How to get sound from a microphone through ffmpeg, amplify it and send it to a virtual cable?

Question

Audio

Here is a list of devices.

[dshow @ 0000000002ca9360] DirectShow audio devices
[dshow @ 0000000002ca9360]  "╨Ь╨╕╨║╤А╨╛╤Д╨╛╨╜ (Realtek High Definition Audio)"
[dshow @ 0000000002ca9360]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\wave_{B9E6CC62-9748-42D0-B8CF-9E27BB53D9C3}"
[dshow @ 0000000002ca9360]  "CABLE Output (VB-Audio Virtual Cable)"
[dshow @ 0000000002ca9360]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\wave_{BA3025B3-E880-46D4-AEE7-CE59718D816B}"

It is necessary that the sound from the first microphone is amplified by 2 times and transmitted to virtual cable two. My code is not working, says:

Requested output format 'dshow' is not a suitable output format
audio=CABLE Output (VB-Audio Virtual Cable): Invalid argument

ffmpeg -re -f dshow -i audio="@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\wave_{B9E6CC62-9748-42D0-B8CF-9E27BB53D9C3}" -af 'volume=2' -f s16le -acodec pcm_s16le -f dshow audio="CABLE Output (VB-Audio Virtual Cable)"

Answer 1

dshow in its current form is only supported as an Input device. So while to withdraw - no way. You need to write the program yourself and draw the conclusion. For example, as in ffplay - via SDL2. Gain - through a filter, about the same as yours.