Hi, I'm an engineer at Speechmatics. Our speech-to-text software handles speaker diarization very reliably, and we're a go-to choice for non-English languages. https://www.speechmatics.com/

How long is the audio file? If it's under 2 hours, you can upload the file and transcribe it with diarization for free using our web portal: https://portal.speechmatics.com/jobs/create/batch

Hope it helps for your use case! If it does, and you encounter any issues, drop us an email at devrel@speechmatics.com :)

EDIT: typo