Two audio inputs in FFmpeg have different volumes

Question

I am using the command below in order to capture desktop, speaker and microphone in a C# application:

ffmpeg.exe -y -f dshow 
    -i audio="virtual-audio-capturer":audio="Microphone" 
    -f gdigrab -draw_mouse 0 -framerate 15 
    -i desktop -pix_fmt yuv420p -af "volume=+5dB" output.mp4

But the speaker's volume is much lower than microphone's volume.

how can i keep them in a same volume?

Answer 1

Unfortunately, based on my researches it is not possible.