Update README: Warn users about unsupported dependency versions in Linux package managers

[duoduo70]

This pull request updates the README to inform users about a potential issue with Linux package managers automatically installing newer versions of dependencies that are not supported by the software. By adding this information, we aim to prevent compatibility issues and improve user experience when setting up the software on Linux systems. I noticed several issues raised by users reporting similar problems (ERROR -9998), which also occurred on my machine. The error message was vague, and it took some time to identify the root cause. This issue seems more prevalent in aggressive package managers like those in ArchLinux.

[homelab-00]

Correct me if I'm wrong here, but your changes are only about ffmpeg which in my experience isn't actually needed to run. I had ffmpeg 7 installed on my windows machine (which IIRC isn't supported by pytorch yet) and while I got warnings (even when I installed ffmpeg 6 or ffmpeg 5) the script still ran fine.

I do agree with your overall point though, in that some packages need to be a specific version (or range of versions) and not the latest for the script to run properly. Learned it the hard way by mindlessly doing conda update --all.

[duoduo70]

even when I installed ffmpeg 6 or ffmpeg 5

Based on my testing, the script runs smoothly when both FFmpeg7 and FFmpeg6 are installed, but fails if only FFmpeg7 is present. On my Linux system, the script attempts to load libavutil.so.58 (FFmpeg6), libavutil.so.57 (FFmpeg5), and libavutil.so.56 (FFmpeg4) simultaneously, but doesn't try to load libavutil.so.59 (FFmpeg7). I can't speak to how it behaves on Windows, as I don't use that.

Also I don't know how to run the program without FFmpeg