I'm trying to add watermarks to multiple images using ffmpeg. It works good in the beginning but when I try to change the opacity of the watermark it shows the error as:

[AVFilterGraph @ 0000019b2a655340] Too many inputs specified for the "scale" filter. Error initializing complex filters. Invalid argument

The used code:

for %%a in ("*.jpg") do ffmpeg -i "%%a" -i wm.png -filter_complex "[1]lut=a=val*0.3[a];[0][a][1]scale=iw*0.50:-1[wm];[0][wm]overlay=0:0" -preset ultrafast "post\%%~na.jpg"

CodePudding user response：

If I understand your intent correctly, change

[1]lut=a=val*0.3[a];[0][a][1]scale=iw*0.50:-1[wm];

to

[1]lut=a=val*0.3,scale=iw*0.50:-1[wm];

The watermarked can be scaled directly after the alpha change.