0 @ 0x564a87058e80] [Eval @ 0x7ffcf25dc650] Undefined constant or missing '(' in 'H-th)/2)-205)'


  


  I have the right amount of brackets and this definitely works on my local machine (macOS). It's only throwing this error in our deployed AWS EC2 linux instance.

  


  Any ideas ? Thanks !

  


  Update : Tried replacing th with h but get the same error