speech_api.py

from fastapi import APIRouter, File, UploadFile, HTTPException
from fastapi.responses import StreamingResponse
from pydantic import BaseModel
from ai4b import BhashiniClient
from fast_langdetect import detect
import io
import base64
import os

router = APIRouter()

ULCA_USER_ID = os.getenv("ULCA_USER_ID")
ULCA_API_KEY = os.getenv("ULCA_API_KEY")

client = BhashiniClient(user_id=ULCA_USER_ID, api_key=ULCA_API_KEY)

class TTSRequest(BaseModel):
    text: str
    voice: str = "female"

SUPPORTED_LANGUAGES = {'pa', 'mr', 'bn', 'en', 'as', 'or', 'ta', 'te', 'kn', 'gu', 'hi', 'ml'}

def detect_language(text):
    text = text.replace("\n", " ")
    try:
        result = detect(text, low_memory=False)
        detected_lang = result['lang']
        if detected_lang in SUPPORTED_LANGUAGES:
            return detected_lang
    except:
        pass

    if any('\u0980' <= char <= '\u09FF' for char in text):
        return 'brx'
    elif any('\uABC0' <= char <= '\uABFF' for char in text):
        return 'mni'
    
    return 'en'

@router.post("/tts")
async def text_to_speech(request: TTSRequest):
    try:
        detected_language = detect_language(request.text)
        
        tts_result = client.tts(
            request.text,
            source_language=detected_language,
            gender=request.voice
        )
        
        audio_base64 = tts_result['pipelineResponse'][0]['audio'][0]['audioContent']
        audio_data = base64.b64decode(audio_base64)
        
        return StreamingResponse(io.BytesIO(audio_data), media_type="audio/wav")
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@router.post("/asr")
async def speech_to_text(file: UploadFile = File(...), source_language: str = "en"):
    try:
        audio_content = await file.read()
        asr_result = client.asr(audio_content, source_language=source_language)
        
        # Extract the transcribed text from the complex JSON structure
        transcribed_text = asr_result['pipelineResponse'][0]['output'][0]['source']
        
        return {"text": transcribed_text}
    except KeyError:
        raise HTTPException(status_code=500, detail=f"Unexpected response structure from ASR service out:{asr_result}")
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))