loose coupling transcription and translation steps

[MaleicAcid]

The steps of transcription and translation currently appear to be relatively tightly coupled. We can see that the subtitles generated by the transcription are processed in the translation step.

# file: openlrc/openlrc.py
def process_translation(base_name, target_lang, transcribed_opt_sub, skip_trans):
    ...
    if skip_trans:
        shutil.copy(transcribed_opt_sub.filename, final_json_path)
        transcribed_opt_sub.filename = final_json_path
        return transcribed_opt_sub
   ...

And finally generated in translation worker.

def translation_worker(self, transcription_queue, target_lang, skip_trans, bilingual_sub):
       ...
        # Handle translation
        final_subtitle = process_translation(base_name, target_lang, transcribed_opt_sub, skip_trans)

        # Generate and move subtitle files
        generate_subtitle_files(final_subtitle, base_name, subtitle_format)
       ...

This seems to violate the SRP.
At the same time, even specified skip trans=True , the translation thread will still be started. Users pay for the additional performance overhead even though they are not using it.

I wish we could decouple the two steps of transcription and translation:
- The translation step no longer processes transcribed files.
- The translation thread is no longer started when skip_trans=False is specified.

I am not familiar with nlp related knowledge. But if you agree, maybe I can try to complete this improvement.

[zh-plus]

Thank you for this detailed analysis.

I do think the structure of openlrc.py is not good - the tight coupling between transcription and translation makes the code less maintainable and less efficient. I actually started addressing some architectural issues in commit c7db967, but there's still room for improvement.

Feel free to open a PR with your proposed changes!