app.py

import io
import math
from typing import Optional

import numpy as np
import spaces
import gradio as gr
import torch

from parler_tts import ParlerTTSForConditionalGeneration
from pydub import AudioSegment
from transformers import AutoTokenizer, AutoFeatureExtractor, set_seed
from huggingface_hub import InferenceClient
import nltk
import random
nltk.download('punkt')


device = "cuda:0" if torch.cuda.is_available() else "mps" if torch.backends.mps.is_available() else "cpu"
torch_dtype = torch.float16 if device != "cpu" else torch.float32

repo_id = "parler-tts/parler_tts_mini_v0.1"

jenny_repo_id = "ylacombe/parler-tts-mini-jenny-30H"

model = ParlerTTSForConditionalGeneration.from_pretrained(
    jenny_repo_id, torch_dtype=torch_dtype, low_cpu_mem_usage=True
).to(device)

client = InferenceClient()

description_tokenizer = AutoTokenizer.from_pretrained(repo_id) 
prompt_tokenizer = AutoTokenizer.from_pretrained(repo_id)
feature_extractor = AutoFeatureExtractor.from_pretrained(repo_id)

SAMPLE_RATE = feature_extractor.sampling_rate
SEED = 42


def numpy_to_mp3(audio_array, sampling_rate):
    # Normalize audio_array if it's floating-point
    if np.issubdtype(audio_array.dtype, np.floating):
        max_val = np.max(np.abs(audio_array)) + 1
        audio_array = (audio_array / max_val) * 32767 # Normalize to 16-bit range
        audio_array = audio_array.astype(np.int16)

    # Create an audio segment from the numpy array
    audio_segment = AudioSegment(
        audio_array.tobytes(),
        frame_rate=sampling_rate,
        sample_width=audio_array.dtype.itemsize,
        channels=1
    )

    # Export the audio segment to MP3 bytes - use a high bitrate to maximise quality
    mp3_io = io.BytesIO()
    audio_segment.export(mp3_io, format="mp3", bitrate="320k")

    # Get the MP3 bytes
    mp3_bytes = mp3_io.getvalue()
    mp3_io.close()

    return mp3_bytes

sampling_rate = model.audio_encoder.config.sampling_rate
frame_rate = model.audio_encoder.config.frame_rate


def generate_story(subject: str, setting: str) -> str:
    messages = [{"role": "sytem", "content": ("You are an award-winning children's bedtime story author lauded for your inventive stories."
                                              "You want to write a bed time story for your child. They will give you the subject and setting "
                                              "and you will write the entire story. It should be targetted at children 5 and younger and take about "
                                              "a minute to read")},
                {"role": "user", "content": f"Please tell me a story about a {subject} in {setting}"}]
    response = client.chat_completion(messages, max_tokens=1024, seed=random.randint(1, 5000))
    gr.Info("Story Generated", duration=3)
    story = response.choices[0].message.content
    return None, None, story


@spaces.GPU
def generate_base(story):


    model_input = story.replace("\n", " ").strip()
    model_input_tokens = nltk.sent_tokenize(model_input)

    play_steps_in_s = 4.0
    play_steps = int(frame_rate * play_steps_in_s)

    gr.Info("Generating Audio", duration=3)
    description = "Jenny speaks at an average pace with a calm delivery in a very confined sounding environment with clear audio quality."
    story_tokens = prompt_tokenizer(model_input_tokens, return_tensors="pt", padding=True).to(device)
    description_tokens = description_tokenizer([description for _ in range(len(model_input_tokens))], return_tensors="pt").to(device)
    speech_output = model.generate(input_ids=description_tokens.input_ids,
                                   prompt_input_ids=story_tokens.input_ids,
                                   attention_mask=description_tokens.attention_mask,
                                   prompt_attention_mask=story_tokens.attention_mask)
    speech_output = [output.cpu().numpy() for output in speech_output]
    return None, None, speech_output


def stream_audio(hidden_story, speech_output):

    gr.Info("Reading Story")

    for new_audio in speech_output:
        print(f"Sample of length: {round(new_audio.shape[0] / sampling_rate, 2)} seconds")
        yield hidden_story, numpy_to_mp3(new_audio, sampling_rate=sampling_rate)


with gr.Blocks() as block:
    gr.HTML(
        f"""
        <h1> Bedtime Story Reader 😴🔊 </h1>
        <p> Powered by <a href="https://github.com/huggingface/parler-tts"> Parler-TTS</a>
        """
    )
    with gr.Group():
        with gr.Row():
            subject = gr.Dropdown(value="Princess", choices=["Prince", "Princess", "Dog", "Cat"], label="Subject")
            setting = gr.Dropdown(value="Forest", choices=["Forest", "Kingdom", "Jungle", "Underwater", "Pirate Ship"], label="Setting")
        with gr.Row():
            run_button = gr.Button("Generate Story", variant="primary")
    with gr.Row():
        with gr.Group():
            audio_out = gr.Audio(label="Bed time story",  streaming=True, autoplay=True)
            story = gr.Textbox(label="Story")

    inputs = [subject, setting]
    outputs = [story, audio_out]
    state = gr.State()
    hidden_story = gr.State()
    run_button.click(generate_story, inputs=inputs, outputs=[story, audio_out, hidden_story]).success(fn=generate_base, inputs=hidden_story, outputs=[story, audio_out, state]).success(stream_audio, inputs=[hidden_story, state], outputs=[story, audio_out])

block.queue()
block.launch(share=True)