sherpa-ncnn/ffmpeg-examples

Fixes for errors

To fix the following error:

Package libavdevice was not found in the pkg-config search path.

please run

sudo apt-get install libavdevice-dev

To fix the following error

Makefile:28: *** FFmpeg version should be n5.1 or above!.  Stop.

please run

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:savoury1/ffmpeg4
sudo add-apt-repository ppa:savoury1/ffmpeg5
sudo apt-get update
sudo apt-get install ffmpeg --reinstall
sudo apt-get install libavutil-dev --reinstall

To fix the following error:

ModuleNotFoundError: No module named 'apt_pkg'

please run:

sudo apt-get install python-apt