Add streaming support for OpenAI audio transcription model

[guanxuc]

Summary

Introduce StreamingTranscriptionModel interface and implement streaming audio transcription in OpenAiAudioTranscriptionModel using the async OpenAI client

Changes

• Add StreamingTranscriptionModel interface with stream methods
• Implement stream method in OpenAiAudioTranscriptionModel via OpenAIClientAsync
• Register OpenAIClientAsync in OpenAiAudioTranscriptionAutoConfiguration
• Add unit and integration tests for streaming transcription

[guanxuc]

Hi @ericbottard @ilayaperumalg ,

Could you please take a look, thanks!

[ilayaperumalg]

This would break the existing TranscriptionModel implementations (if there are custom ones). Hence, I suggest to keep TranscriptionModel independent by having the OpenAiAudioTranscriptionModel implementing TranscriptionModel along with StreamingTranscriptionModel. What do you think?

[guanxuc]

Good point! However, this would lead to inconsistencies with the existing implementations of ChatModel and TextToSpeechModel, which could also cause confusion for users. Could we maintain consistency across the codebase and document this as a breaking change in upgrade-notes.adoc?

[ilayaperumalg]

@guanxuc I understand your perspective to bring in consistency. But, I am sorry that we can't bring breaking changes to 2.0.1. Thanks for the understanding.

[guanxuc]

Hi Ilayaperumal,

Thanks for the feedback! Could we add a default stream method to maintain consistency and avoid bringing breaking changes as shown below? Please let me know if this approach is acceptable. If not, I'd be more than happy to implement your previous excellent suggestions instead.

public interface StreamingTranscriptionModel
		extends StreamingModel<AudioTranscriptionPrompt, AudioTranscriptionResponse> {

	default Flux<AudioTranscriptionResponse> stream(AudioTranscriptionPrompt transcriptionPrompt) {
		return Flux.error(new UnsupportedOperationException("Streaming transcription is not supported"));
	}

}

[guanxuc]

Hi Ilayaperumal,

Thanks for your review and the great suggestions! I've addressed your comments. Could you please take another look? Feel free to reach out if you have any further questions.