utils.py

import os
import json
import tempfile
from google.cloud import texttospeech


def get_credentials():
    creds_json_str = os.getenv("GCP_CREDENTIAL_JSON")  # get json credentials stored as a string

    # create a temporary file
    with tempfile.NamedTemporaryFile(mode="w+", delete=False, suffix=".json") as temp:
        temp.write(creds_json_str)  # write in json format
        temp_filename = temp.name

    return temp_filename

def get_google_tts(text, local_filename):
    # Instantiates a client
    client = texttospeech.TextToSpeechClient()

    # Set the text input to be synthesized
    synthesis_input = texttospeech.SynthesisInput(text=text)

    # Build the voice request, select the language code ("en-US") and the ssml
    # voice gender ("neutral")
    voice = texttospeech.VoiceSelectionParams(
        language_code="ja-JP", ssml_gender=texttospeech.SsmlVoiceGender.NEUTRAL
    )

    # Select the type of audio file you want returned
    audio_config = texttospeech.AudioConfig(
        audio_encoding=texttospeech.AudioEncoding.MP3
    )

    # Perform the text-to-speech request on the text input with the selected
    # voice parameters and audio file type
    response = client.synthesize_speech(
        input=synthesis_input, voice=voice, audio_config=audio_config
    )

    # The response's audio_content is binary.
    with open(local_filename, "wb") as out:
        # Write the response to the output file.
        out.write(response.audio_content)
        print(f'Audio content written to file {local_filename}')

    return local_filename