If you have installed static ffmpeg to /usr/local/bin , remove that installation and install ffmpeg via package management.

You may have made a systerm upgrade ror years and you have an old static ffmpeg, you can get the next error:

ALSA lib ../../src/conf.c:3683:(snd_config_hooks_call) Cannot open shared library libasound_module_conf_pulse.so (/usr/lib/alsa-lib/libasound_module_conf_pulse.so: libasound_module_conf_pulse.so: cannot open shared object file: No such file or directory)
ALSA lib ../../../src/pcm/pcm.c:2642:(snd_pcm_open_noupdate) Unknown PCM hw:0
[alsa @ 0x756e3c0] cannot open audio device hw:0 (No such file or directory)
hw:0: Input/output error

The dirty fix is to make an /usr/lib/alsa-lib folder and make a sympolic link from /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_conf_pulse.so

sudo mkdir -p /usr/lib/alsa-lib/
sudo ln -s /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_conf_pulse.so /usr/lib/alsa-lib/