Srtedit -

: One of its standout features is the ability to easily manage bilingual or dual-language subtitles. This is frequently used to place two different languages (e.g., Chinese and English) on the screen simultaneously, often with different font styles for each.

pip install srtedit

srtedit is a Python-based command-line utility that lets you manipulate SRT subtitle files programmatically. Common uses include: srtedit