Maybe these videos will help someone.
Someone who is not definitely decided to use or not to use SubDownloader for downloading and uploading subtitles.
Subdownloader is a Free Open Source tool written in Python for automatically downloading subtitles/uploading subtitles for videofiles (MKV,MP4,AVI,etc) using fast hashing.
If SubDownloader doesn’t work for you, try OSCAR
1. Downloading subtitles
Following video explains how to download subtitles using SubDownloader.
2. Uploading subtitles