Error in complexfilter in fluent-ffmpeg

See more:

ffmpeg

ReactJS

Hi, i have the following complex_filter in a fluent-ffmpeg function :

.complexFilter([
    {
        filter: "volume",
        options: [string], 
        inputs: "1",
        outputs: 'audio',
        eval: 'frame'
    },
    {
        filter: "amix",
        options: 'inputs=2',
        inputs: ["0:a", "audio"]
    }
])

Inside string i have : "if(between(t,6,12.6)+between(t,16.6,29.8)+between(t,33.8,44),0.15,if(between(t,5,6),0.15/(6-5)*(t-5),if(between(t,15.6,16.6),0.15/(16.6-15.6)*(t-15.6),if(between(t,32.8,33.8),0.15/(33.8-32.8)*(t-32.8),if(between(t,12.6,13.6),0.15/(13.6-12.6)*(13.6-t),if(between(t,29.8,30.8),0.15/(30.8-29.8)*(30.8-t),if(between(t,44,45),0.15/(45-44)*(45-t))))))))"

What my function does : It takes in a video and a music. It adds the music in the background and at certain timestamps it lowers the volume over 1s to 15% then stays at 15% for a while and finally it goes back up to 15%. And it does so 3 times.

I get the following error :

Quote:

Error: ffmpeg exited with code 1: Error initializing complex filters.
Invalid argument

What I have tried:

I've checked the number of parantheses and the syntax comes from this post : video.stackexchange.com that i have converted to fluent-ffmpeg.