Feature request

It is currently not possible to mix multiple languages in a single batch when running Whisper. The language argument only accepts a single string (as opposed to a separate language for each batch item), and if no language is passed and multiple languages are detected, transcription will fail.

I propose to enable passing a list of languages (language: Optional[Union[str, List[str]]]) in a batched transcription situation, as well as removing the restriction related to language detection.

Motivation

Not being able to transcribe multiple languages in a single batch is clearly a limitation, especially when relying on auto-detection, but also in scenarios where the language is known.

The error message states that It is currently not supported to transcribe to different languages in a single batch., implying that it could be supported at some point.

Your contribution

I have implemented this and I'm planning to submit a PR.