FFmpeg command to record Skype sound and video

I am trying to record my Skype calls using ffmpeg. I need to record audio (pulseaudio) & video (X). But it seems that it is a bit tricky…

For audio recording I want to use my Scarlet 2i4 audio interface that is listed as device number 10 in pulseaudio:

ziga@ziga-laptop:~$ pactl list short cards
2   alsa_card.pci-0000_00_1b.0  module-alsa-card.c
10  alsa_card.usb-Focusrite_Scarlett_2i4_USB-00 module-alsa-card.c

~$ pactl list short sinks
16  alsa_output.usb-Focusrite_Scarlett_2i4_USB-00.analog-surround-40    module-alsa-card.c  s32le 4ch 44100Hz   SUSPENDED

~$ pactl list short sources
24  alsa_output.usb-Focusrite_Scarlett_2i4_USB-00.analog-surround-40.monitor    module-alsa-card.c  s32le 4ch 44100HzSUSPENDED
25  alsa_input.usb-Focusrite_Scarlett_2i4_USB-00.analog-stereo  module-alsa-card.c  s32le 2ch 44100Hz   IDLE

From this I can see that my desired card is a device 10 so I structured my ffmpeg command like this:

ffmpeg \
-f x11grab -s 1920x1080 -probesize 17M -r 30 -i :0.0+0+0 \
-f pulse -ac 2 -device 10 \
-output.mkv

where:

• 2nd line specifies all video input parameters (tested & working)
• 3rd line specifies all audio parameters (not working)

But when I execute the command I get error:

Output #0, pulse, to 'output.mkv':
Output file #0 does not contain any stream

Does anyone have any idea why? How can I record Skype sound?

ADD

@Gyan's suggestion although did not work it pointed me to the right direction.

I used parameter -device instead of -i. The later is an input parameter and if we specify a device number 10 it does not work. We have to specify an input that we can get using pactl list short sources. So we can use source number 25 e.g.:

ffmpeg -f x11grab -s 1920x1080 -probesize 17M -r 30 -i :0.0+0+0 -f pulse -ac 2 -i 25 output.mkv

This runs but it only records one source which is my microphone. It completely ignores e.g Skype, audio player…

If I open pavucontrol when running Skype and my audio player, pavucontroll shows me these application streams:

How do I include "Skype" and "Deadbeef" streams into the recording?