Like every big JAV fan who doesn't understand the Japanese language, I've been looking for ways to get subtitles for the movies I like. This is how I found out about these forums several years ago and this is also how I found out about Subtitle Edit, a great subtitle editing software that is not only free and easy to use, but also great.
I know some people don't like it because depending on how it's used it can sometimes lead to frustrating results. However, I just found a way that, from my point of view, produces results that serve as a good base for further manual editing that produces quality results in an easy and fun way.
I share the steps that I follow, in case someone finds them useful:
1) Download Subtitle Edit from their website:
https://www.nikse.dk/subtitleedit
2) Install and run the application.
3) Choose the option Video/Audio to text (Vosk/Kaldi).
5) Click on the Add... button and choose the video whose subtitles we want to obtain.
7) Click on the Generate button. After a while (usually less than an hour on medium computers), the SRT file of the video with Japanese subtitles will appear in the same folder the video is in.
8) Drag the SRT file onto the Chrome window.
9) Right click on the Chrome window and choose the option Translate to english (or the desired language).
10) Copy the translation and paste it into the SRT file (so that it replaces the previous text).
With this we have the subtitles ready in a low to medium quality, but everything will be ready to manually edit and bring the subtitles to the desired quality.
I hope this helps more than one.